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Bao H, Bravo-Altamirano K, Buchan Z, Cabrera PJ, Ryan SJ, Roth JJ, Sartillo-Piscil F, Sawai Y, Tambar UK, Zarate C. Academic-Industrial Collaborations: Merging Paths to Thrive. Org Lett 2024; 26:2669-2671. [PMID: 38606471 DOI: 10.1021/acs.orglett.4c01107] [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: 04/13/2024]
Affiliation(s)
- Hongli Bao
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China
| | - Karla Bravo-Altamirano
- Pfizer Worldwide Research and Development Medicine, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Zachary Buchan
- Discovery Chemistry, Small Molecule Discovery and Development, Corteva Agrisciences, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Pablo J Cabrera
- Chemical Research & DevelopmentPfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Sarah J Ryan
- Nufarm Limited, Pipe Road, Laverton North, VIC 3026, Australia
| | - Joshua J Roth
- Discovery Chemistry, Small Molecule Discovery and Development, Corteva Agrisciences, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Fernando Sartillo-Piscil
- Centro de Investigación de la Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla (BUAP), 14 Sur Esq. San Claudio, Col. San Manuel, 72570 Puebla, México
| | - Yasuhiro Sawai
- Synthetic Molecule Process Development, Pharmaceutical Sciences, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Cayetana Zarate
- Johnson & Johnson Innovative Medicine, Chemical Process R&D, Cilag AG, Hochstrasse 201, 8200 Schaffhausen, Switzerland
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Manna MS, Yoo SY, Sharique M, Choi H, Pudasaini B, Baik MH, Tambar UK. Copper-Catalyzed Regiodivergent Internal Allylic Alkylations. Angew Chem Int Ed Engl 2023; 62:e202304848. [PMID: 37327025 PMCID: PMC10528884 DOI: 10.1002/anie.202304848] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/05/2023] [Accepted: 06/12/2023] [Indexed: 06/17/2023]
Abstract
We report a copper-catalyzed, regioselective, and stereospecific alkylation of unbiased internal allylic carbonates with functionalized alkyl and aryl Grignard reagents. The reactions exhibit high stereospecificity and regioselectivity for either SN 2 or SN 2' products under two sets of copper-catalyzed conditions, which enables the preparation of a broad range of products with E-alkene selectivity. Density functional theory calculations reveal the origins of the regioselectivity based on the different behaviors of homo- and heterocuprates.
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Affiliation(s)
- Madhu Sudan Manna
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Seok Yeol Yoo
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Mohammed Sharique
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Hyoju Choi
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Bimal Pudasaini
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Mu-Hyun Baik
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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3
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Abstract
Sulfonyl fluorides have emerged as powerful tools in chemical biology for the selective labelling of proteins. A photocatalytic method is described for the conversion of aryl diazonium salts to aryl sulfonyl fluorides. The diazonium substrates are easily obtained in one step from functionalized anilines. We present the optimization of this mild method for the synthesis of sulfonyl fluorides, the scope of the transformation with a series of functionalized diazonium salts, and we discuss photophysical measurements that provide detailed information about the mechanism of the photochemical process.
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Affiliation(s)
- Cooper A. Vincent
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, United States
| | - Alexia Ripak
- Université Catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348, Louvain-la-Neuve, Belgium
| | - Ludovic Troian-Gautier
- Université Catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348, Louvain-la-Neuve, Belgium
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, United States
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4
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Abstract
Sulfonyl fluorides are highly versatile molecules for click chemistry that have found applications in many areas of chemistry and biology. Recent chemical approaches have focused on the synthesis of alkyl sulfonyl fluorides from readily available starting materials. Here, we report a photocatalytic synthesis of alkyl sulfonyl fluorides from organotrifluoroborates and boronic acid pinacol esters, which are building blocks commonly employed by medicinal chemists in the synthesis of bioactive molecules. Steady-state and time-resolved spectroscopy have confirmed that the absorption of photons by the acridinium catalysts leads to the oxidation of the organotrifluoroborate substrates. The reaction exhibits broad functional group tolerance, which can be attributed to the mild activation with visible light. Importantly, this general approach provides easy access to primary, secondary, and tertiary alkyl sulfonyl fluorides.
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Affiliation(s)
- Cooper A Vincent
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, United States
| | - Maria Irina Chiriac
- Department of Discovery Chemistry, Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Ludovic Troian-Gautier
- Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Institut de la Matierè Condensée et des Nanosciences (IMCN), 1348 Louvain-la-Neuve, Belgium
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, United States
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Ripak A, De Kreijger S, Sampaio RN, Vincent CA, Cauët É, Jabin I, Tambar UK, Elias B, Troian-Gautier L. Photosensitized Activation of Diazonium Derivatives for C-B Bond Formation. Chem Catal 2023; 3:100490. [PMID: 36936750 PMCID: PMC10022585 DOI: 10.1016/j.checat.2022.100490] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Aryl diazonium salts are ubiquitous building blocks in chemistry, as they are useful radical precursors in organic synthesis as well as for the functionalization of solid materials. They can be reduced electrochemically or through a photo-induced electron transfer reaction. Here we provide a detailed picture of the ground and excited-state reactivity of a series of 9 rare and earth abundant photosensitizers with 13 aryl diazonium salts, which also included 3 macrocyclic calix[4]arene tetradiazonium salts. Nanosecond transient absorption spectroscopy confirmed the occurrence of excited-state electron transfer and was used to quantify cage-escape yields, i.e. the efficiency with which the formed radicals separate and escape the solvent cage. Cage-escape yields were large; increased when the driving force for photo-induced electron transfer increased and also tracked with the C-N2 + bond cleavage propensity, amongst others. A photo-induced borylation reaction was then investigated with all the photosensitizers and proceeded with yields between 9 and 74%.
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Affiliation(s)
- Alexia Ripak
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Simon De Kreijger
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Renato N. Sampaio
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, United States
| | - Cooper A. Vincent
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Émilie Cauët
- Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (CP 160/09), Université libre de Bruxelles (ULB), 50 av. F. D. Roosevelt, CP160/09, B-1050 Brussels, Belgium
| | - Ivan Jabin
- Laboratoire de Chimie Organique, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50, CP160/06, B-1050 Brussels, Belgium
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Benjamin Elias
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Ludovic Troian-Gautier
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
- Lead contact
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Yetra SR, Schmitt N, Tambar UK. Catalytic photochemical enantioselective α-alkylation with pyridinium salts. Chem Sci 2023; 14:586-592. [PMID: 36741522 PMCID: PMC9847668 DOI: 10.1039/d2sc05654b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 10/11/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022] Open
Abstract
We have developed a chiral amine catalyzed enantioselective α-alkylation of aldehydes with amino acid derived pyridinium salts as alkylating reagents. The reaction proceeds in the presence of visible light and in the absence of a photocatalyst via a light activated charge-transfer complex. We apply this photochemical stereoconvergent process to the total synthesis of the lignan natural products (-)-enterolactone and (-)-enterodiol. Mechanistic studies support the ground-state complexation of the reactive components followed by divergent charge-transfer processes involving catalyst-controlled radical chain and in-cage radical combination steps.
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Affiliation(s)
- Santhivardhana Reddy Yetra
- Department of Biochemistry, The University of Texas Southwestern Medical Center5323 Harry Hines BoulevardDallasTexas 75390-9038USA
| | - Nathan Schmitt
- Department of Biochemistry, The University of Texas Southwestern Medical Center5323 Harry Hines BoulevardDallasTexas 75390-9038USA
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center5323 Harry Hines BoulevardDallasTexas 75390-9038USA
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Rodriguez M, Kannangara A, Chlebowicz J, Akella R, He H, Tambar UK, Goldsmith EJ. Synthesis and Structural Characterization of Novel Trihalo-sulfone Inhibitors of WNK1. ACS Med Chem Lett 2022; 13:1678-1684. [PMID: 36262391 PMCID: PMC9575160 DOI: 10.1021/acsmedchemlett.2c00216] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/14/2022] [Indexed: 11/29/2022] Open
Abstract
With No lysine (K) [WNK] kinases are structurally unique serine/threonine protein kinases that have therapeutic potential for blood pressure regulation and cancer. A novel class of trihalo-sulfone compounds was identified by high-throughput screening. Trihalo-sulfone 1 emerged as an effective inhibitor of WNK1 with an IC50 value of 1.6 μM. Herein, we define chemical features necessary for inhibition of WNK1 using chemical synthesis and X-ray crystallography. Analogues that probed the role of specific functional groups to the inhibitory activity were synthesized. X-ray structures of trihalo-sulfone 1 and a second trihalo-sulfone 23 bound to WNK1 revealed active site binding to two of the three previously defined canonical inhibitor binding pockets as well as a novel binding site for the trihalo-sulfone moiety. The elucidation of these novel interaction sites may allow for the strategic design of even more selective and potent WNK inhibitors.
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Affiliation(s)
- Melanie Rodriguez
- Department
of Biochemistry, The University of Texas
Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Ashari Kannangara
- Department
of Biophysics, The University of Texas Southwestern
Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, United States
| | - Julita Chlebowicz
- Department
of Biophysics, The University of Texas Southwestern
Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, United States
| | - Radha Akella
- Department
of Biophysics, The University of Texas Southwestern
Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, United States
| | - Haixia He
- Department
of Biophysics, The University of Texas Southwestern
Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, United States
| | - Uttam K. Tambar
- Department
of Biochemistry, The University of Texas
Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Elizabeth J. Goldsmith
- Department
of Biophysics, The University of Texas Southwestern
Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, United States
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8
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Tagal V, Tambar UK, Roth MG, Minna JD. Abstract B037: Characterizing and targeting polyaneuploid/polyploid giant cancer cells (PACCs/PGCCs). Cancer Res 2022. [DOI: 10.1158/1538-7445.evodyn22-b037] [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: 11/16/2022]
Abstract
Abstract
Polyaneuploid/polyploid giant cancer cells (PACCs/PGCCs) are common in tumors and have been tightly linked with tumor heterogeneity, resistance to cancer therapy, tumor relapse, metastasis, malignancy, immunosuppression, modulation of the tumor microenvironment and cancer stem cells. The abundance of PACCs/PGCCs is markedly higher in high-grade malignant tumors than in low-grade tumors, in the metastatic foci than in the primary tumor, and in relapsing tumors post-chemotherapy than in tumors before therapy. Immunosuppressive proteins including programmed death-ligand 1 (PD-L1) were also found to be overexpressed in these cells. Such cells are known to escape from cytotoxicity induced by major anti-cancer agents including taxanes, vinca alkaloids and platinum-based chemotherapies. Therefore, they are responsible of contributing to a microenvironment advantageous for tumor growth and survival. However, the molecular mechanisms that cause these cells to form were not yet known. PACCs/PGCCs can repopulate in vitro as they generate tumors when inoculated into mice. Their daughter cells acquire a mesenchymal phenotype, which is a key transformation for cancer development, progression and metastasis. Emerging evidence has demonstrated PACCs/PGCCs arise in lung cancer, cervical carcinoma, ovarian cancer, prostate cancer, glioblastoma, colorectal cancer and breast cancer. Therefore, revealing the molecular events that cause PACCs/PGCCs to form could lead to clinically relevant approaches for treating recurrent and metastatic disease. With our studies, we discovered that Aurora kinases and Cyclin-dependent kinases 4/6 (CDK4/6) were two separate synergistic determinants of distinct switches from the proliferative cell cycle to polyploid growth state in lung cancer cell lines. When Aurora kinases are inhibited together, cancer cells uniformly grow into multinucleated PACCs/PGCCs whereas inactivation of CDK4/6 forms mononucleated PACCs/PGCCs. These cells adopt an endoreplication in which the genome replicates, mitosis is omitted and cells grow in size. Consequently, such cells continue to safely grow in the presence of anti-cancer agents. These PGCCs can reenter the proliferative cell cycle and grow in cell number when the treatment is terminated. Based upon our results, we were funded to find chemical inhibitors to target PACCs/PGCCs. We have conducted a high-throughput screen of 332,500 chemicals of the UT Southwestern chemical library to identify those that were toxic to our representative cell line model, but not to cells with normal ploidy, including immortalized normal human bronchial epithelial cells (HBECs). Currently, in our research program, we have two major projects, which includes: (1) A complete biological and mechanistic characterization of PACCs/PGCCs in cancer initiation, progression, metastasis and drug resistance, and (2) development of inhibitors to target PACCs/PGCCs as drug candidates for cancer therapies. To the best of our knowledge, ours are the first studies to describe the responsible genes involved in the formation of PACCs/PGCCs.
Citation Format: Vural Tagal, Uttam K. Tambar, Michael G. Roth, John D. Minna. Characterizing and targeting polyaneuploid/polyploid giant cancer cells (PACCs/PGCCs) [abstract]. In: Proceedings of the AACR Special Conference on the Evolutionary Dynamics in Carcinogenesis and Response to Therapy; 2022 Mar 14-17. Philadelphia (PA): AACR; Cancer Res 2022;82(10 Suppl):Abstract nr B037.
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Nair VN, Tambar UK. Catalytic rearrangements of onium ylides in aromatic systems. Org Biomol Chem 2022; 20:3427-3439. [PMID: 35388871 PMCID: PMC10124236 DOI: 10.1039/d2ob00218c] [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: 11/21/2022]
Abstract
Onium ylides are reactive intermediates that undergo versatile chemical transformations to give structurally interesting compounds. Rearrangement reactions of onium ylides are of great importance to synthetic organic chemists, as they provide efficient methods for C-C bond formations as well as installation of new stereogenic centers in molecules. Traditionally, onium ylides have been shown to undergo two types of rearrangements, namely, [2,3]- and [1,2]-rearrangements. In recent years, there have been tremendous developments in the field of metal-catalyzed onium ylide rearrangements through catalytic generation of ylide intermediates from diazocompounds. Several examples of selective catalytic onium ylide rearrangements involving sulfonium, oxonium, ammonium, as well as iodonium ylides have been developed over the years especially in allylic and propargylic systems. However, when the π-system that takes part in the rearrangement is part of an aromatic ring, the selectivity for rearrangements of reactive onium ylides is more challenging. In this review, we discuss recent advances in catalyst control of onium ylide rearrangements of aromatic systems.
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Affiliation(s)
- Vaishnavi N Nair
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA.
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA.
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10
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Nair VN, Tambar UK. Synthesis of amines via coupling of imines and alkylarenes. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.153788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Oliver GA, Loch MN, Augustin AU, Steinbach P, Sharique M, Tambar UK, Jones PG, Bannwarth C, Werz DB. Cycloadditions of Donor–Acceptor Cyclopropanes and ‐butanes using S=N‐Containing Reagents: Access to Cyclic Sulfinamides, Sulfonamides, and Sulfinamidines. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106596] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Gwyndaf A. Oliver
- Technische Universität Braunschweig Institute of Organic Chemistry Hagenring 30 38106 Braunschweig Germany
| | - Maximilian N. Loch
- Technische Universität Braunschweig Institute of Organic Chemistry Hagenring 30 38106 Braunschweig Germany
| | - André U. Augustin
- Technische Universität Braunschweig Institute of Organic Chemistry Hagenring 30 38106 Braunschweig Germany
| | - Pit Steinbach
- Institute of Physical Chemistry RWTH Aachen University Melatener Str. 20 52056 Aachen Germany
| | - Mohammed Sharique
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Uttam K. Tambar
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Peter G. Jones
- Technische Universität Braunschweig Institute of Inorganic and Analytical Chemistry Hagenring 30 38106 Braunschweig Germany
| | - Christoph Bannwarth
- Institute of Physical Chemistry RWTH Aachen University Melatener Str. 20 52056 Aachen Germany
| | - Daniel B. Werz
- Technische Universität Braunschweig Institute of Organic Chemistry Hagenring 30 38106 Braunschweig Germany
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Kakde BN, Capota E, Kohler JJ, Tambar UK. Synthesis of Cell-Permeable N-Acetylhexosamine 1-Phosphates. J Org Chem 2021; 86:18257-18264. [PMID: 34618463 DOI: 10.1021/acs.joc.1c01781] [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: 11/29/2022]
Abstract
We recently reported the incorporation of diazirine photo-cross-linkers onto the O-GlcNAc posttranslational modification in mammalian cells, enabling the identification of binding partners of O-GlcNAcylated proteins. Unfortunately, the syntheses of the diazirine-functionalized substrates have exhibited inconsistent yields. We report a robust and stereoselective synthesis of cell-permeable GlcNAc-1-phosphate esters based on the use of commercially available bis(diisopropylamino)chlorophosphine. We demonstrate this approach for two diazirine-containing GlcNAc analogues, and we report the cellular incorporation of these compounds into glycoconjugates to support photo-cross-linking applications.
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Affiliation(s)
- Badrinath N Kakde
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Emanuela Capota
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Jennifer J Kohler
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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13
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Oliver GA, Loch MN, Augustin AU, Steinbach P, Sharique M, Tambar UK, Jones PG, Bannwarth C, Werz DB. Cycloadditions of Donor-Acceptor Cyclopropanes and -butanes using S=N-Containing Reagents: Access to Cyclic Sulfinamides, Sulfonamides, and Sulfinamidines. Angew Chem Int Ed Engl 2021; 60:25825-25831. [PMID: 34499800 PMCID: PMC9298015 DOI: 10.1002/anie.202106596] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [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: 05/17/2021] [Revised: 09/08/2021] [Indexed: 11/09/2022]
Abstract
We present (3+2)‐ and (4+2)‐cycloadditions of donor–acceptor (D–A) cyclopropanes and cyclobutanes with N‐sulfinylamines and a sulfur diimide, along with a one‐pot, two‐step strategy for the formal insertion of HNSO2 into D–A cyclopropanes. These are rare examples of cycloadditions with D–A cyclopropanes and cyclobutanes whereby the 2π component consists of two different heteroatoms, thus leading to five‐ and six‐membered rings containing adjacent heteroatoms.
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Affiliation(s)
- Gwyndaf A Oliver
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106, Braunschweig, Germany
| | - Maximilian N Loch
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106, Braunschweig, Germany
| | - André U Augustin
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106, Braunschweig, Germany
| | - Pit Steinbach
- Institute of Physical Chemistry, RWTH Aachen University, Melatener Str. 20, 52056, Aachen, Germany
| | - Mohammed Sharique
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Peter G Jones
- Technische Universität Braunschweig, Institute of Inorganic and Analytical Chemistry, Hagenring 30, 38106, Braunschweig, Germany
| | - Christoph Bannwarth
- Institute of Physical Chemistry, RWTH Aachen University, Melatener Str. 20, 52056, Aachen, Germany
| | - Daniel B Werz
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106, Braunschweig, Germany
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14
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Gartman JA, Tambar UK. Synthetic Studies of the Rubellin Natural Products: Development of a Stereoselective Strategy and Total Synthesis of (+)-Rubellin C. J Org Chem 2021; 86:11237-11262. [PMID: 34288689 DOI: 10.1021/acs.joc.1c00920] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This manuscript describes our studies of the class of natural products known as the rubellins, culminating in the total synthesis of (+)-rubellin C. These anthraquinone-based natural products contain a variety of stereochemical and architectural motifs, including a 6-5-6-fused ring system, 5 stereogenic centers, and a central quaternary center. Herein, we report our development of a strategy to target the stereochemically dense core and anthraquinone nucleus, including approaches such as a bifunctional allylboron and vinyl triflate reagent, an anthraquinone benzylic metalation strategy, and a late-stage anthraquinone introduction strategy. Our studies culminate in a successful route to highly functionalized anthraquinone-based natural product scaffolds and a stereoselective total synthesis of (+)-rubellin C. These strategies and outcomes will aid in synthetic planning toward anthraquinone-based natural products of high interest.
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Affiliation(s)
- Jackson A Gartman
- Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K Tambar
- Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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15
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Nair VN, Kojasoy V, Laconsay CJ, Kong WY, Tantillo DJ, Tambar UK. Catalyst-Controlled Regiodivergence in Rearrangements of Indole-Based Onium Ylides. J Am Chem Soc 2021; 143:9016-9025. [PMID: 34124896 PMCID: PMC8650141 DOI: 10.1021/jacs.1c00283] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We have developed catalyst-controlled regiodivergent rearrangements of onium-ylides derived from indole substrates. Oxonium ylides formed in situ from substituted indoles selectively undergo [2,3]- and [1,2]-rearrangements in the presence of a rhodium and a copper catalyst, respectively. The combined experimental and density functional theory (DFT) computational studies indicate divergent mechanistic pathways involving a metal-free ylide in the rhodium catalyzed reaction favoring [2,3]-rearrangement, and a metal-coordinated ion-pair in the copper catalyzed [1,2]-rearrangement that recombines in the solvent-cage. The application of our methodology was demonstrated in the first total synthesis of the indole alkaloid (±)-sorazolon B, which enabled the stereochemical reassignment of the natural product. Further functional group transformations of the rearrangement products to generate valuable synthetic intermediates were also demonstrated.
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Affiliation(s)
- Vaishnavi N Nair
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Volga Kojasoy
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Croix J Laconsay
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Wang Yeuk Kong
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Dean J Tantillo
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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16
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Affiliation(s)
- Mohammed Sharique
- Department of Biochemistry University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas 75390 Texas United States
| | - Uttam K. Tambar
- Department of Biochemistry University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas 75390 Texas United States
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17
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Abstract
The rubellins are a family of stereochemically complex anthraquinoid heterodimers containing an unprecedented chemical scaffold. Although the rubellins have been known for over three decades, no total synthesis has been achieved since their discovery. Their topology is characterized by a 6-5-6 fused ring system, five neighboring stereocenters including a quaternary center all in a convoluted core, and an anthraquinone nucleus. The rubellin architecture has been shown to inhibit and reverse the aggregation of tau protein, a therapeutically relevant target for Alzheimer's disease. Herein, we describe the first stereoselective synthesis of a member of the family, (+)-rubellin C, in 16 steps. Strategic disconnections allow expedient construction of stereochemical and topological intricacy in a short sequence of borylative and transition metal-catalyzed steps.
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Affiliation(s)
- Jackson A Gartman
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K Tambar
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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18
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Abstract
The venerable Hauser–Kraus annulation is an effective and convergent method for generating oxygenated polycyclic aromatic compounds. Despite its application in complex molecule synthesis, the harsh and strongly basic conditions can limit its utility in more functionalized molecular settings. We have developed the first catalytic Hauser–Kraus annulation based on N-heterocyclic carbene catalysis that proceeds under milder conditions. We demonstrate the scope of the transformation in the presence of several functional groups. We also propose a concerted mechanism for the annulation that proceeds through a non-canonical Breslow intermediate. The venerable Hauser–Kraus annulation is an effective and convergent method for generating oxygenated polycyclic aromatic compounds. A catalytic Hauser–Kraus annulation has been developed based on N-heterocyclic carbene catalysis.![]()
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Affiliation(s)
- Mohammed Sharique
- The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas Texas 75390-9038 USA
| | - Uttam K Tambar
- The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas Texas 75390-9038 USA
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19
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Xu B, Troian-Gautier L, Dykstra R, Martin R, Gutierrez O, Tambar UK. Photocatalyzed Diastereoselective Isomerization of Cinnamyl Chlorides to Cyclopropanes. J Am Chem Soc 2020; 142:6206-6215. [PMID: 32129997 PMCID: PMC7224234 DOI: 10.1021/jacs.0c00147] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Endergonic isomerizations are thermodynamically unfavored processes that are difficult to realize under thermal conditions. We report a photocatalytic and diastereoselective isomerization of acyclic cinnamyl chlorides to strained cyclopropanes. Quantum mechanical calculations (uM06-2X and DLPNO), including TD-DFT calculations, and experimental studies provide evidence for the energy transfer from an iridium photocatalyst to the allylic chloride substrate followed by C-Cl homolytic cleavage. Subsequent Cl• radical migration forms a localized triplet 1,3-diradical intermediate that, after intersystem crossing, undergoes ring-closing to form the desired product. The mild reaction conditions are compatible with a broad range of functional groups to generate chlorocyclopropanes in high yields and diastereoselectivities. A more efficient process is developed by addition of a catalytic amount of a nickel complex, and we propose a novel role for this cocatalyst to recycle an allyl chloride byproduct generated in the course of the reaction. The reaction is also shown to be stereoconvergent, as an E/Z mixture of cinnamyl chlorides furnish the anti-chlorocyclopropane product in high diastereoselectivity. We anticipate that the use of a visible light activated photocatalyst to transform substrates in combination with a transition metal catalyst to recycle byproducts back into the catalytic cycle will provide unique opportunities for the discovery of new reactivity.
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Affiliation(s)
- Bin Xu
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Ludovic Troian-Gautier
- Laboratoire de Chimie Organique, Université libre de Bruxelles (ULB), CP 160/06, 50 avenue F.D. Roosevelt, 1050 Brussels, Belgium
| | - Ryan Dykstra
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Robert Martin
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Osvaldo Gutierrez
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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20
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Krycer JR, Quek LE, Francis D, Fazakerley DJ, Elkington SD, Diaz-Vegas A, Cooke KC, Weiss FC, Duan X, Kurdyukov S, Zhou PX, Tambar UK, Hirayama A, Ikeda S, Kamei Y, Soga T, Cooney GJ, James DE. Lactate production is a prioritized feature of adipocyte metabolism. J Biol Chem 2020; 295:83-98. [PMID: 31690627 PMCID: PMC6952601 DOI: 10.1074/jbc.ra119.011178] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Adipose tissue is essential for whole-body glucose homeostasis, with a primary role in lipid storage. It has been previously observed that lactate production is also an important metabolic feature of adipocytes, but its relationship to adipose and whole-body glucose disposal remains unclear. Therefore, using a combination of metabolic labeling techniques, here we closely examined lactate production of cultured and primary mammalian adipocytes. Insulin treatment increased glucose uptake and conversion to lactate, with the latter responding more to insulin than did other metabolic fates of glucose. However, lactate production did not just serve as a mechanism to dispose of excess glucose, because we also observed that lactate production in adipocytes did not solely depend on glucose availability and even occurred independently of glucose metabolism. This suggests that lactate production is prioritized in adipocytes. Furthermore, knocking down lactate dehydrogenase specifically in the fat body of Drosophila flies lowered circulating lactate and improved whole-body glucose disposal. These results emphasize that lactate production is an additional metabolic role of adipose tissue beyond lipid storage and release.
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Affiliation(s)
- James R Krycer
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Lake-Ee Quek
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia; School of Mathematics and Statistics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Deanne Francis
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Daniel J Fazakerley
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia; Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, United Kingdom
| | - Sarah D Elkington
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Alexis Diaz-Vegas
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kristen C Cooke
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Fiona C Weiss
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Xiaowen Duan
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Sergey Kurdyukov
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Ping-Xin Zhou
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038; School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan 453003, China
| | - Uttam K Tambar
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038
| | - Akiyoshi Hirayama
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED), 1-7-1 Otemachi, Chiyoda-Ku, Tokyo 100-0004, Japan
| | - Satsuki Ikeda
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Yushi Kamei
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED), 1-7-1 Otemachi, Chiyoda-Ku, Tokyo 100-0004, Japan
| | - Gregory J Cooney
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia; Sydney Medical School, The University of Sydney, Sydney, New South Wales 2006, Australia.
| | - David E James
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia; Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia; Sydney Medical School, The University of Sydney, Sydney, New South Wales 2006, Australia.
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21
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Abstract
The direct conversion of C-H bonds into new C-C bonds represents a powerful approach to generate complex molecules from simple starting materials. However, a general and controllable method for the sequential conversion of a methyl group into a fully substituted carbon center remains a challenge. We report a new method for the selective and sequential replacement of three C-H bonds at the allylic position of propylene and other simple terminal alkenes with different carbon groups derived from Grignard reagents. A copper catalyst and electron-rich biaryl phosphine ligand facilitate the formation of allylic alkylation products in high branch selectivity. We also present conditions for the generation of enantioenriched allylic alkylation products in the presence of catalytic copper and a chiral phosphine ligand. With this approach, diverse and complex products with substituted carbon centers can be generated from simple and abundant feedstock chemicals.
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Affiliation(s)
- Ling Qin
- Department of Biochemistry , The University of Texas Southwestern Medical Center , 5323 Harry Hines Boulevard , Dallas , Texas 75390-9038 , United States
| | - Mohammed Sharique
- Department of Biochemistry , The University of Texas Southwestern Medical Center , 5323 Harry Hines Boulevard , Dallas , Texas 75390-9038 , United States
| | - Uttam K Tambar
- Department of Biochemistry , The University of Texas Southwestern Medical Center , 5323 Harry Hines Boulevard , Dallas , Texas 75390-9038 , United States
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22
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Abstract
The allylation reaction is a highly versatile transformation in chemical synthesis. While many elegant direct C(sp2)-H allylation reactions have been developed, the direct allylation of unactivated C(sp3)-H bonds is underdeveloped. By applying photoredox catalysis and a [1,5]-HAT process, herein we report a direct allylation of unactivated C(sp3)‒H bonds. This photocatalyzed transformation is tolerant of several functional groups in the amide and allylic chloride substrates. Various allyl-substituted amide products were obtained with good yields and high δ-selectivity.
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Affiliation(s)
- Bin Xu
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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23
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Nash A, Qi X, Maity P, Owens K, Tambar UK. Development of the Vinylogous Pictet-Spengler Cyclization and Total Synthesis of (±)-Lundurine A. Angew Chem Int Ed Engl 2018; 57:6888-6891. [PMID: 29663602 PMCID: PMC6392010 DOI: 10.1002/anie.201803702] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Indexed: 11/07/2022]
Abstract
A novel vinylogous Pictet-Spengler cyclization has been developed for the generation of indole-annulated medium-sized rings. The method enables the synthesis of tetrahydroazocinoindoles with a fully substituted carbon center, a prevalent structural motif in many biologically active alkaloids. The strategy has been applied to the total synthesis of (±)-lundurine A.
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Affiliation(s)
- Aaron Nash
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Xiangbing Qi
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Pradip Maity
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Kyle Owens
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
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24
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Nash A, Qi X, Maity P, Owens K, Tambar UK. Development of the Vinylogous Pictet–Spengler Cyclization and Total Synthesis of (±)‐Lundurine A. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201803702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Aaron Nash
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Xiangbing Qi
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Pradip Maity
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Kyle Owens
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Uttam K. Tambar
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
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25
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Abstract
The asymmetric allylic functionalization of unactivated internal alkenes is an emerging strategy for the conversion of simple unsaturated starting materials into a diverse range of enantioenriched products. This Perspective summarizes the development of reactions wherein a chiral catalyst facilitates the intermolecular stereoselective reaction between an achiral unactivated internal alkene and a reagent.
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Affiliation(s)
- Liela Bayeh
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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26
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Souza RF, Bayeh L, Spechler SJ, Tambar UK, Bruick RK. A new paradigm for GERD pathogenesis. Not acid injury, but cytokine-mediated inflammation driven by HIF-2α: a potential role for targeting HIF-2α to prevent and treat reflux esophagitis. Curr Opin Pharmacol 2017; 37:93-99. [PMID: 29112883 DOI: 10.1016/j.coph.2017.10.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 12/12/2022]
Abstract
Traditionally, reflux esophagitis was assumed to develop as a caustic, chemical injury inflicted by refluxed acid. Recently, however, studies in rats and humans suggest that reflux esophagitis develops as a cytokine-mediated inflammatory injury, with hypoxia inducible factor (HIF)-2α playing a major role. In response to the reflux of acid and bile, HIF-2α in esophageal epithelial cells becomes stabilized, thereby increasing production of pro-inflammatory cytokines that attract T lymphocytes and other inflammatory cells to damage the esophagus. Recent studies have identified small molecule inhibitors of HIF-2α that demonstrate exquisite isoform selectivity, and clinical trials for treatment of HIF-2α-driven kidney cancers are ongoing. It is conceivable that a HIF-2α-directed therapy might be a novel approach to prevention and treatment of reflux esophagitis.
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Affiliation(s)
- Rhonda F Souza
- Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, TX, USA.
| | - Liela Bayeh
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Stuart J Spechler
- Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, TX, USA
| | - Uttam K Tambar
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Richard K Bruick
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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27
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Huo X, Agoston AT, Dunbar KB, Cipher DJ, Zhang X, Yu C, Cheng E, Zhang Q, Pham TH, Tambar UK, Bruick RK, Wang DH, Odze RD, Spechler SJ, Souza RF. Hypoxia-inducible factor-2α plays a role in mediating oesophagitis in GORD. Gut 2017; 66:1542-1554. [PMID: 27694141 PMCID: PMC5464991 DOI: 10.1136/gutjnl-2016-312595] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/24/2016] [Accepted: 09/08/2016] [Indexed: 12/14/2022]
Abstract
OBJECTIVE In an earlier study wherein we induced acute reflux by interrupting proton pump inhibitor (PPI) therapy in patients with reflux oesophagitis (RO) healed by PPIs, we refuted the traditional concept that RO develops as an acid burn. The present study explored our alternative hypothesis that RO results from reflux-stimulated production of pro-inflammatory molecules mediated by hypoxia-inducible factors (HIFs). DESIGN Using oesophageal biopsies taken from patients in our earlier study at baseline and at 1 and 2 weeks off PPIs, we immunostained for HIF-1α, HIF-2α and phospho-p65, and measured pro-inflammatory molecule mRNAs. We exposed human oesophageal squamous cell lines to acidic bile salts, and evaluated effects on HIF activation, p65 function, pro-inflammatory molecule production and immune cell migration. RESULTS In patient biopsies, increased immunostaining for HIF-2α and phospho-p65, and increased pro-inflammatory molecule mRNA levels were seen when RO redeveloped 1 or 2 weeks after stopping PPIs. In oesophageal cells, exposure to acidic bile salts increased intracellular reactive oxygen species, which decreased prolyl hydroxylase function and stabilised HIF-2α, causing a p65-dependent increase in pro-inflammatory molecules; conditioned media from these cells increased T cell migration rates. HIF-2α inhibition by small hairpin RNA or selective small molecule antagonist blocked the increases in pro-inflammatory molecule expression and T cell migration induced by acidic bile salts. CONCLUSIONS In patients developing RO, increases in oesophageal HIF-2α correlate with increased pro-inflammatory molecule expression. In oesophageal epithelial cells, acidic bile salts stabilise HIF-2α, which mediates expression of pro-inflammatory molecules. HIF-2α appears to have a role in RO pathogenesis. TRIAL REGISTRATION NUMBER NCT01733810; Results.
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Affiliation(s)
- Xiaofang Huo
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Agoston T. Agoston
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Kerry B. Dunbar
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Daisha J. Cipher
- College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, TX
| | - Xi Zhang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Chunhua Yu
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Edaire Cheng
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Pediatrics, Children's Medical Center and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Qiuyang Zhang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Thai H. Pham
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Surgery, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Uttam K. Tambar
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Richard K. Bruick
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - David H. Wang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX
| | - Robert D. Odze
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Stuart J. Spechler
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX,Correspondence to: Rhonda F. Souza, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0301, FAX 214-857-0328, ; Stuart J. Spechler, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0403, FAX 214-857-1571,
| | - Rhonda F. Souza
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX,Correspondence to: Rhonda F. Souza, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0301, FAX 214-857-0328, ; Stuart J. Spechler, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0403, FAX 214-857-1571,
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28
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Abstract
The [1,2]- and [2,3]-rearrangements of iodonium ylides are synthetically useful reactions for the generation of functionalized α-iodoesters. Allylic iodides are coupled with α-diazoesters in the presence of a copper catalyst and a ligand to generate iodonium ylides, which undergo metal-mediated rearrangements. By fine-tuning the structure of the ligand, we have reversed the regioselectivity of copper-catalyzed reactions of iodonium ylides from [2,3]- to [1,2]-rearrangements with the use of alternate bipyridine ligands. The preference for [1,2]-rearrangements was further improved by using bulky aryl α-diazoester substrates. Several α-iodoesters with a diverse range of functional groups were generated in good yields (up to 88% yield) and high regioselectivities (up to >95:5 regioisomeric ratio). A deuterium-labeled substrate was utilized to gain insight into the mechanism of the reaction.
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Affiliation(s)
- Bin Xu
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Jackson Gartman
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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Xu B, Tambar UK. Copper-Catalyzed Enantio-, Diastereo-, and Regioselective [2,3]-Rearrangements of Iodonium Ylides. Angew Chem Int Ed Engl 2017; 56:9868-9871. [PMID: 28600841 DOI: 10.1002/anie.201705317] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [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: 05/23/2017] [Indexed: 11/06/2022]
Abstract
The first highly enantioselective, diastereoselective, and regioselective [2,3]-rearrangement of iodonium ylides has been developed as a general solution to catalytic onium ylide rearrangements. In the presence of a chiral copper catalyst, substituted allylic iodides couple with α-diazoesters to generate metal-coordinated iodonium ylides, which undergo [2,3]-rearrangements with high selectivities (up to >95:5 r.r., up to >95:5 d.r., and up to 97 % ee). The enantioenriched iodoester products can be converted stereospecifically into a variety of onium ylide rearrangement products, as well as compounds that are not accessible by classical onium ylide rearrangements.
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Affiliation(s)
- Bin Xu
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
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30
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Affiliation(s)
- Bin Xu
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Uttam K. Tambar
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
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31
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Abstract
The stereoselective oxidation of hydrocarbons is one of the most notable advances in synthetic chemistry over the past fifty years. Inspired by nature, enantioselective dihydroxylations, epoxidations and other oxidations of unsaturated hydrocarbons have been developed. More recently, the catalytic enantioselective allylic carbon-hydrogen oxidation of alkenes has streamlined the production of pharmaceuticals, natural products, fine chemicals and other functional materials. Allylic functionalization provides a direct path to chiral building blocks with a newly formed stereocentre from petrochemical feedstocks while preserving the olefin functionality as a handle for further chemical elaboration. Various metal-based catalysts have been discovered for the enantioselective allylic carbon-hydrogen oxidation of simple alkenes with cyclic or terminal double bonds. However, a general and selective allylic oxidation using the more common internal alkenes remains elusive. Here we report the enantioselective, regioselective and E/Z-selective allylic oxidation of unactivated internal alkenes via a catalytic hetero-ene reaction with a chalcogen-based oxidant. Our method enables non-symmetric internal alkenes to be selectively converted into allylic functionalized products with high stereoselectivity and regioselectivity. Stereospecific transformations of the resulting multifunctional chiral building blocks highlight the potential for rapidly converting internal alkenes into a broad range of enantioenriched structures that can be used in the synthesis of complex target molecules.
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Affiliation(s)
- Liela Bayeh
- Department of Biochemistry, The University of Texas Southwestern
Medical Center, 5323 Harry, Hines Boulevard, Dallas, Texas 75390-9038, United
States
| | - Phong Q. Le
- Department of Biochemistry, The University of Texas Southwestern
Medical Center, 5323 Harry, Hines Boulevard, Dallas, Texas 75390-9038, United
States
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern
Medical Center, 5323 Harry, Hines Boulevard, Dallas, Texas 75390-9038, United
States
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32
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33
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34
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Affiliation(s)
- Christopher E. Sleet
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
| | - Uttam K. Tambar
- Department of Biochemistry The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas TX 75390-9038 USA
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35
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Abstract
Heteroatom-containing organic molecules are of particular interest to medicinal chemists and materials scientists. A strategy to reach these architectures via direct difunctionalization of abundant 1,3-dienes is especially attractive. Herein, we describe the development of a regio- and diastereoselective 1,4-aminothiolation of 1,3-dienes with a sulfur diimide reagent, a copper catalyst, and alkyl Grignard reagents. This unique protocol provides remote nitrogen and sulfur functionalities with high levels of stereocontrol. The reaction proceeds via a tandem hetero-Diels-Alder cycloaddition of N,N'-bis(benzenesulfonyl)sulfur diimide with 1,3-diene followed by copper-catalyzed Grignard substitution. Mechanistic studies support a copper catalyzed formation of an unprecedented [10-S-4] sulfurane that reductively eliminates to afford a 3,6-dihydrothiazine, which is selectively converted to 1,4-aminothiols.
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Affiliation(s)
- Christopher E Sleet
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9038, USA
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36
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Abstract
Despite the importance of allylic ylide rearrangements for the synthesis of complex molecules, the catalyst control of [2,3]- and [1,2]-rearrangements remains an unsolved problem. We developed the first regiodivergent [2,3]- and [1,2]-rearrangements of iodonium ylides that are controlled by copper catalysts bearing different ligands. In the presence of a 2,2'-dipyridyl ligand, diazoesters and allylic iodides react via a [2,3]-rearrangement pathway. Alternatively, a phosphine ligand favors the formation of the [1,2]-rearrangement product. A series of α-iodoesters containing a broad range of functional groups were obtained in high yields, regioselectivities, and diastereoselectivities. Deuterium-labeling studies suggest distinct mechanisms for the regioselective rearrangements.
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Affiliation(s)
- Bin Xu
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas , 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas , 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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37
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Scheuermann TH, Stroud D, Sleet CE, Bayeh L, Shokri C, Wang H, Caldwell CG, Longgood J, MacMillan JB, Bruick RK, Gardner KH, Tambar UK. Isoform-Selective and Stereoselective Inhibition of Hypoxia Inducible Factor-2. J Med Chem 2015. [DOI: 10.1021/acs.jmedchem.5b00529] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Thomas H. Scheuermann
- Department
of Biophysics, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Daniel Stroud
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Christopher E. Sleet
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Liela Bayeh
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Cameron Shokri
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Hanzhi Wang
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Charles G. Caldwell
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Jamie Longgood
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - John B. MacMillan
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Richard K. Bruick
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Kevin H. Gardner
- Department
of Biophysics, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
- Structural
Biology Initiative, CUNY Advanced Science Research Center, New York, New York 10031, United States
- Department
of Chemistry and Biochemistry, City College of New York, New York, New York 10031, United States
| | - Uttam K. Tambar
- Department
of Biochemistry, University of Texas Southwestern Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United States
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38
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Tso SC, Gui WJ, Wu CY, Chuang JL, Qi X, Skvora KJ, Dork K, Wallace AL, Morlock LK, Lee BH, Hutson SM, Strom SC, Williams NS, Tambar UK, Wynn RM, Chuang DT. Benzothiophene carboxylate derivatives as novel allosteric inhibitors of branched-chain α-ketoacid dehydrogenase kinase. J Biol Chem 2015; 289:20583-93. [PMID: 24895126 DOI: 10.1074/jbc.m114.569251] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The mitochondrial branched-chain α-ketoacid dehydrogenase complex (BCKDC) is negatively regulated by reversible phosphorylation.BCKDC kinase (BDK) inhibitors that augment BCKDC flux have been shown to reduce branched-chain amino acid (BCAA) concentrations in vivo. In the present study, we employed high-throughput screens to identify compound 3,6- dichlorobenzo[b]thiophene-2-carboxylic acid (BT2) as a novel BDK inhibitor (IC(50) = 3.19 μM). BT2 binds to the same site in BDK as other known allosteric BDK inhibitors, including (S)-α-cholorophenylproprionate ((S)-CPP). BT2 binding to BDK triggers helix movements in the N-terminal domain, resulting in the dissociation of BDK from the BCKDC accompanied by accelerated degradation of the released kinase in vivo. BT2 shows excellent pharmacokinetics (terminal T(1⁄2) = 730 min) and metabolic stability (no degradation in 240 min), which are significantly better than those of (S)-CPP. BT2, its analog 3-chloro-6-fluorobenzo[ b]thiophene-2-carboxylic acid (BT2F), and a prodrug of BT2 (i.e. N-(4-acetamido-1,2,5-oxadiazol-3-yl)-3,6-dichlorobenzo[ b]thiophene-2-carboxamide (BT3)) significantly increase residual BCKDC activity in cultured cells and primary hepatocytes from patients and a mouse model of maple syrup urine disease. Administration of BT2 at 20 mg/kg/day to wild-type mice for 1 week leads to nearly complete dephosphorylation and maximal activation of BCKDC in heart, muscle, kidneys, and liver with reduction in plasma BCAA concentrations. The availability of benzothiophene carboxylate derivatives as stable BDK inhibitors may prove useful for the treatment of metabolic disease caused by elevated BCAA concentrations.
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39
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Abstract
The palladium-catalyzed coupling of olefins and organohalides is a versatile approach for synthesizing complex molecules from simple starting materials. We have developed a palladium-catalyzed coupling of α-bromocarbonyl compounds with allylic alcohols for the generation of acyclic aryl-substituted dicarbonyl compounds. The reaction proceeds via a tandem olefin insertion of an α-acyl radical followed by a 1,2-aryl migration. In addition to providing preliminary evidence for a free radical mediated mechanism, we demonstrate unprecedented levels of 1,3-stereoinduction for the 1,2-migration step.
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Affiliation(s)
- Yang Yu
- The University of Texas Southwestern Medical Center at Dallas, Department of Biochemistry, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA
| | - Uttam K Tambar
- The University of Texas Southwestern Medical Center at Dallas, Department of Biochemistry, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA
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40
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Abstract
The 1,4-functionalization of dienes is a synthetically useful strategy for incorporating molecular complexity into a class of simple substrates. We report the aminoarylation of acyclic and cyclic 1,3-dienes via the sequential [4+2] cycloaddition with a sulfurdiimide reagent and copper-catalyzed allylic substitution with Grignard reagents. The regioselective and diastereoselective aminoarylation of unsymmetrical dienes is also presented, which highlights the utility of this method for generating products with multiple functional groups and stereocenters.
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Affiliation(s)
- Hongli Bao
- The University of Texas Southwestern Medical Center at Dallas, Department of Biochemistry, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA. ; Tel: +1-214-648-0580
| | - Liela Bayeh
- The University of Texas Southwestern Medical Center at Dallas, Department of Biochemistry, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA. ; Tel: +1-214-648-0580
| | - Uttam K Tambar
- The University of Texas Southwestern Medical Center at Dallas, Department of Biochemistry, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, USA. ; Tel: +1-214-648-0580
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41
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42
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Bao H, Bayeh L, Tambar UK. Allylic functionalization of unactivated olefins with Grignard reagents. Angew Chem Int Ed Engl 2014; 53:1664-8. [PMID: 24458538 DOI: 10.1002/anie.201309134] [Citation(s) in RCA: 18] [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: 10/18/2013] [Revised: 11/19/2013] [Indexed: 11/09/2022]
Abstract
New advances in the functionalization of unactivated olefins with carbon nucleophiles have provided more efficient and practical approaches to convert inexpensive starting materials into valuable products. Recent examples have been reported with stabilized carbon nucleophiles, tethered carbon nucleophiles, diazoesters, and trifluoromethane donors. A general method for functionalizing olefins with aromatic, aliphatic, and vinyl Grignard reagents was developed. In a one-pot process, olefins are oxidized by a commercially available reagent to allylic electrophiles, which undergo selective copper-catalyzed allylic alkylation with Grignard reagents. Products are formed in high yield and with high regioselectivity. This was utilized to synthesize a series of skipped dienes, a class of compounds that are prevalent in natural products and are difficult to synthesize by known allylic alkylation methods.
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Affiliation(s)
- Hongli Bao
- Department of Biochemistry, The University of Texas, Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390-9038 (USA) http://www4.utsouthwestern.edu/tambarlab/
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43
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Tso SC, Qi X, Gui WJ, Wu CY, Chuang JL, Wernstedt-Asterholm I, Morlock LK, Owens KR, Scherer PE, Williams NS, Tambar UK, Wynn RM, Chuang DT. Structure-guided development of specific pyruvate dehydrogenase kinase inhibitors targeting the ATP-binding pocket. J Biol Chem 2013; 289:4432-43. [PMID: 24356970 DOI: 10.1074/jbc.m113.533885] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pyruvate dehydrogenase kinase isoforms (PDKs 1-4) negatively regulate activity of the mitochondrial pyruvate dehydrogenase complex by reversible phosphorylation. PDK isoforms are up-regulated in obesity, diabetes, heart failure, and cancer and are potential therapeutic targets for these important human diseases. Here, we employed a structure-guided design to convert a known Hsp90 inhibitor to a series of highly specific PDK inhibitors, based on structural conservation in the ATP-binding pocket. The key step involved the substitution of a carbonyl group in the parent compound with a sulfonyl in the PDK inhibitors. The final compound of this series, 2-[(2,4-dihydroxyphenyl)sulfonyl]isoindoline-4,6-diol, designated PS10, inhibits all four PDK isoforms with IC50 = 0.8 μM for PDK2. The administration of PS10 (70 mg/kg) to diet-induced obese mice significantly augments pyruvate dehydrogenase complex activity with reduced phosphorylation in different tissues. Prolonged PS10 treatments result in improved glucose tolerance and notably lessened hepatic steatosis in the mouse model. The results support the pharmacological approach of targeting PDK to control both glucose and fat levels in obesity and type 2 diabetes.
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44
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Abstract
The presence of nitrogen atoms in most chiral pharmaceutical drugs has motivated the development of numerous strategies for the synthesis of enantioenriched amines. Current methods are based on the multi-step transformation of pre-functionalized allylic electrophiles into chiral allylic amines. The enantioselective allylic amination of unactivated olefins represents a more direct and attractive strategy. We report the enantioselective synthesis of ent-sitagliptin via an allylic amination of an unactivated terminal olefin.
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Affiliation(s)
- Hongli Bao
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Liela Bayeh
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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45
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Maity P, Pemberton RP, Tantillo DJ, Tambar UK. Brønsted Acid Catalyzed Enantioselective Indole Aza-Claisen Rearrangement Mediated by an Arene CH–O Interaction. J Am Chem Soc 2013; 135:16380-3. [DOI: 10.1021/ja4095473] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [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)
- Pradip Maity
- Department
of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Ryan P. Pemberton
- Department
of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Dean J. Tantillo
- Department
of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Uttam K. Tambar
- Department
of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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46
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Soheili A, Tambar UK. Synthesis of (±)-Amathaspiramide F and Discovery of an Unusual Stereocontrolling Element for the [2,3]-Stevens Rearrangement. Org Lett 2013; 15:5138-41. [DOI: 10.1021/ol4025937] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [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)
- Arash Soheili
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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47
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Nash A, Soheili A, Tambar UK. Stereoselective Synthesis of Functionalized Cyclic Amino Acid Derivatives via a [2,3]-Stevens Rearrangement and Ring-Closing Metathesis. Org Lett 2013; 15:4770-3. [DOI: 10.1021/ol402129h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Aaron Nash
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Arash Soheili
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K. Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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48
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Scheuermann TH, Li Q, Ma HW, Key J, Zhang L, Chen R, Garcia JA, Naidoo J, Longgood J, Frantz DE, Tambar UK, Gardner KH, Bruick RK. Allosteric inhibition of hypoxia inducible factor-2 with small molecules. Nat Chem Biol 2013; 9:271-6. [PMID: 23434853 PMCID: PMC3604136 DOI: 10.1038/nchembio.1185] [Citation(s) in RCA: 221] [Impact Index Per Article: 20.1] [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: 08/13/2012] [Accepted: 01/18/2013] [Indexed: 02/07/2023]
Abstract
Hypoxia inducible factors (HIFs) are heterodimeric transcription factors induced in many cancers where they frequently promote the expression of protumorigenic pathways. Though transcription factors are typically considered 'undruggable', the PAS-B domain of the HIF-2α subunit contains a large cavity within its hydrophobic core that offers a unique foothold for small-molecule regulation. Here we identify artificial ligands that bind within this pocket and characterize the resulting structural and functional changes caused by binding. Notably, these ligands antagonize HIF-2 heterodimerization and DNA-binding activity in vitro and in cultured cells, reducing HIF-2 target gene expression. Despite the high sequence identity between HIF-2α and HIF-1α, these ligands are highly selective and do not affect HIF-1 function. These chemical tools establish the molecular basis for selective regulation of HIF-2, providing potential therapeutic opportunities to intervene in HIF-2-driven tumors, such as renal cell carcinomas.
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Affiliation(s)
- Thomas H Scheuermann
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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49
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Rogers JL, Bayeh L, Scheuermann TH, Longgood J, Key J, Naidoo J, Melito L, Shokri C, Frantz DE, Bruick RK, Gardner KH, MacMillan JB, Tambar UK. Development of inhibitors of the PAS-B domain of the HIF-2α transcription factor. J Med Chem 2013; 56:1739-47. [PMID: 23363003 DOI: 10.1021/jm301847z] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Hypoxia inducible factors (HIFs) are heterodimeric transcription factors induced in a variety of pathophysiological settings, including cancer. We describe the first detailed structure-activity relationship study of small molecules designed to inhibit HIF-2α-ARNT heterodimerization by binding an internal cavity of the HIF-2α PAS-B domain. Through a series of biophysical characterizations of inhibitor-protein interactions (NMR and X-ray crystallography), we have established the structural requirements for artificial inhibitors of the HIF-2α-ARNT PAS-B interaction. These results may serve as a foundation for discovering therapeutic agents that function by a novel mode of action.
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Affiliation(s)
- Jamie L Rogers
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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50
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Bao H, Tambar UK. Catalytic enantioselective allylic amination of unactivated terminal olefins via an ene reaction/[2,3]-rearrangement. J Am Chem Soc 2012; 134:18495-8. [PMID: 23106555 DOI: 10.1021/ja307851b] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The enantioselective allylic amination of unactivated terminal olefins represents a direct and attractive strategy for the synthesis of enantioenriched amines. We have developed the first use of a nitrogen-containing reagent and a chiral palladium catalyst to convert unfunctionalized olefins into enantioenriched allylic amines via an ene reaction/[2,3]-rearrangement.
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Affiliation(s)
- Hongli Bao
- Department of Biochemistry, Division of Chemistry, The University of Texas Southwestern Medical Center at Dallas, 75390-9038, United States
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