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Seaho B, Lekwongphaiboon C, Inthakusol W, Prateeptongkum S, Harnying W, Berkessel A, Duangdee N. NMR-based stability evaluation of (E)-1-(3',4'-dimethoxyphenyl)butadiene (DMPBD) from Zingiber cassumunar Roxb. rhizome. Phytochem Anal 2024; 35:579-585. [PMID: 38130156 DOI: 10.1002/pca.3314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/26/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023]
Abstract
INTRODUCTION The active compound (E)-1-(3',4'-dimethoxyphenyl)butadiene (DMPBD) isolated from the rhizomes of Zingiber cassumunar Roxb. has potent anti-inflammatory and anticancer activities. Although DMPBD is one of the promising drug candidates for phytomedicine, its limited stability impedes its widespread use. For the development of new drugs, the assessment of their chemical stability is essential, ensuring they maintain their properties within specified limits throughout the period from production until use. OBJECTIVE In the present study, we aimed to evaluate the stability of DMPBD under various conditions, including different solvents, temperatures, and lighting conditions, to identify the factors affecting stability and optimize the storage and handling conditions. METHODOLOGY DMPBD samples subjected to the different conditions tested were monitored by quantitative 1H NMR (qHNMR), using an internal standard for the determination of the absolute quantity of DMPBD as a function of time and the changes thereof within 1 month. RESULTS Significant decomposition of DMPBD was observed in chloroform-d1, whereas its content remained constant in methanol-d4. The content of DMPBD was maintained upon storage at temperatures below 4°C, both as methanolic solution and in the crude extract. Exposure to light had a slight negative impact on its contents. Some degradation products could be identified as resulting from O2-induced cleavage of the diene moiety. CONCLUSIONS For pharmacological/therapeutic applications, DMPBD should be stored in the form of the crude extract or as a purified material in methanolic solution. Ideally, the storage temperature should be below 4°C and O2 should be excluded.
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Affiliation(s)
- Boonwiset Seaho
- Department of Chemistry, Faculty of Science and Technology, Thammasat University (Rangsit Campus), Pathum Thani, Thailand
| | - Chatkamon Lekwongphaiboon
- Department of Chemistry, Faculty of Science and Technology, Thammasat University (Rangsit Campus), Pathum Thani, Thailand
| | - Wichayasith Inthakusol
- Drug Discovery and Development Center, Office of Advanced Science and Technology, Thammasat University (Rangsit Campus), Pathum Thani, Thailand
- Thammasat University Research Unit in Cannabis and Herbal Products Innovation, Thammasat University (Rangsit Campus), Pathum Thani, Thailand
| | - Saisuree Prateeptongkum
- Department of Chemistry, Faculty of Science and Technology, Thammasat University (Rangsit Campus), Pathum Thani, Thailand
| | - Wacharee Harnying
- Department of Chemistry (Organic Chemistry), University of Cologne, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry), University of Cologne, Cologne, Germany
| | - Nongnaphat Duangdee
- Drug Discovery and Development Center, Office of Advanced Science and Technology, Thammasat University (Rangsit Campus), Pathum Thani, Thailand
- Thammasat University Research Unit in Cannabis and Herbal Products Innovation, Thammasat University (Rangsit Campus), Pathum Thani, Thailand
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2
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Lätsch L, Guda SA, Romankov V, Wartmann C, Neudörfl JM, Dreiser J, Berkessel A, Guda AA, Copéret C. Tracking Coordination Environment and Reaction Intermediates in Homogeneous and Heterogeneous Epoxidation Catalysts via Ti L 2,3-Edge Near-Edge X-ray Absorption Fine Structures. J Am Chem Soc 2024; 146:7456-7466. [PMID: 38447178 DOI: 10.1021/jacs.3c12831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Ti-based molecules and materials are ubiquitous and play a major role in both homogeneous and heterogeneous catalytic processes. Understanding the electronic structures of their active sites (oxidation state, local symmetry, and ligand environment) is key to developing molecular-level structure-property relationships. In that context, X-ray absorption spectroscopy (XAS) offers a unique combination of elemental selectivity and sensitivity to local symmetry. Commonly, for early transition metals such as Ti, K-edge XAS is applied for in situ characterization and subsequent structural analysis with high sensitivity toward tetrahedral species. Ti L2,3-edge spectroscopy is in principle complementary and offers specific opportunities to interrogate the electronic structure of five-and six-coordinated species. It is, however, much more rarely implemented because the use of soft X-rays implies ultrahigh vacuum conditions. Furthermore, the interpretation of the data can be challenging. Here, we show how Ti L2,3-edge spectroscopy can help to obtain unique information about both homogeneous and heterogeneous epoxidation catalysts and develop a molecular-level relationship between spectroscopic signatures and electronic structures. Toward this goal, we first establish a spectral library of molecular Ti reference compounds, comprising various coordination environments with mono- and dimeric Ti species having O, N, and Cl ligands. We next implemented a computational methodology based on multiplet ligand field theory and maximally localized Wannier orbitals benchmarked on our library to understand Ti L2,3-edge spectroscopic signatures. We finally used this approach to track and predict the spectra of catalytically relevant intermediates, focusing on Ti-based olefin epoxidation catalysts.
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Affiliation(s)
- Lukas Lätsch
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 2, CH 8093Zurich, Switzerland
| | - Sergey A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178324, 344090Rostov-on-Don, Russia
| | - Vladyslav Romankov
- Swiss Light Source, Paul Scherrer Institut, CH-5232Villigen, Switzerland
| | - Christina Wartmann
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Jörg-M Neudörfl
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Jan Dreiser
- Swiss Light Source, Paul Scherrer Institut, CH-5232Villigen, Switzerland
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Alexander A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178324, 344090Rostov-on-Don, Russia
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 2, CH 8093Zurich, Switzerland
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Wartmann C, Nandi S, Neudörfl JM, Berkessel A. Titanium Salalen Catalyzed Enantioselective Benzylic Hydroxylation. Angew Chem Int Ed Engl 2023; 62:e202306584. [PMID: 37366111 DOI: 10.1002/anie.202306584] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023]
Abstract
The titanium complex of the cis-1,2-diaminocyclohexane (cis-DACH) derived Berkessel-salalen ligand is a highly efficient and enantioselective catalyst for the asymmetric epoxidation of terminal olefins with hydrogen peroxide ("Berkessel-Katsuki catalyst"). We herein report that this epoxidation catalyst also effects the highly enantioselective hydroxylation of benzylic C-H bonds with hydrogen peroxide. Mechanism-based ligand optimization identified a novel nitro-salalen Ti-catalyst of the highest efficiency ever reported for asymmetric catalytic benzylic hydroxylation, with enantioselectivities of up to 98 % ee, while overoxidation to ketone is marginal. The novel nitro-salalen Ti-catalyst also shows enhanced epoxidation efficiency, as evidenced by e.g. the conversion of 1-decene to its epoxide in 90 % yield with 94 % ee, at a catalyst loading of 0.1 mol-% only.
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Affiliation(s)
- Christina Wartmann
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Shiny Nandi
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Jörg-Martin Neudörfl
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
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4
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Paul M, Thomulka T, Harnying W, Neudörfl JM, Adams CR, Martens J, Berden G, Oomens J, Meijer AJHM, Berkessel A, Schäfer M. Hydrogen Bonding Shuts Down Tunneling in Hydroxycarbenes: A Gas-Phase Study by Tandem-Mass Spectrometry, Infrared Ion Spectroscopy, and Theory. J Am Chem Soc 2023. [PMID: 37235775 DOI: 10.1021/jacs.3c01698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hydroxycarbenes can be generated and structurally characterized in the gas phase by collision-induced decarboxylation of α-keto carboxylic acids, followed by infrared ion spectroscopy. Using this approach, we have shown earlier that quantum-mechanical hydrogen tunneling (QMHT) accounts for the isomerization of a charge-tagged phenylhydroxycarbene to the corresponding aldehyde in the gas phase and above room temperature. Herein, we report the results of our current study on aliphatic trialkylammonio-tagged systems. Quite unexpectedly, the flexible 3-(trimethylammonio)propylhydroxycarbene turned out to be stable─no H-shift to either aldehyde or enol occurred. As supported by density functional theory calculations, this novel QMHT inhibition is due to intramolecular H-bonding of a mildly acidic α-ammonio C-H bonds to the hydroxyl carbene's C-atom (C:···H-C). To further support this hypothesis, (4-quinuclidinyl)hydroxycarbenes were synthesized, whose rigid structure prevents this intramolecular H-bonding. The latter hydroxycarbenes underwent "regular" QMHT to the aldehyde at rates comparable to, e.g., methylhydroxycarbene studied by Schreiner et al. While QMHT has been shown for a number of biological H-shift processes, its inhibition by H-bonding disclosed here may serve for the stabilization of highly reactive intermediates such as carbenes, even as a mechanism for biasing intrinsic selectivity patterns.
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Affiliation(s)
- Mathias Paul
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, Cologne 50939, Germany
| | - Thomas Thomulka
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, Cologne 50939, Germany
| | - Wacharee Harnying
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, Cologne 50939, Germany
| | - Jörg-Martin Neudörfl
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, Cologne 50939, Germany
| | - Charlie R Adams
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Jonathan Martens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, Nijmegen 6525 ED, The Netherlands
| | - Giel Berden
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, Nijmegen 6525 ED, The Netherlands
| | - Jos Oomens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, Nijmegen 6525 ED, The Netherlands
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| | | | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, Cologne 50939, Germany
| | - Mathias Schäfer
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, Cologne 50939, Germany
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5
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Ahrweiler-Sawaryn MC, Biswas A, Frias C, Frias J, Wilke NL, Wilke N, Berkessel A, Prokop A. Novel gold(I) complexes induce apoptosis in leukemia cells via the ROS-induced mitochondrial pathway with an upregulation of Harakiri and overcome multi drug resistances in leukemia and lymphoma cells and sensitize drug resistant tumor cells to apoptosis in vitro. Biomed Pharmacother 2023; 161:114507. [PMID: 36958194 DOI: 10.1016/j.biopha.2023.114507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/02/2023] [Accepted: 03/07/2023] [Indexed: 03/25/2023] Open
Abstract
Gold complexes could be promising for tumor therapy because of their cytotoxic and cytostatic properties. We present novel gold(I) complexes and clarify whether they also show antitumor activity by studying apoptosis induction in different tumor cell lines in vitro, comparing the compounds on resistant cells and analyzing the mechanism of action. We particularly highlight one gold complex that shows cytostatic and cytotoxic effects on leukemia and lymphoma cells already in the nanomolar range, induces apoptosis via the intrinsic signaling pathway, and plays a role in the production of reactive oxygen species. Furthermore, not only did we demonstrate a large number of resistance overcomes on resistant cell lines, but some of these cell lines were significantly more sensitive to the new gold compound. Our results show promising properties for the gold compound as anti-tumor drug and suggest that it can subvert resistance mechanisms and thus targets resistant cells for killing.
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Affiliation(s)
- Marie-C Ahrweiler-Sawaryn
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055 Schwerin, Germany; Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany.
| | - Animesh Biswas
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939 Cologne, Germany
| | - Corazon Frias
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055 Schwerin, Germany; Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany
| | - Jerico Frias
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055 Schwerin, Germany; Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany
| | - Nicola L Wilke
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055 Schwerin, Germany; Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany
| | - Nathalie Wilke
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055 Schwerin, Germany; Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939 Cologne, Germany
| | - Aram Prokop
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055 Schwerin, Germany; Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany; Department of Research, Medical School Hamburg (MSH), University of Applied Sciences and Medical University, Am Kaiserkai 1, 20457, Germany
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6
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Severin F, Fusi GM, Wartmann C, Neudörfl J, Berkessel A. syn
‐Selective Epoxidation of Chiral Terminal Allylic Alcohols with a Titanium Salalen Catalyst and Hydrogen Peroxide. Angew Chem Int Ed Engl 2022; 61:e202201790. [PMID: 35349213 PMCID: PMC9325473 DOI: 10.1002/anie.202201790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Indexed: 12/02/2022]
Abstract
In the Sharpless asymmetric epoxidation of chiral secondary allylic alcohols, one substrate enantiomer is predominantly converted to the anti‐epoxy alcohol. We herein report the first highly syn‐selective epoxidation of terminal allylic alcohols using a titanium salalen complex as catalyst, at room temperature, and aqueous hydrogen peroxide as oxidant. With enantiopure terminal allylic alcohols as substrates, the epoxy alcohols were obtained with up to 98 % yield and up to >99 : 1 dr (syn). Catalyst loadings as low as 1 mol % can be applied without eroding the syn‐diastereoselectivity. Modification of the allylic alcohol to an ether does not affect the diastereoselectivity either [>99 : 1 dr (syn)]. Inverting the catalyst configuration leads to the anti‐product, albeit at lower dr (ca. 20 : 1). The synthetic potential is demonstrated by a short, gram‐scale preparation of a tetrahydrofuran building block with three stereocenters, involving two titanium salalen catalyzed epoxidation steps.
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Affiliation(s)
- Fabian Severin
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Giovanni M. Fusi
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
- Dipartimento di Scienza e Alta Tecnologia—DiSAT Università degli Studi dell'Insubria Via Valleggio 9 22100 Como Italy
| | - Christina Wartmann
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Jörg‐Martin Neudörfl
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
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7
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Wessels A, Klussmann M, Breugst M, Schlörer NE, Berkessel A. Inside Back Cover: Formation of Breslow Intermediates from N‐Heterocyclic Carbenes and Aldehydes Involves Autocatalysis by the Breslow Intermediate, and a Hemiacetal (Angew. Chem. Int. Ed. 23/2022). Angew Chem Int Ed Engl 2022. [DOI: 10.1002/anie.202205351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Alina Wessels
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Martin Klussmann
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
- Borchers GmbH Berghausener Straße 100 40764 Langenfeld Germany
| | - Martin Breugst
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Nils E. Schlörer
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
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8
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Wessels A, Klussmann M, Breugst M, Schlörer NE, Berkessel A. Formation of Breslow Intermediates from N‐Heterocyclic Carbenes and Aldehydes Involves Autocatalysis by the Breslow Intermediate, and a Hemiacetal. Angew Chem Int Ed Engl 2022; 61:e202117682. [PMID: 35238462 PMCID: PMC9325009 DOI: 10.1002/anie.202117682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Indexed: 11/23/2022]
Abstract
Under aprotic conditions, the stoichiometric reaction of N‐heterocyclic carbenes (NHCs) such as imidazolidin‐2‐ylidenes with aldehydes affords Breslow Intermediates (BIs), involving a formal 1,2‐C‐to‐O proton shift. We herein report kinetic studies (NMR), complemented by DFT calculations, on the mechanism of this kinetically disfavored H‐translocation. Variable time normalization analysis (VTNA) revealed that the kinetic orders of the reactants vary for different NHC‐to‐aldehyde ratios, indicating different and ratio‐dependent mechanistic regimes. We propose that for high NHC‐to‐aldehyde ratios, the H‐shift takes place in the primary, zwitterionic NHC‐aldehyde adduct. With excess aldehyde, the zwitterion is in equilibrium with a hemiacetal, in which the H‐shift occurs. In both regimes, the critical H‐shift is auto‐catalyzed by the BI. Kinetic isotope effects observed for R‐CDO are in line with our proposal. Furthermore, we detected an H‐bonded complex of the BI with excess NHC (NMR).
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Affiliation(s)
- Alina Wessels
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Martin Klussmann
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
- Borchers GmbH Berghausener Straße 100 40764 Langenfeld Germany
| | - Martin Breugst
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Nils E. Schlörer
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
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9
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Severin F, Fusi GM, Wartmann C, Neudörfl J, Berkessel A. syn
‐Selective Epoxidation of Chiral Terminal Allylic Alcohols with a Titanium Salalen Catalyst and Hydrogen Peroxide. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Fabian Severin
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Giovanni M. Fusi
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
- Dipartimento di Scienza e Alta Tecnologia—DiSAT Università degli Studi dell'Insubria Via Valleggio 9 22100 Como Italy
| | - Christina Wartmann
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Jörg‐Martin Neudörfl
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
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10
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Wessels A, Klussmann M, Breugst M, Schlörer NE, Berkessel A. Die Bildung von Breslow‐Intermediaten aus N‐heterocyclischen Carbenen und Aldehyden verläuft autokatalytisch und mit einem Halbacetal als Intermediat. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alina Wessels
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Martin Klussmann
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
- Borchers GmbH Berghausener Straße 100 40764 Langenfeld Deutschland
| | - Martin Breugst
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Nils E. Schlörer
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Albrecht Berkessel
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
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11
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Wessels A, Klussmann M, Breugst M, Schlörer NE, Berkessel A. Innenrücktitelbild: Die Bildung von Breslow‐Intermediaten aus N‐heterocyclischen Carbenen und Aldehyden verläuft autokatalytisch und mit einem Halbacetal als Intermediat (Angew. Chem. 23/2022). Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Alina Wessels
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Martin Klussmann
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
- Borchers GmbH Berghausener Straße 100 40764 Langenfeld Deutschland
| | - Martin Breugst
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Nils E. Schlörer
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Albrecht Berkessel
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
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12
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van Outersterp R, Engelke UF, Merx J, Berden G, Paul M, Thomulka T, Berkessel A, Huigen MC, Kluijtmans LA, Mecinović J, Rutjes FP, van Karnebeek CD, Wevers RA, Boltje TJ, Coene KL, Martens J, Oomens J. Metabolite Identification Using Infrared Ion Spectroscopy─Novel Biomarkers for Pyridoxine-Dependent Epilepsy. Anal Chem 2021; 93:15340-15348. [PMID: 34756024 PMCID: PMC8613736 DOI: 10.1021/acs.analchem.1c02896] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/25/2021] [Indexed: 11/30/2022]
Abstract
Untargeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics strategies are being increasingly applied in metabolite screening for a wide variety of medical conditions. The long-standing "grand challenge" in the utilization of this approach is metabolite identification─confidently determining the chemical structures of m/z-detected unknowns. Here, we use a novel workflow based on the detection of molecular features of interest by high-throughput untargeted LC-MS analysis of patient body fluids combined with targeted molecular identification of those features using infrared ion spectroscopy (IRIS), effectively providing diagnostic IR fingerprints for mass-isolated targets. A significant advantage of this approach is that in silico-predicted IR spectra of candidate chemical structures can be used to suggest the molecular structure of unknown features, thus mitigating the need for the synthesis of a broad range of physical reference standards. Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an inborn error of lysine metabolism, resulting from a mutation in the ALDH7A1 gene that leads to an accumulation of toxic levels of α-aminoadipic semialdehyde (α-AASA), piperideine-6-carboxylate (P6C), and pipecolic acid in body fluids. While α-AASA and P6C are known biomarkers for PDE in urine, their instability makes them poor candidates for diagnostic analysis from blood, which would be required for application in newborn screening protocols. Here, we use combined untargeted metabolomics-IRIS to identify several new biomarkers for PDE-ALDH7A1 that can be used for diagnostic analysis in urine, plasma, and cerebrospinal fluids and that are compatible with analysis in dried blood spots for newborn screening. The identification of these novel metabolites has directly provided novel insights into the pathophysiology of PDE-ALDH7A1.
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Affiliation(s)
- Rianne
E. van Outersterp
- Institute
for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Udo F.H. Engelke
- Department
of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Jona Merx
- Institute
for Molecules and Materials, Synthetic Organic Chemistry, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Giel Berden
- Institute
for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Mathias Paul
- Department
of Chemistry, University of Cologne, Greinstrasse 4, 50939 Cologne, Germany
| | - Thomas Thomulka
- Department
of Chemistry, University of Cologne, Greinstrasse 4, 50939 Cologne, Germany
| | - Albrecht Berkessel
- Department
of Chemistry, University of Cologne, Greinstrasse 4, 50939 Cologne, Germany
| | - Marleen C.D.G. Huigen
- Department
of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Leo A.J. Kluijtmans
- Department
of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Jasmin Mecinović
- University
of Southern Denmark, Department of Physics,
Chemistry and Pharmacy, Campusvej 55, 5230 Odense, Denmark
| | - Floris P.J.T. Rutjes
- Institute
for Molecules and Materials, Synthetic Organic Chemistry, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Clara D.M. van Karnebeek
- Department
of Pediatrics-Metabolic Diseases, Radboud Center for Mitochondrial
Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Ron A. Wevers
- Department
of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Thomas J. Boltje
- Institute
for Molecules and Materials, Synthetic Organic Chemistry, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Karlien L.M. Coene
- Department
of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Jonathan Martens
- Institute
for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Jos Oomens
- Institute
for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
- van’t
Hoff Institute for Molecular Sciences, University
of Amsterdam, Science
Park 908, 1098XH Amsterdam, The Netherlands
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13
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Harnying W, Sudkaow P, Biswas A, Berkessel A. N-Heterocyclic Carbene/Carboxylic Acid Co-Catalysis Enables Oxidative Esterification of Demanding Aldehydes/Enals, at Low Catalyst Loading. Angew Chem Int Ed Engl 2021; 60:19631-19636. [PMID: 34010504 PMCID: PMC8457137 DOI: 10.1002/anie.202104712] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/10/2021] [Indexed: 01/07/2023]
Abstract
We report the discovery that simple carboxylic acids, such as benzoic acid, boost the activity of N-heterocyclic carbene (NHC) catalysts in the oxidative esterification of aldehydes. A simple and efficient protocol for the transformation of a wide range of sterically hindered α- and β-substituted aliphatic aldehydes/enals, catalyzed by a novel and readily accessible N-Mes-/N-2,4,6-trichlorophenyl 1,2,4-triazolium salt, and benzoic acid as co-catalyst, was developed. A whole series of α/β-substituted aliphatic aldehydes/enals hitherto not amenable to NHC-catalyzed esterification could be reacted at typical catalyst loadings of 0.02-1.0 mol %. For benzaldehyde, even 0.005 mol % of NHC catalyst proved sufficient: the lowest value ever achieved in NHC catalysis. Preliminary studies point to carboxylic acid-induced acceleration of acyl transfer from azolium enolate intermediates as the mechanistic basis of the observed effect.
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Affiliation(s)
- Wacharee Harnying
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Panyapon Sudkaow
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Animesh Biswas
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
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14
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Harnying W, Sudkaow P, Biswas A, Berkessel A. N‐Heterocyclic Carbene/Carboxylic Acid Co‐Catalysis Enables Oxidative Esterification of Demanding Aldehydes/Enals, at Low Catalyst Loading. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Wacharee Harnying
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Panyapon Sudkaow
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Animesh Biswas
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
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15
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Hopff SM, Wang Q, Frias C, Ahrweiler M, Wilke N, Wilke N, Berkessel A, Prokop A. A metal-free salalen ligand with anti-tumor and synergistic activity in resistant leukemia and solid tumor cells via mitochondrial pathway. J Cancer Res Clin Oncol 2021; 147:2591-2607. [PMID: 34213662 PMCID: PMC8310854 DOI: 10.1007/s00432-021-03679-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 05/27/2021] [Indexed: 12/15/2022]
Abstract
PURPOSE Since the discovery of the well-known cis-platin, transition metal complexes are highly recognized as cytostatic agents. However, toxic side effects of the metal ions present in the complexes may pose significant problems for their future development. Therefore, we investigated the metal-free salalen ligand WQF 044. METHODS DNA fragmentations in leukemia (Nalm6) and solid tumor cells (BJAB, MelHO, MCF-7, RM82) proved the apoptotic effects of WQF 044, its overcoming of resistances and the cellular pathways that are affected by the substance. The apoptotic mechanisms finding were supported by western blot analysis, measurement of the mitochondrial membrane potential and polymerase chain reactions. RESULTS A complex intervention in the mitochondrial pathway of apoptosis with a Bcl-2 and caspase dependence was observed. Additionally, a wide range of tumors were affected by the ligand in a low micromolar range in-vitro. The compound overcame multidrug resistances in P-gp over-expressed acute lymphoblastic leukemia and CD95-downregulated Ewing's sarcoma cells. Quite remarkable synergistic effects with vincristine were observed in Burkitt-like lymphoma cells. CONCLUSION The investigation of a metal-free salalen ligand as a potential anti-cancer drug revealed in promising results for a future clinical use.
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Affiliation(s)
- Sina M Hopff
- Department of Pediatric Hematology/Oncology, Municipal Clinics of Cologne, Children's Hospital of the City Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany.
| | - Qifang Wang
- Department of Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Corazon Frias
- Department of Pediatric Hematology/Oncology, Municipal Clinics of Cologne, Children's Hospital of the City Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany
| | - Marie Ahrweiler
- Department of Pediatric Hematology/Oncology, Municipal Clinics of Cologne, Children's Hospital of the City Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany
| | - Nicola Wilke
- Department of Pediatric Hematology/Oncology, Municipal Clinics of Cologne, Children's Hospital of the City Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany
| | - Nathalie Wilke
- Department of Pediatric Hematology/Oncology, Municipal Clinics of Cologne, Children's Hospital of the City Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Aram Prokop
- Department of Pediatric Hematology/Oncology, Municipal Clinics of Cologne, Children's Hospital of the City Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055, Schwerin, Germany
- Medical School Hamburg (MSH), University of Applied Sciences and Medical University, Am Kaiserkai 1, 20457, Hamburg, Germany
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16
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Eitzinger A, Otevrel J, Haider V, Macchia A, Massa A, Faust K, Spingler B, Berkessel A, Waser M. Enantioselective Bifunctional Ammonium Salt-Catalyzed Syntheses of 3-CF 3S-, 3-RS-, and 3-F-Substituted Isoindolinones. Adv Synth Catal 2021; 363:1955-1962. [PMID: 33897314 PMCID: PMC8050839 DOI: 10.1002/adsc.202100029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/09/2021] [Indexed: 01/12/2023]
Abstract
We herein report the ammonium salt-catalyzed synthesis of chiral 3,3-disubstituted isoindolinones bearing a heteroatom functionality in the 3-position. A broad variety of differently substituted CF3S- and RS-derivatives were obtained with often high enantioselectivities when using Maruoka's bifunctional chiral ammonium salt catalyst. In addition, a first proof-of-concept for the racemic synthesis of the analogous F-containing products was obtained as well, giving access to one of the rare examples of a fairly stable α-F-α-amino acid derivative.
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Affiliation(s)
- Andreas Eitzinger
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Jan Otevrel
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
- Department of Chemical DrugsFaculty of PharmacyMasaryk UniversityPalackeho 1946/1612 00BrnoCzechia
| | - Victoria Haider
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Antonio Macchia
- Dipartimento di Chimica e BiologiaUniversità di SalernoVia Giovanni Paolo II, 13284084FiscianoSAItaly
| | - Antonio Massa
- Dipartimento di Chimica e BiologiaUniversità di SalernoVia Giovanni Paolo II, 13284084FiscianoSAItaly
| | - Kirill Faust
- Institute of CatalysisJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Bernhard Spingler
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZurichSwitzerland
| | - Albrecht Berkessel
- Department of ChemistryCologne UniversityGreinstrasse 450939CologneGermany
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
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17
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Engler H, Lansing M, Gordon CP, Neudörfl JM, Schäfer M, Schlörer NE, Copéret C, Berkessel A. Olefin Epoxidation Catalyzed by Titanium–Salalen Complexes: Synergistic H 2O 2 Activation by Dinuclear Ti Sites, Ligand H-Bonding, and π-Acidity. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05320] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Hauke Engler
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Markus Lansing
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Christopher P. Gordon
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Jörg-M. Neudörfl
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Mathias Schäfer
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Nils E. Schlörer
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Albrecht Berkessel
- Department of Chemistry, Cologne University, Greinstraße 4, 50939 Cologne, Germany
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18
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Biswas A, Neudörfl JM, Schlörer NE, Berkessel A. Acyl Donor Intermediates in N-Heterocyclic Carbene Catalysis: Acyl Azolium or Azolium Enolate? Angew Chem Int Ed Engl 2021; 60:4507-4511. [PMID: 33140529 PMCID: PMC7986403 DOI: 10.1002/anie.202010348] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/20/2020] [Indexed: 11/23/2022]
Abstract
Azolium enolates and acyl azolium cations have been proposed as intermediates in numerous N‐heterocyclic carbene (NHC) catalyzed transformations. Acetyl azolium enolates were generated from the reaction of 2‐propenyl acetate with both saturated (SIPr) and aromatic (IPr) NHCs, isolated, and characterized (NMR, XRD). Protonation with triflic acid gave the corresponding acetyl azolium triflates which were isolated and characterized (NMR, XRD). Acyl azolium cations have been proposed as immediate precursors of the ester product, for example, in the redox esterification of α,β‐enals. Studies with d3‐acetyl azolium triflate suggest that ester formation originates instead from an azolium enolate intermediate. Furthermore, the acetyl azolium enolate selectively reacted with alcohol nucleophiles in the presence of amines. While the acetyl azolium cation did not react with alcohols, an ester‐selective reaction was induced by addition of base, by intermediate formation of the acetyl azolium enolate.
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Affiliation(s)
- Animesh Biswas
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Jörg-M Neudörfl
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Nils E Schlörer
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry), University of Cologne, Greinstraße 4, 50939, Cologne, Germany
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19
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Biswas A, Neudörfl J, Schlörer NE, Berkessel A. Acyl Donor Intermediates in N‐Heterocyclic Carbene Catalysis: Acyl Azolium or Azolium Enolate? Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202010348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Animesh Biswas
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Jörg‐M. Neudörfl
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Nils E. Schlörer
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry) University of Cologne Greinstraße 4 50939 Cologne Germany
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20
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Hopff SM, Onambele LA, Brandenburg M, Berkessel A, Prokop A. Sensitizing multidrug-resistant leukemia cells to common cytostatics by an aluminium-salen complex that has high-apoptotic effects in leukemia, lymphoma and mamma carcinoma cells. Biometals 2021; 34:211-220. [PMID: 33560473 DOI: 10.1007/s10534-020-00273-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 11/18/2020] [Indexed: 11/25/2022]
Abstract
We investigated the aluminium-salen complex MBR-8 as a potential anti-cancer agent. To see apoptotic effects induced by MBR-8, alone and in combination with common cytostatic drugs, DNA-fragmentations were studied using the flow cytometric analysis. Western blot analysis and measurement of the mitochondrial membrane potential with a JC-1 dye were employed to identify the pathway of apoptosis. An impressive overcoming of multidrug-resistance in leukemia (Nalm6) cells was observed. Additionally, solid tumor cells including Burkitt-like lymphoma (BJAB) and mamma carcinoma cells (MCF-7) are affected by MBR-8 in the same way. Western blot analysis revealed activation of caspase-3. MBR-8 showed very pronounced selectivity with regard to tumor cells and high synergistic effects in Nalm6 and daunorubicin-resistant Nalm6 cells when administered in combination with vincristine, daunorubicin and doxorubicin. The aluminium-salen complex MBR-8 showed very promising anti-cancer properties which warrant further development towards a cytostatic agent for future chemotherapy. Studies on aluminium compounds for cancer therapy are rare, and our report adds to this important body of knowledge.
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Affiliation(s)
- Sina M Hopff
- Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany.
| | - Liliane A Onambele
- Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany
| | - Marc Brandenburg
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Aram Prokop
- Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735, Cologne, Germany
- Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055, Schwerin, Germany
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21
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Paul M, Peckelsen K, Thomulka T, Martens J, Berden G, Oomens J, Neudörfl JM, Breugst M, Meijer AJHM, Schäfer M, Berkessel A. Breslow Intermediates (Amino Enols) and Their Keto Tautomers: First Gas-Phase Characterization by IR Ion Spectroscopy. Chemistry 2021; 27:2662-2669. [PMID: 32893891 PMCID: PMC7898712 DOI: 10.1002/chem.202003454] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/01/2020] [Indexed: 12/11/2022]
Abstract
Breslow intermediates (BIs) are the crucial nucleophilic amino enol intermediates formed from electrophilic aldehydes in the course of N-heterocyclic carbene (NHC)-catalyzed umpolung reactions. Both in organocatalytic and enzymatic umpolung, the question whether the Breslow intermediate exists as the nucleophilic enol or in the form of its electrophilic keto tautomer is of utmost importance for its reactivity and function. Herein, the preparation of charge-tagged Breslow intermediates/keto tautomers derived from three different types of NHCs (imidazolidin-2-ylidenes, 1,2,4-triazolin-5-ylidenes, thiazolin-2-ylidenes) and aldehydes is reported. An ammonium charge tag is introduced through the aldehyde unit or the NHC. ESI-MS IR ion spectroscopy allowed the unambiguous conclusion that in the gas phase, the imidazolidin-2-ylidene-derived BI indeed exists as a diamino enol, while both 1,2,4-triazolin-5-ylidenes and thiazolin-2-ylidenes give the keto tautomer. This result coincides with the tautomeric states observed for the BIs in solution (NMR) and in the crystalline state (XRD), and is in line with our earlier calculations on the energetics of BI keto-enol equilibria.
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Affiliation(s)
- Mathias Paul
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Cologne, Germany
| | - Katrin Peckelsen
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Cologne, Germany
| | - Thomas Thomulka
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Cologne, Germany
| | - Jonathan Martens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525, ED, Nijmegen, The Netherlands
| | - Giel Berden
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525, ED, Nijmegen, The Netherlands
| | - Jos Oomens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525, ED, Nijmegen, The Netherlands.,Van' t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Jörg-M Neudörfl
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Cologne, Germany
| | - Martin Breugst
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Cologne, Germany
| | | | - Mathias Schäfer
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Cologne, Germany
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22
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Paul M, Peckelsen K, Thomulka T, Martens J, Berden G, Oomens J, Neudörfl J, Breugst M, Meijer AJHM, Schäfer M, Berkessel A. Cover Feature: Breslow Intermediates (Amino Enols) and Their Keto Tautomers: First Gas‐Phase Characterization by IR Ion Spectroscopy (Chem. Eur. J. 8/2021). Chemistry 2021. [DOI: 10.1002/chem.202004678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mathias Paul
- Department of Chemistry Cologne University Greinstrasse 4 50939 Cologne Germany
| | - Katrin Peckelsen
- Department of Chemistry Cologne University Greinstrasse 4 50939 Cologne Germany
| | - Thomas Thomulka
- Department of Chemistry Cologne University Greinstrasse 4 50939 Cologne Germany
| | - Jonathan Martens
- Institute for Molecules and Materials FELIX Laboratory Radboud University Toernooiveld 7 6525 ED Nijmegen The Netherlands
| | - Giel Berden
- Institute for Molecules and Materials FELIX Laboratory Radboud University Toernooiveld 7 6525 ED Nijmegen The Netherlands
| | - Jos Oomens
- Institute for Molecules and Materials FELIX Laboratory Radboud University Toernooiveld 7 6525 ED Nijmegen The Netherlands
- Van' t Hoff Institute for Molecular Sciences University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands
| | - Jörg‐M. Neudörfl
- Department of Chemistry Cologne University Greinstrasse 4 50939 Cologne Germany
| | - Martin Breugst
- Department of Chemistry Cologne University Greinstrasse 4 50939 Cologne Germany
| | | | - Mathias Schäfer
- Department of Chemistry Cologne University Greinstrasse 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry Cologne University Greinstrasse 4 50939 Cologne Germany
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23
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Gordon CP, Engler H, Tragl AS, Plodinec M, Lunkenbein T, Berkessel A, Teles JH, Parvulescu AN, Copéret C. Efficient epoxidation over dinuclear sites in titanium silicalite-1. Nature 2020; 586:708-713. [PMID: 33116285 DOI: 10.1038/s41586-020-2826-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 08/26/2020] [Indexed: 11/09/2022]
Abstract
Titanium silicalite-1 (TS-1) is a zeolitic material with MFI framework structure, in which 1 to 2 per cent of the silicon atoms are substituted for titanium atoms. It is widely used in industry owing to its ability to catalytically epoxidize olefins with hydrogen peroxide (H2O2), leaving only water as a byproduct1,2; around one million tonnes of propylene oxide are produced each year using this process3. The catalytic properties of TS-1 are generally attributed to the presence of isolated Ti(IV) sites within the zeolite framework1. However, despite almost 40 years of experimental and computational investigation4-10, the structure of these active Ti(IV) sites is unconfirmed, owing to the challenges of fully characterizing TS-1. Here, using a combination of spectroscopy and microscopy, we characterize in detail a series of highly active and selective TS-1 propylene epoxidation catalysts with well dispersed titanium atoms. We find that, on contact with H217O2, all samples exhibit a characteristic solid-state 17O nuclear magnetic resonance signature that is indicative of the formation of bridging peroxo species on dinuclear titanium sites. Further, density functional theory calculations indicate that cooperativity between two titanium atoms enables propylene epoxidation via a low-energy reaction pathway with a key oxygen-transfer transition state similar to that of olefin epoxidation by peracids. We therefore propose that dinuclear titanium sites, rather than isolated titanium atoms in the framework, explain the high efficiency of TS-1 in propylene epoxidation with H2O2. This revised view of the active-site structure may enable further optimization of TS-1 and the industrial epoxidation process.
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Affiliation(s)
- Christopher P Gordon
- Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, Switzerland
| | - Hauke Engler
- Department of Chemistry, Cologne University, Cologne, Germany
| | - Amadeus Samuel Tragl
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Milivoj Plodinec
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Thomas Lunkenbein
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | | | | | | | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, Switzerland.
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24
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Hopff SM, Onambele LA, Brandenburg M, Berkessel A, Prokop A. Discovery of a cobalt (III) salen complex that induces apoptosis in Burkitt like lymphoma and leukemia cells, overcoming multidrug resistance in vitro. Bioorg Chem 2020; 104:104193. [PMID: 32947134 DOI: 10.1016/j.bioorg.2020.104193] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/19/2020] [Accepted: 08/02/2020] [Indexed: 01/09/2023]
Abstract
A very small number of cobalt complexes is examined in oncology research. In this work, we investigate the cobalt (III) salen complex MBR-60 that turns out to be a promising anticancer drug. It induces apoptosis in Nalm6 leukemia and BJAB lymphoma cells and overcomes multidrug resistances by blocking the drug efflux pump P-glycoprotein. It further develops the apoptotic effects over the intrinsic pathway. An activation of caspase-3, caspase-8 and caspase-9 can be detected by western blot analysis. The independence of CD95 is shown by similar apoptotic inductions in BJAB and BJAB FADDdn cells. MBR-60 displays synergistic effects with daunorubicin and vincristine and has a selectivity to tumor cells. In comparison to the apoptotic effects of MBR-60 in BJAB lymphoma cells, the cobalt-free ligand 5 does not influence these cells. The research highlights that a cobalt complex has a therapeutic potential for cancer treating with a focus on drug-resistant tumors.
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Affiliation(s)
- Sina M Hopff
- Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany.
| | - Liliane A Onambele
- Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany
| | - Marc Brandenburg
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Aram Prokop
- Department of Pediatric Hematology/Oncology, Children's Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany; Department of Pediatric Hematology/Oncology, Helios Clinic Schwerin, Wismarsche Straße 393-397, 19055 Schwerin, Germany
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25
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Basova S, Wilke N, Koch JC, Prokop A, Berkessel A, Pradel G, Ngwa CJ. Organoarsenic Compounds with In Vitro Activity against the Malaria Parasite Plasmodium falciparum. Biomedicines 2020; 8:biomedicines8080260. [PMID: 32748808 PMCID: PMC7459655 DOI: 10.3390/biomedicines8080260] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/24/2020] [Accepted: 07/29/2020] [Indexed: 01/16/2023] Open
Abstract
The rapid development of parasite drug resistance as well as the lack of medications targeting both the asexual and the sexual blood stages of the malaria parasite necessitate the search for novel antimalarial compounds. Eleven organoarsenic compounds were synthesized and tested for their effect on the asexual blood stages and sexual transmission stages of the malaria parasite Plasmodium falciparum using in vitro assays. The inhibitory potential of the compounds on blood stage viability was tested on the chloroquine (CQ)-sensitive 3D7 and the CQ-resistant Dd2 strain using the Malstat assay. The most effective compounds were subsequently investigated for their effect on impairing gametocyte development and gametogenesis, using the gametocyte-producing NF54 strain in respective cell-based assays. Their potential toxicity was investigated on leukemia cell line Nalm-6 and non-infected erythrocytes. Five out of the 11 compounds showed antiplasmodial activities against 3D7, with half-maximal inhibitory concentration (IC50) values ranging between 1.52 and 8.64 µM. Three of the compounds also acted against Dd2, with the most active compound As-8 exhibiting an IC50 of 0.35 µM. The five compounds also showed significant inhibitory effects on the parasite sexual stages at both IC50 and IC90 concentrations with As-8 displaying the best gametocytocidal activity. No hemolytic and cytotoxic effect was observed for any of the compounds. The organoarsenic compound As-8 may represent a good lead for the design of novel organoarsenic drugs with combined antimalarial and transmission blocking activities.
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Affiliation(s)
- Sofia Basova
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; (S.B.); (G.P.)
| | - Nathalie Wilke
- Department of Paediatric Oncology, Children’s Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany; (N.W.); (A.P.)
| | - Jan Christoph Koch
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany; (J.C.K.); (A.B.)
| | - Aram Prokop
- Department of Paediatric Oncology, Children’s Hospital Cologne, Amsterdamer Straße 59, 50735 Cologne, Germany; (N.W.); (A.P.)
- Department of Paediatric Oncology, Helios Hospital Schwerin, Wismarsche Strasse 393-397, 19049 Schwerin, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany; (J.C.K.); (A.B.)
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; (S.B.); (G.P.)
| | - Che Julius Ngwa
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; (S.B.); (G.P.)
- Correspondence:
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26
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Abstract
An efficient oxidative NHC-catalyzed one-step transformation of (S)- or (R)-8-oxocitronellal to nepetalactone (NL) in enantio- and diastereomerically pure form has been developed. Several new and "easy to make" N-Mes- or N-Dipp-substituted 1,2,4-triazolium salts carrying nitroaromatic groups on N1 were synthesized and evaluated as precatalysts in combination with base and stoichiometric organic oxidant. Under optimized conditions, NLs are accessible in very good yields and diastereomerically pure under mild conditions. The oxidant used could be recovered and recycled under operationally simple conditions.
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Affiliation(s)
- Wacharee Harnying
- Department of Chemistry (Organic Chemistry) , University of Cologne , Greinstrasse 4 , 50939 Cologne , Germany
| | - Jörg-M Neudörfl
- Department of Chemistry (Organic Chemistry) , University of Cologne , Greinstrasse 4 , 50939 Cologne , Germany
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry) , University of Cologne , Greinstrasse 4 , 50939 Cologne , Germany
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27
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Thrun F, Hickmann V, Stock C, Schäfer A, Maier W, Breugst M, Schlörer NE, Berkessel A, Teles JH. Technical Synthesis of 1,5,9-Cyclododecatriene Revisited: Surprising Byproducts from a Venerable Industrial Process. J Org Chem 2019; 84:13211-13220. [DOI: 10.1021/acs.joc.9b01633] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Frauke Thrun
- Process Research and Chemical Engineering, BASF SE, 67056 Ludwigshafen, Germany
| | - Volker Hickmann
- Process Research and Chemical Engineering, BASF SE, 67056 Ludwigshafen, Germany
| | - Christoph Stock
- Process Research and Chemical Engineering, BASF SE, 67056 Ludwigshafen, Germany
| | | | - Walter Maier
- Competence Center Analytics, Physics & Formulation, BASF SE, 67056 Ludwigshafen, Germany
| | - Martin Breugst
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Nils E. Schlörer
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
| | - J. Henrique Teles
- Process Research and Chemical Engineering, BASF SE, 67056 Ludwigshafen, Germany
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28
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Paul M, Peckelsen K, Thomulka T, Neudörfl J, Martens J, Berden G, Oomens J, Berkessel A, Meijer AJHM, Schäfer M. Hydrogen tunneling avoided: enol-formation from a charge-tagged phenyl pyruvic acid derivative evidenced by tandem-MS, IR ion spectroscopy and theory. Phys Chem Chem Phys 2019; 21:16591-16600. [PMID: 31317140 DOI: 10.1039/c9cp02316j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A charge-tagged phenyl pyruvic acid derivative was investigated by tandem-MS, infrared (IR) ion spectroscopy and theory. The tailor-made precursor ions efficiently lose CO2 in collision induced dissociation (CID) experiments, offering access to study the secondary decay reactions of the product ions. IR ion spectroscopy provides evidence for the formation of an enol acid precursor ion structure in the gas phase and indicates the presence of enol products formed after CO2 loss. Extensive DFT computations however, suggest intermediate generation of hydroxycarbene products, which in turn rearrange in a secondary process to the enol ions detected by IR ion spectroscopy. Quantum mechanical tunneling of the hydroxycarbene can be excluded since no evidence for aldehyde product ion formation could be found. This finding is in contrast to the behavior of methylhydroxycarbene, which cleanly penetrates the energy barrier to form exclusively acetaldehyde at cryogenic temperatures in an argon matrix via quantum mechanical hydrogen tunneling. The results presented here are attributed to the highly excited energy levels of the product ions formed by CID in combination with different barrier heights of the competing reaction channels, which allow exclusive access over one energy barrier leading to the formation of the enol tautomer ions observed.
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Affiliation(s)
- Mathias Paul
- University of Cologne, Department of Chemistry, Greinstrasse 4, 50939 Köln, Germany.
| | - Katrin Peckelsen
- University of Cologne, Department of Chemistry, Greinstrasse 4, 50939 Köln, Germany.
| | - Thomas Thomulka
- University of Cologne, Department of Chemistry, Greinstrasse 4, 50939 Köln, Germany.
| | - Jörg Neudörfl
- University of Cologne, Department of Chemistry, Greinstrasse 4, 50939 Köln, Germany.
| | - Jonathan Martens
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - Giel Berden
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - Jos Oomens
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands and Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Albrecht Berkessel
- University of Cologne, Department of Chemistry, Greinstrasse 4, 50939 Köln, Germany.
| | | | - Mathias Schäfer
- University of Cologne, Department of Chemistry, Greinstrasse 4, 50939 Köln, Germany.
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29
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Paul M, Neudörfl JM, Berkessel A. Breslow Intermediates from a Thiazolin-2-ylidene and Fluorinated Aldehydes: XRD and Solution-Phase NMR Spectroscopic Characterization. Angew Chem Int Ed Engl 2019; 58:10596-10600. [PMID: 31131519 DOI: 10.1002/anie.201904308] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/20/2019] [Indexed: 12/20/2022]
Abstract
The first generation and X-ray diffraction (XRD) analysis of a crystalline Breslow intermediate (BI) derived from a thiazolin-2-ylidene, that is, the aromatic heterocycle present in vitamin B1 , is reported. Key to success was the combined use of pentafluorobenzaldehyde and a thiazolin-2-ylidene carrying an enol-stabilizing dispersion energy donor as N-substituent. A so-called primary intermediate (PI) could be isolated in protonated form (pPI) as well and analyzed by XRD. Furthermore, the first stable BI derived from an aromatic thiazolin-2-ylidene and an aliphatic aldehyde (trifluoroacetaldehyde) was prepared and characterized by NMR spectroscopy in solution. When switching to a saturated thiazolidin-2-ylidene, reaction with pentafluorobenzaldehyde afforded a new BI in solution (NMR spectroscopy). Attempts to crystallize the latter BI resulted in the isolation of a novel thiazolidin-2-ylidene dimer that had undergone rearrangement to a hexahydro[1,4]-thiazino[3,2-b]-1,4-thiazine.
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Affiliation(s)
- Mathias Paul
- Cologne University, Department of Chemistry, Greinstrasse 4, 50939, Cologne, Germany
| | - Jörg-M Neudörfl
- Cologne University, Department of Chemistry, Greinstrasse 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Cologne University, Department of Chemistry, Greinstrasse 4, 50939, Cologne, Germany
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30
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Paul M, Neudörfl J, Berkessel A. Breslow Intermediates from a Thiazolin‐2‐ylidene and Fluorinated Aldehydes: XRD and Solution‐Phase NMR Spectroscopic Characterization. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201904308] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Mathias Paul
- Cologne UniversityDepartment of Chemistry Greinstrasse 4 50939 Cologne Germany
| | - Jörg‐M. Neudörfl
- Cologne UniversityDepartment of Chemistry Greinstrasse 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Cologne UniversityDepartment of Chemistry Greinstrasse 4 50939 Cologne Germany
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31
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Paul M, Detmar E, Schlangen M, Breugst M, Neudörfl JM, Schwarz H, Berkessel A, Schäfer M. Intermediates of N-Heterocyclic Carbene (NHC) Dimerization Probed in the Gas Phase by Ion Mobility Mass Spectrometry: C-H⋅⋅⋅:C Hydrogen Bonding Versus Covalent Dimer Formation. Chemistry 2019; 25:2511-2518. [PMID: 30488654 DOI: 10.1002/chem.201803641] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/27/2018] [Indexed: 11/06/2022]
Abstract
N-Heterocyclic carbenes (NHCs, :C) can interact with azolium salts (C-H+ ) by either forming a hydrogen-bonded aggregate (CHC+ ) or a covalent C-C bond (CCH+ ). In this study, the intramolecular NHC-azolium salt interactions of aromatic imidazolin-2-ylidenes and saturated imidazolidin-2-ylidenes have been investigated in the gas phase by traveling wave ion mobility mass spectrometry (TW IMS) and DFT calculations. The TW IMS experiments provided evidence for the formation of these important intermediates in the gas phase, and they identified the predominant aggregation mode (hydrogen bond vs. covalent C-C) as a function of the nature of the interacting carbene-azolium pairs.
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Affiliation(s)
- Mathias Paul
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939, Cologne, Germany
| | - Eric Detmar
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939, Cologne, Germany
| | - Maria Schlangen
- Institute of Chemistry, Technical University Berlin, Straße des 17. Juni 115, 10623, Berlin, Germany
| | - Martin Breugst
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939, Cologne, Germany
| | - Jörg-Martin Neudörfl
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939, Cologne, Germany
| | - Helmut Schwarz
- Institute of Chemistry, Technical University Berlin, Straße des 17. Juni 115, 10623, Berlin, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939, Cologne, Germany
| | - Mathias Schäfer
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstrasse 4, 50939, Cologne, Germany
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32
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Schober L, Ratnam S, Yamashita Y, Adebar N, Pieper M, Berkessel A, Hessel V, Gröger H. An Asymmetric Organocatalytic Aldol Reaction of a Hydrophobic Aldehyde in Aqueous Medium Running in Flow Mode. SYNTHESIS-STUTTGART 2019. [DOI: 10.1055/s-0037-1610404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Reaction conditions have been identified to conduct a one-pot asymmetric organocatalytic aldol reaction with a hydrophobic substrate in aqueous medium via a process running in flow mode. By employing a mixture of water and 2-propanol, a hydrophobic aldehyde and 3.6 mol% of an organocatalyst, this microreactor process affords the desired aldol adduct with a conversion of 74% and an enantioselectivity of 89% after a reaction time of 60 minutes.
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Affiliation(s)
- Lukas Schober
- Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University
| | - Shahilan Ratnam
- Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University
| | - Yasunobu Yamashita
- Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University
| | - Niklas Adebar
- Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University
| | - Matthias Pieper
- Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University
| | | | - Volker Hessel
- Micro Flow Chemistry & Process Technology, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology
| | - Harald Gröger
- Chair of Organic Chemistry I, Faculty of Chemistry, Bielefeld University
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33
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Paul M, Sudkaow P, Wessels A, Schlörer NE, Neudörfl J, Berkessel A. Rücktitelbild: Breslow‐Intermediate aromatischer N‐heterocyclischer Carbene (Benzimidazolin‐2‐ylidene, Thiazolin‐2‐ylidene) (Angew. Chem. 27/2018). Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Mathias Paul
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Panyapon Sudkaow
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Alina Wessels
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Nils E. Schlörer
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Jörg‐M. Neudörfl
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Albrecht Berkessel
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
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34
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Paul M, Sudkaow P, Wessels A, Schlörer NE, Neudörfl J, Berkessel A. Breslow Intermediates from Aromatic N‐Heterocyclic Carbenes (Benzimidazolin‐2‐ylidenes, Thiazolin‐2‐ylidenes). Angew Chem Int Ed Engl 2018; 57:8310-8315. [PMID: 29645334 DOI: 10.1002/anie.201801676] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Indexed: 12/29/2022]
Affiliation(s)
- Mathias Paul
- Cologne UniversityDepartment of Chemistry, Organic Chemistry Greinstrasse 4 50939 Cologne Germany
| | - Panyapon Sudkaow
- Cologne UniversityDepartment of Chemistry, Organic Chemistry Greinstrasse 4 50939 Cologne Germany
| | - Alina Wessels
- Cologne UniversityDepartment of Chemistry, Organic Chemistry Greinstrasse 4 50939 Cologne Germany
| | - Nils E. Schlörer
- Cologne UniversityDepartment of Chemistry, Organic Chemistry Greinstrasse 4 50939 Cologne Germany
| | - Jörg‐M. Neudörfl
- Cologne UniversityDepartment of Chemistry, Organic Chemistry Greinstrasse 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Cologne UniversityDepartment of Chemistry, Organic Chemistry Greinstrasse 4 50939 Cologne Germany
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35
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Paul M, Sudkaow P, Wessels A, Schlörer NE, Neudörfl J, Berkessel A. Breslow‐Intermediate aromatischer N‐heterocyclischer Carbene (Benzimidazolin‐2‐ylidene, Thiazolin‐2‐ylidene). Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201801676] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Mathias Paul
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Panyapon Sudkaow
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Alina Wessels
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Nils E. Schlörer
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Jörg‐M. Neudörfl
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
| | - Albrecht Berkessel
- Universität zu KölnDepartment für ChemieOrganische Chemie Greinstraße 4 50939 Köln Deutschland
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36
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Surup F, Kuhnert E, Böhm A, Pendzialek T, Solga D, Wiebach V, Engler H, Berkessel A, Stadler M, Kalesse M. The Rickiols: 20-, 22-, and 24-membered Macrolides from the Ascomycete Hypoxylon rickii. Chemistry 2018; 24:2200-2213. [PMID: 29168908 DOI: 10.1002/chem.201704928] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Indexed: 11/10/2022]
Abstract
In preceding studies the neotropical ascomycete Hypoxylon rickii turned out to be a prolific source of new secondary metabolites, considering that we had obtained terpenoids with five different scaffolds along with a series of terphenyls. From the mycelial extracts of a 70 L scale fermentation of this strain we additionally isolated nine new macrolides (1-9) by RP-HPLC. The planar structures were elucidated by NMR spectroscopy complemented by HR-ESIMS. The relative configurations were assigned by J-based configuration analyses and confirmed by Kishi's Universal Database. Subsequently, the absolute configurations were assigned by Mosher's method using the shift analysis of a tetra-MTPA derivative. For rickiol A (1) and E (5) we observed transesterification of 20-membered ring structures to 22-membered isomers rickiol A2 (6) and E2 (7), and to 24-membered isomers rickiol A3 (8) and rickiol E3 (9), respectively. Cytotoxic effects and moderate antibiotic activity against Gram-positive bacteria were observed for 1-8 and 1-6 and 8, respectively. The total synthesis of rickiol E3 (9) established easier access to these compounds.
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Affiliation(s)
- Frank Surup
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany.,Partner site Hannover-Braunschweig, German Centre for Infection Research Association (DZIF), Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Eric Kuhnert
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Andreas Böhm
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany
| | - Tim Pendzialek
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany
| | - Danny Solga
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany
| | - Vincent Wiebach
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany.,Institut für Chemie, Technische Universität Berlin, Müller-Breslau-Straße 10, 10623, Berlin, Germany
| | - Hauke Engler
- Department of Chemistry, Organic Chemistry, Cologne University, Greinstraße 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, Cologne University, Greinstraße 4, 50939, Cologne, Germany
| | - Marc Stadler
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany.,Partner site Hannover-Braunschweig, German Centre for Infection Research Association (DZIF), Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Markus Kalesse
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Medicinal Chemistry, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany
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37
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Pal K, Heinsch A, Berkessel A, Koner AL. Differentiation of Folate-Receptor-Positive and -Negative Cells Using a Substrate-Mimicking Fluorescent Probe. Chemistry 2017; 23:15008-15011. [DOI: 10.1002/chem.201703305] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Indexed: 01/03/2023]
Affiliation(s)
- Kaushik Pal
- Department of Chemistry; Indian Institute of Science Education and Research Bhopal; Bhopal Bypass Road Bhauri Bhopal (MP)- 462066 India
| | - Angela Heinsch
- Department of Chemistry; University of Cologne; Greinstrasse 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry; University of Cologne; Greinstrasse 4 50939 Cologne Germany
| | - Apurba L. Koner
- Department of Chemistry; Indian Institute of Science Education and Research Bhopal; Bhopal Bypass Road Bhauri Bhopal (MP)- 462066 India
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38
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Sauermann N, Loup J, Kootz D, Yatham V, Berkessel A, Ackermann L. Triazolylidene Ligands Allow Cobalt-Catalyzed C–H/C–O Alkenylations at Ambient Temperature. SYNTHESIS-STUTTGART 2017. [DOI: 10.1055/s-0036-1590471] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Direct alkenylation through C–H/C–O cleavage was accomplished under mild reaction conditions by cobalt catalysts derived from novel triazolylidene ligands. The most effective ligand is characterized by sterically demanding substituents on the 1,4-N-atoms of the triazolylidene neighboring the carbene center. The C–H alkenylations proved viable with alkenyl acetates, carbamates, carbonates and phosphates. For acyclic electrophiles, diastereoconvergent C–O functionalizations were observed.
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Affiliation(s)
- Nicolas Sauermann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität
| | - Joachim Loup
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität
| | - Darius Kootz
- Department für Chemie, Organische Chemie, Universität zu Köln
| | - V. Yatham
- Department für Chemie, Organische Chemie, Universität zu Köln
| | | | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität
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39
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Berkessel A, Eröksüz S, Neudörfl J. Kinetic Resolution of 5-Substituted Oxazinones with Bifunctional Chiral Base/Squaramide Organocatalysts. Synlett 2017. [DOI: 10.1055/s-0036-1588852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
5-Substituted oxazinones provide N-protected β2-amino acid esters upon alcoholytic ring opening. Thus far, this access to enantiopure β2-amino acids has been restricted to the use of enzymes (hydrolases) as catalysts for the kinetic resolution of racemic 5-substituted oxazinones, and branched alkyl or ortho-substituted aryl groups on the substrate oxazinone’s 5-position were typically not tolerated. We herein report that certain bifunctional chiral base/squaramide organocatalysts, in particular those derived from cis-1,2-diaminocyclohexane or 9-amino-9-epi-quinine, allow the first organocatalytic kinetic resolution of this ‘difficult’ class of oxazinone substrates, affording N-protected β2-amino acid esters with selectivity factors up to 43.
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40
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Schäfer M, Peckelsen K, Paul M, Martens J, Oomens J, Berden G, Berkessel A, Meijer AJHM. Hydrogen Tunneling above Room Temperature Evidenced by Infrared Ion Spectroscopy. J Am Chem Soc 2017; 139:5779-5786. [PMID: 28282985 DOI: 10.1021/jacs.6b10348] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While hydrogen tunneling at elevated temperatures has, for instance, often been postulated in biochemical processes, spectroscopic proof is thus far limited to cryogenic conditions, under which thermal reactivity is negligible. We report spectroscopic evidence for H-tunneling in the gas phase at temperatures around 320-350 K observed in the isomerization reaction of a hydroxycarbene into an aldehyde. The charge-tagged carbene was generated in situ in a tandem mass spectrometer by decarboxylation of oxo[4-(trimethylammonio)phenyl]acetic acid upon collision induced dissociation. All ion structures involved are characterized by infrared ion spectroscopy and quantum chemical calculations. The charge-tagged phenylhydroxycarbene undergoes a 1,2-H-shift to the corresponding aldehyde with an half-life of about 10 s, evidenced by isomer-selective two-color (IR-IR) spectroscopy. In contrast, the deuterated (OD) carbene analogue showed much reduced 1,2-D-shift reactivity with an estimated half-life of at least 200 s under the experimental conditions, and provides clear evidence for hydrogen atom tunneling in the H-isotopologue. This is the first spectroscopic confirmation of hydrogen atom tunneling governing 1,2-H-shift reactions at noncryogenic temperatures, which is of broad significance for a range of (bio)chemical processes, including enzymatic transformations and organocatalysis.
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Affiliation(s)
- Mathias Schäfer
- Department of Chemistry, Organic Chemistry, University of Cologne , Greinstraße 4, 50939 Cologne, Germany
| | - Katrin Peckelsen
- Department of Chemistry, Organic Chemistry, University of Cologne , Greinstraße 4, 50939 Cologne, Germany
| | - Mathias Paul
- Department of Chemistry, Organic Chemistry, University of Cologne , Greinstraße 4, 50939 Cologne, Germany
| | - Jonathan Martens
- Radboud University , Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - Jos Oomens
- Radboud University , Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands.,Van't Hoff Institute for Molecular Sciences, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Giel Berden
- Radboud University , Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne , Greinstraße 4, 50939 Cologne, Germany
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41
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Heidlindemann M, Berkessel A, Gröger H. “Side-Product Catalysis”: Substrate Autoxidation as an Overlooked Side Reaction Generating a Co-Catalyst for Enhancing Asymmetric Aldol Reactions. ChemCatChem 2017. [DOI: 10.1002/cctc.201601530] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Marcel Heidlindemann
- Chair of Organic Chemistry I, Faculty of Chemistry; University of Bielefeld; Universitätsstraße 25 33615 Bielefeld Germany
| | - Albrecht Berkessel
- Department of Chemistry; University of Cologne; Greinstr. 4 50939 Köln Germany
| | - Harald Gröger
- Chair of Organic Chemistry I, Faculty of Chemistry; University of Bielefeld; Universitätsstraße 25 33615 Bielefeld Germany
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42
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Vailati Facchini S, Neudörfl JM, Pignataro L, Cettolin M, Gennari C, Berkessel A, Piarulli U. Synthesis of [Bis(hexamethylene)cyclopentadienone]iron Tricarbonyl and its Application to the Catalytic Reduction of C=O Bonds. ChemCatChem 2017. [DOI: 10.1002/cctc.201601591] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Sofia Vailati Facchini
- Dipartimento di Scienza e Alta Tecnologia; Università degli Studi dell'Insubria; Via Valleggio 11 22100 Como Italy
- Department für Chemie; Universität zu Köln; Greinstraße 4 50939 Köln Germany
| | | | - Luca Pignataro
- Dipartimento di Chimica; Università degli Studi di Milano; Via C. Golgi, 19 20133 Milano Italy
| | - Mattia Cettolin
- Dipartimento di Chimica; Università degli Studi di Milano; Via C. Golgi, 19 20133 Milano Italy
| | - Cesare Gennari
- Dipartimento di Chimica; Università degli Studi di Milano; Via C. Golgi, 19 20133 Milano Italy
| | - Albrecht Berkessel
- Department für Chemie; Universität zu Köln; Greinstraße 4 50939 Köln Germany
| | - Umberto Piarulli
- Dipartimento di Scienza e Alta Tecnologia; Università degli Studi dell'Insubria; Via Valleggio 11 22100 Como Italy
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43
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Hollóczki O, Berkessel A, Mars J, Mezger M, Wiebe A, Waldvogel SR, Kirchner B. The Catalytic Effect of Fluoroalcohol Mixtures Depends on Domain Formation. ACS Catal 2017. [DOI: 10.1021/acscatal.6b03090] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Oldamur Hollóczki
- Mulliken
Center for Theoretical Chemistry, University of Bonn, Beringstr. 4
+ 6, D-53115 Bonn, Germany
| | | | - Julian Mars
- Institute
of Physics, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Markus Mezger
- Institute
of Physics, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Anton Wiebe
- Institute
of Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg
10-14, 55128 Mainz, Germany
| | - Siegfried R. Waldvogel
- Institute
of Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg
10-14, 55128 Mainz, Germany
| | - Barbara Kirchner
- Mulliken
Center for Theoretical Chemistry, University of Bonn, Beringstr. 4
+ 6, D-53115 Bonn, Germany
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44
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Rulli G, Duangdee N, Hummel W, Berkessel A, Gröger H. First Tandem-Type One-Pot Process Combining Asymmetric Organo- and Biocatalytic Reactions in Aqueous Media Exemplified for the Enantioselective and Diastereoselective Synthesis of 1,3-Diols. European J Org Chem 2017. [DOI: 10.1002/ejoc.201600831] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Giuseppe Rulli
- Department of Chemistry and Pharmacy; University of Erlangen-Nürnberg; Henkestr. 42 91054 Erlangen Germany
| | - Nongnaphat Duangdee
- Department of Chemistry; University of Cologne; Greinstraße 4 50939 Cologne Germany
| | - Werner Hummel
- Institute of Molecular Enzyme Technology; Heinrich-Heine-University of Düsseldorf; Research Centre Jülich; Stetternicher Forst 52426 Jülich Germany
| | - Albrecht Berkessel
- Department of Chemistry; University of Cologne; Greinstraße 4 50939 Cologne Germany
| | - Harald Gröger
- Department of Chemistry and Pharmacy; University of Erlangen-Nürnberg; Henkestr. 42 91054 Erlangen Germany
- Faculty of Chemistry; Bielefeld University; Universitätsstr. 25 33615 Bielefeld Germany
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45
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Lansing M, Engler H, Leuther TM, Neudörfl JM, Berkessel A. Titaniumcis-1,2-Diaminocyclohexane Salalen Catalysts of Outstanding Activity and Enantioselectivity for the Asymmetric Epoxidation of Nonconjugated Terminal Olefins with Hydrogen Peroxide. ChemCatChem 2016. [DOI: 10.1002/cctc.201601154] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Markus Lansing
- Department of Chemistry, Organic Chemistry; Cologne University; Greinstrasse 4 50939 Cologne Germany
| | - Hauke Engler
- Department of Chemistry, Organic Chemistry; Cologne University; Greinstrasse 4 50939 Cologne Germany
| | - Tobias M. Leuther
- Department of Chemistry, Organic Chemistry; Cologne University; Greinstrasse 4 50939 Cologne Germany
| | - Jörg-M. Neudörfl
- Department of Chemistry, Organic Chemistry; Cologne University; Greinstrasse 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry; Cologne University; Greinstrasse 4 50939 Cologne Germany
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46
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Harnying W, Berkessel A, Neudörfl JM. Catalytic Prins Reaction Effected by Molecular Iodine in the Presence of Bis(trifluoromethanesulfonyl)imide Salts. SYNTHESIS-STUTTGART 2016. [DOI: 10.1055/s-0036-1588367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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47
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Bulut D, Duangdee N, Gröger H, Berkessel A, Hummel W. Screening, Molecular Cloning, and Biochemical Characterization of an Alcohol Dehydrogenase from Pichia pastoris Useful for the Kinetic Resolution of a Racemic β-Hydroxy-β-trifluoromethyl Ketone. Chembiochem 2016; 17:1349-58. [PMID: 27123855 DOI: 10.1002/cbic.201600101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Indexed: 12/28/2022]
Abstract
The stereoselective synthesis of chiral 1,3-diols with the aid of biocatalysts is an attractive tool in organic chemistry. Besides the reduction of diketones, an alternative approach consists of the stereoselective reduction of β-hydroxy ketones (aldols). Thus, we screened for an alcohol dehydrogenase (ADH) that would selectively reduce a β-hydroxy-β-trifluoromethyl ketone. One potential starting material for this process is readily available by aldol addition of acetone to 2,2,2-trifluoroacetophenone. Over 200 strains were screened, and only a few yeast strains showed stereoselective reduction activities. The enzyme responsible for the reduction of the β-hydroxy-β-trifluoromethyl ketone was identified after purification and subsequent MALDI-TOF mass spectrometric analysis. As a result, a new NADP(+) -dependent ADH from Pichia pastoris (PPADH) was identified and confirmed to be capable of stereospecific and diastereoselective reduction of the β-hydroxy-β-trifluoromethyl ketone to its corresponding 1,3-diol. The gene encoding PPADH was cloned and heterologously expressed in Escherichia coli BL21(DE3). To determine the influence of an N- or C-terminal His-tag fusion, three different recombinant plasmids were constructed. Interestingly, the variant with the N-terminal His-tag showed the highest activity; consequently, this variant was purified and characterized. Kinetic parameters and the dependency of activity on pH and temperature were determined. PPADH shows a substrate preference for the reduction of linear and branched aliphatic aldehydes. Surprisingly, the enzyme shows no comparable activity towards ketones other than the β-hydroxy-β-trifluoromethyl ketone.
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Affiliation(s)
- Dalia Bulut
- Institute of Molecular Enzyme Technology, Heinrich Heine University of Düsseldorf, Research Centre Jülich, Wilhelm-Johnen-Strasse, 52426, Jülich, Germany.,Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Nongnaphat Duangdee
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Köln, Germany
| | - Harald Gröger
- Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Cologne University, Greinstrasse 4, 50939, Köln, Germany
| | - Werner Hummel
- Institute of Molecular Enzyme Technology, Heinrich Heine University of Düsseldorf, Research Centre Jülich, Wilhelm-Johnen-Strasse, 52426, Jülich, Germany. .,Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615, Bielefeld, Germany.
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48
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Abstract
Breslow intermediates, first postulated in 1958, are pivotal intermediates in carbene-catalyzed umpolung. Attempts to isolate and characterize these fleeting amino enol species first met with success in 2012 when we found that saturated bis-Dipp/Mes imidazolidinylidenes readily form isolable, though reactive diamino enols with aldehydes and enals. In contrast, triazolylidenes, upon stoichiometric reaction with aldehydes, gave exclusively the keto tautomer, and no isolable enol. Herein, we present the synthesis of the "missing" keto tautomers of imidazolidinylidene-derived diamino enols, and computational thermodynamic data for 15 enol-ketone pairs derived from various carbenes/aldehydes. Electron-withdrawing substituents on the aldehyde favor enol formation, the same holds for N,N'-Dipp [2,6-di(2-propyl)phenyl] and N,N'-Mes [2,4,6-trimethylphenyl] substitution on the carbene component. The latter effect rests on stabilization of the diamino enol tautomer by Dipp substitution, and could be attributed to dispersive interaction of the 2-propyl groups with the enol moiety. For three enol-ketone pairs, equilibration of the thermodynamically disfavored tautomer was attempted with acids and bases but could not be effected, indicating kinetic inhibition of proton transfer.
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Affiliation(s)
- Mathias Paul
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Martin Breugst
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Jörg-Martin Neudörfl
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Raghavan B Sunoj
- Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
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49
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Yatham VR, Harnying W, Kootz D, Neudörfl JM, Schlörer NE, Berkessel A. 1,4-Bis-Dipp/Mes-1,2,4-Triazolylidenes: Carbene Catalysts That Efficiently Overcome Steric Hindrance in the Redox Esterification of α- and β-Substituted α,β-Enals. J Am Chem Soc 2016; 138:2670-7. [PMID: 26797403 DOI: 10.1021/jacs.5b11796] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
As reported by Scheidt and Bode in 2005, sterically nonencumbered α,β-enals are readily converted to saturated esters in the presence of alcohols and N-heterocyclic carbene catalysts, e.g., benzimidazolylidenes or triazolylidenes. However, substituents at the α- or β-position of the α,β-enal substrate are typically not tolerated, thus severely limiting the substrate spectrum. On the basis of our earlier mechanistic studies, a set of N-Mes- or N-Dipp-substituted 1,2,4-triazolium salts were synthesized and evaluated as (pre)catalysts in the redox esterification of various α- or β-substituted enals. In particular the 1,4-bis-Mes/Dipp-1,2,4-triazolylidenes overcome the above limitations and efficiently catalyze the redox esterification of a whole series of α/β-substituted enals hitherto not amenable to NHC-catalyzed transformations. The synthetic value of 1,4-bis-Mes/Dipp-1,2,4-triazolylidenes is further demonstrated by the one-step bicyclization of 10-oxocitral to (racemic) nepetalactone in diastereomerically pure form.
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Affiliation(s)
- Veera Reddy Yatham
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Wacharee Harnying
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Darius Kootz
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Jörg-M Neudörfl
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Nils E Schlörer
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry (Organic Chemistry), University of Cologne , Greinstrasse 4, 50939 Cologne, Germany
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50
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Gianolio E, Mohan R, Berkessel A. EnantiopureN-Benzyloxycarbonyl-β2-amino Acid Allyl Esters from Racemic β-Lactams by Dynamic Kinetic Resolution usingCandida antarcticaLipase B. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500820] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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