1
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Xiong TZ, Yisimayili N, Lu CD. Stereoselective Electrophilic Chlorination of β,β-Disubstituted Enesulfinamides with Chloramine-T: Asymmetric Synthesis of Acyclic α,α-Disubstituted α-Chlorinated Carbonyl Surrogates. Org Lett 2024; 26:1851-1856. [PMID: 38386702 DOI: 10.1021/acs.orglett.4c00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Enamine and iminium ion-mediated asymmetric organocatalysis was not successful in achieving highly stereoselective α-chlorination of acyclic α,α-disubstituted carbonyls. To address this limitation, an alternative method was developed, which involved the use of geometry-defined persubstituted enesulfinamides to intercept the electrophilic chlorinating reagent. This approach enables the asymmetric construction of challenging acyclic α,α-disubstituted α-chlorinated ketimines with a high degree of stereoselectivity. The use of chloramine-T, a cost-effective and stable chlorine source rarely utilized in asymmetric electrophilic chlorination, plays a crucial role in achieving superior stereocontrol.
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Affiliation(s)
- Teng-Zhao Xiong
- School of Chemical Science and Technology, Yunnan University, Kunming, Yunnan 650091, China
| | | | - Chong-Dao Lu
- School of Chemical Science and Technology, Yunnan University, Kunming, Yunnan 650091, China
- School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
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2
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Li Z, Wang B, Zhang C, Lo WY, Yang L, Sun J. Catalytic Enantioselective Nucleophilic α-Chlorination of Ketones with NaCl. J Am Chem Soc 2024; 146:2779-2788. [PMID: 38238317 DOI: 10.1021/jacs.3c12826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Catalytic enantioselective α-chlorination of ketones is a highly desirable process. Different from the conventional approaches that employ corrosive electrophilic chlorination reagents, the process disclosed here employs nucleophilic chloride, aqueous NaCl solution, and even seawater, as green inexpensive chlorine sources. This mechanistically distinct and electronically opposite approach provides facile access to diverse highly enantioenriched acyclic α-chloro ketones that are less straightforward by conventional approaches. With a chiral thiourea catalyst, a range of racemic α-keto sulfonium salts underwent enantioconvergent carbon-chlorine bond formation with high efficiency and excellent enantioselectivity under mild conditions. The sulfonium motif plays a crucial triple role by permitting smooth dynamic kinetic resolution to take place via a chiral anion binding mechanism in a well-designed phase-transfer system. This protocol represents a new general platform for the asymmetric nucleophilic α-functionalization of carbonyl compounds.
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Affiliation(s)
- Zhiyang Li
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
- Shenzhen Research Institute, HKUST, No. 9 Yuexing First Rd, Shenzhen 518057, China
| | - Baocheng Wang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Chaoshen Zhang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Wai Yam Lo
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Liangliang Yang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Jianwei Sun
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
- Shenzhen Research Institute, HKUST, No. 9 Yuexing First Rd, Shenzhen 518057, China
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3
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Chen X, Patel K, Marek I. Stereospecific nucleophilic substitution at quaternary carbon stereocenters of cyclopropyl carbinols. Chem 2023. [DOI: 10.1016/j.chempr.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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4
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Chen X, Marek I. Stereoinvertive Nucleophilic Substitution at Quaternary Carbon Stereocenters of Cyclopropyl Ketones and Ethers. Angew Chem Int Ed Engl 2022; 61:e202203673. [PMID: 35471589 PMCID: PMC9324837 DOI: 10.1002/anie.202203673] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Indexed: 11/09/2022]
Abstract
A highly regio‐ and diastereoselective nucleophilic substitution at the quaternary carbon stereocenter of cyclopropyl ketones and cyclopropyl carbinol derivatives using TMSBr, DMPSCl and TMSN3 as nucleophiles has been developed. A variety of acyclic tertiary alkyl bromides, chlorides and azides were therefore prepared with excellent diastereopurity. The substitution occurs at the most substituted quaternary carbon center in a stereoinvertive manner, which may be attributed to the existence of a bicyclobutonium species.
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Affiliation(s)
- Xu Chen
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa, 3200009, Israel
| | - Ilan Marek
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa, 3200009, Israel
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5
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Chen X, Marek I. Stereoinvertive Nucleophilic Substitution at Quaternary Carbon Stereocenters of Cyclopropyl Ketones and Ethers. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202203673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xu Chen
- Schulich Faculty of Chemistry Technion-Israel Institute of Technology Technion City Haifa 3200009 Israel
| | - Ilan Marek
- Schulich Faculty of Chemistry Technion-Israel Institute of Technology Technion City Haifa 3200009 Israel
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6
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Nishimura K, Wang Y, Ogura Y, Kumagai J, Ishihara K. A π–Cu(II)−π Complex as an Extremely Active Catalyst for Enantioselective α-Halogenation of N-Acyl-3,5-dimethylpyrazoles. ACS Catal 2022. [DOI: 10.1021/acscatal.1c05500] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Kazuki Nishimura
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Yanzhao Wang
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Yoshihiro Ogura
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Jun Kumagai
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Kazuaki Ishihara
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
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7
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Zebrowski P, Eder I, Eitzinger A, Mallojjala SC, Waser M. Enantioselective Catalytic Synthesis of α-Halogenated α-Aryl-β 2,2-amino Acid Derivatives. ACS ORGANIC & INORGANIC AU 2021; 2:34-43. [PMID: 35141714 PMCID: PMC8815071 DOI: 10.1021/acsorginorgau.1c00025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 01/22/2023]
Abstract
The enantioselective synthesis of a broad variety of novel differently functionalized α-halogenated α-aryl-β2,2-amino acid derivatives by means of an ammonium-salt-catalyzed asymmetric α-halogenation of isoxazolidin-5-ones was accomplished. Key to success to obtain high levels of enantioselectivities was the use of Maruoka's spirocyclic binaphthyl-based ammonium salts, and detailed accompanying mechanistic studies using density functional theory methods revealed the key features for the catalyst-substrate interactions.
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Affiliation(s)
- Paul Zebrowski
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Isabella Eder
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Andreas Eitzinger
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Sharath Chandra Mallojjala
- Department
of Chemistry, State University of New York
at Binghamton, Binghamton, New York 13902, United States,
| | - Mario Waser
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria,Phone: +4373224685411.
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8
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García‐Urricelqui A, Cózar A, Campano TE, Mielgo A, Palomo C. syn
‐Selective Michael Reaction of α‐Branched Aryl Acetaldehydes with Nitroolefins Promoted by Squaric Amino Acid Derived Bifunctional Brønsted Bases. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Ane García‐Urricelqui
- Departamento de Química Orgánica I Universidad del País Vasco UPV/EHU Manuel Lardizábal 3 20018 San Sebastián Spain
| | - Abel Cózar
- Departamento de Química Orgánica I Universidad del País Vasco UPV/EHU Manuel Lardizábal 3 20018 San Sebastián Spain
- IKERBASQUE Basque Foundation for Science 48009 Blbao Spain
| | - Teresa E. Campano
- Departamento de Química Orgánica I Universidad del País Vasco UPV/EHU Manuel Lardizábal 3 20018 San Sebastián Spain
| | - Antonia Mielgo
- Departamento de Química Orgánica I Universidad del País Vasco UPV/EHU Manuel Lardizábal 3 20018 San Sebastián Spain
| | - Claudio Palomo
- Departamento de Química Orgánica I Universidad del País Vasco UPV/EHU Manuel Lardizábal 3 20018 San Sebastián Spain
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9
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Strassfeld DA, Algera RF, Wickens ZK, Jacobsen EN. A Case Study in Catalyst Generality: Simultaneous, Highly-Enantioselective Brønsted- and Lewis-Acid Mechanisms in Hydrogen-Bond-Donor Catalyzed Oxetane Openings. J Am Chem Soc 2021; 143:9585-9594. [PMID: 34152759 PMCID: PMC8564877 DOI: 10.1021/jacs.1c03992] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Generality in asymmetric catalysis can be manifested in dramatic and valuable ways, such as high enantioselectivity across a wide assortment of substrates in a given reaction (broad substrate scope) or as applicability of a given chiral framework across a variety of mechanistically distinct reactions (privileged catalysts). Reactions and catalysts that display such generality hold special utility, because they can be applied broadly and sometimes even predictably in new applications. Despite the great value of such systems, the factors that underlie generality are not well understood. Here, we report a detailed investigation of an asymmetric hydrogen-bond-donor catalyzed oxetane opening with TMSBr that is shown to possess unexpected mechanistic generality. Careful analysis of the role of adventitious protic impurities revealed the participation of competing pathways involving addition of either TMSBr or HBr in the enantiodetermining, ring-opening event. The optimal catalyst induces high enantioselectivity in both pathways, thereby achieving precise stereocontrol in fundamentally different mechanisms under the same conditions and with the same chiral framework. The basis for that generality is analyzed using a combination of experimental and computational methods, which indicate that proximally localized catalyst components cooperatively stabilize and precisely orient dipolar enantiodetermining transition states in both pathways. Generality across different mechanisms is rarely considered in catalyst discovery efforts, but we suggest that it may play a role in the identification of so-called privileged catalysts.
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Affiliation(s)
- Daniel A Strassfeld
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Russell F Algera
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Zachary K Wickens
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Eric N Jacobsen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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10
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Zhang X, Tan CH. Stereospecific and stereoconvergent nucleophilic substitution reactions at tertiary carbon centers. Chem 2021. [DOI: 10.1016/j.chempr.2020.11.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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11
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García-Urricelqui A, de Cózar A, Mielgo A, Palomo C. Probing α-Amino Aldehydes as Weakly Acidic Pronucleophiles: Direct Access to Quaternary α-Amino Aldehydes by an Enantioselective Michael Addition Catalyzed by Brønsted Bases. Chemistry 2021; 27:2483-2492. [PMID: 33034390 DOI: 10.1002/chem.202004468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Indexed: 12/20/2022]
Abstract
The high tendency of α-amino aldehydes to undergo 1,2-additions and their relatively low stability under basic conditions have largely prevented their use as pronucleophiles in the realm of asymmetric catalysis, particularly for the production of quaternary α-amino aldehydes. Herein, it is demonstrated that the chemistry of α-amino aldehydes may be expanded beyond these limits by documenting the first direct α-alkylation of α-branched α-amino aldehydes with nitroolefins. The reaction produces densely functionalized products bearing up to two, quaternary and tertiary, vicinal stereocenters with high diastereo- and enantioselectivity. DFT modeling leads to the proposal that intramolecular hydrogen bonding between the NH group and the carbonyl oxygen atom in the starting α-amino aldehyde is key for reaction stereocontrol.
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Affiliation(s)
- Ane García-Urricelqui
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizábal 3, 20018, San Sebastián, Spain
| | - Abel de Cózar
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizábal 3, 20018, San Sebastián, Spain.,IKERBASQUE, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Antonia Mielgo
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizábal 3, 20018, San Sebastián, Spain
| | - Claudio Palomo
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizábal 3, 20018, San Sebastián, Spain
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12
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Stockhammer L, Schörgenhumer J, Mairhofer C, Waser M. Asymmetric α-Chlorination of β-Keto Esters Using Hypervalent Iodine-Based Cl-Transfer Reagents in Combination with Cinchona Alkaloid Catalysts. European J Org Chem 2021; 2021:82-86. [PMID: 33519300 PMCID: PMC7821243 DOI: 10.1002/ejoc.202001217] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Indexed: 01/29/2023]
Abstract
We herein report an unprecedented strategy for the asymmetric α-chlorination of β-keto esters with hypervalent iodine-based Cl-transfer reagents using simple Cinchona alkaloid catalysts. Our investigations support an α-chlorination mechanism where the Cinchona species serves as a nucleophilic catalyst by reacting with the chlorinating agent to generate a chiral electrophilic Cl-transfer reagent in situ. Using at least 20 mol-% of the alkaloid catalyst allows for good yields and enantioselectivities for a variety of different β-keto esters under operationally simple conditions.
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Affiliation(s)
- Lotte Stockhammer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Johannes Schörgenhumer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Christopher Mairhofer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
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13
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Asymmetric Synthesis of Tertiary α -Hydroxyketones by Enantioselective Decarboxylative Chlorination and Subsequent Nucleophilic Substitution. Molecules 2020; 25:molecules25173902. [PMID: 32867091 PMCID: PMC7503659 DOI: 10.3390/molecules25173902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 11/17/2022] Open
Abstract
Chiral tertiary α-hydroxyketones were synthesized with high enantiopurity by asymmetric decarboxylative chlorination and subsequent nucleophilic substitution. We recently reported the asymmetric decarboxylative chlorination of β-ketocarboxylic acids in the presence of a chiral primary amine catalyst to obtain α-chloroketones with high enantiopurity. Here, we found that nucleophilic substitution of the resulting α-chloroketones with tetrabutylammonium hydroxide yielded the corresponding α-hydroxyketones without loss of enantiopurity. The reaction proceeded smoothly even at a tertiary carbon. The proposed method would be useful for the preparation of chiral tertiary alcohols.
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14
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Liu Y, Leng H, Li Q, Li J. Catalytic Strategies for the Asymmetric Construction of Cyclic Frameworks with a Halogenated Tetrasubstituted Stereocenter. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000540] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yue Liu
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province Sichuan Industrial Institute of Antibiotics Chengdu University Chengdu 610052 PR China
| | - Hai‐Jun Leng
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province Sichuan Industrial Institute of Antibiotics Chengdu University Chengdu 610052 PR China
| | - Qing‐Zhu Li
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province Sichuan Industrial Institute of Antibiotics Chengdu University Chengdu 610052 PR China
| | - Jun‐Long Li
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province Sichuan Industrial Institute of Antibiotics Chengdu University Chengdu 610052 PR China
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15
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Andres R, Wang Q, Zhu J. Asymmetric Total Synthesis of (−)-Arborisidine and (−)-19-epi-Arborisidine Enabled by a Catalytic Enantioselective Pictet–Spengler Reaction. J Am Chem Soc 2020; 142:14276-14285. [DOI: 10.1021/jacs.0c05804] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Rémi Andres
- Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN BCH5304, CH-1015 Lausanne, Switzerland
| | - Qian Wang
- Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN BCH5304, CH-1015 Lausanne, Switzerland
| | - Jieping Zhu
- Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN BCH5304, CH-1015 Lausanne, Switzerland
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16
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Zhan X, Du X. Regio- and Enantioselective Epoxy Ring Opening of
2,3-Epoxy-3-phenyl Alcohols/Carboxylic Acids and Their Derivatives. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2020. [DOI: 10.1134/s107042802004017x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Ren J, Ban X, Zhang X, Tan SM, Lee R, Tan C. Kinetic and Dynamic Kinetic Resolution of Racemic Tertiary Bromides by Pentanidium‐Catalyzed Phase‐Transfer Azidation. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000138] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Jingyun Ren
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University Xi'an Shaanxi 710127 P. R. China
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
| | - Xu Ban
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
| | - Xin Zhang
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
| | - Siu Min Tan
- Science and Mathematics Cluster Singapore University of Technology and Design 8 Somapah Road Singapore 487372 Singapore
| | - Richmond Lee
- Science and Mathematics Cluster Singapore University of Technology and Design 8 Somapah Road Singapore 487372 Singapore
| | - Choon‐Hong Tan
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
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18
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Ren J, Ban X, Zhang X, Tan SM, Lee R, Tan C. Kinetic and Dynamic Kinetic Resolution of Racemic Tertiary Bromides by Pentanidium‐Catalyzed Phase‐Transfer Azidation. Angew Chem Int Ed Engl 2020; 59:9055-9058. [DOI: 10.1002/anie.202000138] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Indexed: 12/29/2022]
Affiliation(s)
- Jingyun Ren
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education College of Chemistry and Materials Science Northwest University Xi'an Shaanxi 710127 P. R. China
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
| | - Xu Ban
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
| | - Xin Zhang
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
| | - Siu Min Tan
- Science and Mathematics Cluster Singapore University of Technology and Design 8 Somapah Road Singapore 487372 Singapore
| | - Richmond Lee
- Science and Mathematics Cluster Singapore University of Technology and Design 8 Somapah Road Singapore 487372 Singapore
| | - Choon‐Hong Tan
- Division of Chemistry and Biological Chemistry Nanyang Technological University 21 Nanyang Link 637371 Singapore Singapore
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19
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Attard JW, Osawa K, Guan Y, Hatt J, Kondo SI, Mattson A. Silanediol Anion Binding and Enantioselective Catalysis. SYNTHESIS-STUTTGART 2019; 51:2107-2115. [PMID: 31178610 PMCID: PMC6548508 DOI: 10.1055/s-0037-1612217] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Silanediols possess unique and complementary catalytic activity in reactions that are likely to proceed through anion binding. This article directly compares silanediols, thioureas, and squaramides in three separate anion-binding processes. The catalytic abilities of select members of each family are directly correlated to association constant.
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Affiliation(s)
- Jonathan W. Attard
- Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, Worcester, MA 01609, USA
| | - Kohei Osawa
- Yamagata University, Department of Science, Faculty of Science, Yamagata, Yamagata 990-8560, Japan
| | - Yong Guan
- Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, Worcester, MA 01609, USA
| | - Jessica Hatt
- Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, Worcester, MA 01609, USA
| | - Shin-ichi Kondo
- Yamagata University, Department of Science, Faculty of Science, Yamagata, Yamagata 990-8560, Japan
| | - Anita Mattson
- Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, Worcester, MA 01609, USA
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20
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Affiliation(s)
- Shinji Yamada
- Department of Chemistry, Faculty of Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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21
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Gokada MR, Hunter R, Andrijevic A, Petersen WF, Samanta S, Venter G, Rees-Jones S. Quaternized α,α'-Amino Acids via Curtius Rearrangement of Substituted Malonate-Imidazolidinones. J Org Chem 2017; 82:10650-10658. [PMID: 28903002 DOI: 10.1021/acs.joc.7b01684] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An efficient synthesis protocol is presented for accessing quaternized α-amino acids in chiral, nonracemic form via diastereoselective malonate alkylation followed by C- to N-transposition. The key stereodifferentiating step involves a diastereoselective alkylation of an α-monosubstituted malonate-imidazolidinone, which is followed first by a chemoselective malonate PMB ester removal and then a Curtius rearrangement to provide the transposition. The method demonstrates a high product ee (89-99% for eight cases) for quaternizing a range of proteinogenic α-amino acids. The stereogenicity in targets 5a-i supports previous conclusions that the diastereoselective alkylation step proceeds via an α-substituted malonate-imidazolidinone enolate in its Z-configuration, with the auxiliary in an s-transC-N conformation.
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Affiliation(s)
- Maheswara Rao Gokada
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Roger Hunter
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Ana Andrijevic
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Wade F Petersen
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Sauvik Samanta
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Gerhard Venter
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Sophie Rees-Jones
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
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22
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Schörgenhumer J, Tiffner M, Waser M. Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles. Beilstein J Org Chem 2017; 13:1753-1769. [PMID: 28904619 PMCID: PMC5588627 DOI: 10.3762/bjoc.13.170] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 08/10/2017] [Indexed: 01/10/2023] Open
Abstract
Chiral phase-transfer catalysis is one of the major catalytic principles in asymmetric catalysis. A broad variety of different catalysts and their use for challenging applications have been reported over the last decades. Besides asymmetric C–C bond forming reactions the use of chiral phase-transfer catalysts for enantioselective α-heterofunctionalization reactions of prochiral nucleophiles became one of the most important field of application of this catalytic principle. Based on several highly spectacular recent reports, we thus wish to discuss some of the most important achievements in this field within the context of this review.
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Affiliation(s)
- Johannes Schörgenhumer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Maximilian Tiffner
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
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23
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Zhang YQ, Poppel C, Panfilova A, Bohle F, Grimme S, Gansäuer A. S N 2 Reactions at Tertiary Carbon Centers in Epoxides. Angew Chem Int Ed Engl 2017; 56:9719-9722. [PMID: 28608622 DOI: 10.1002/anie.201702882] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 06/08/2017] [Indexed: 11/09/2022]
Abstract
Described herein is a novel concept for SN 2 reactions at tertiary carbon centers in epoxides without activation of the leaving group. Quantum chemical calculations show why SN 2 reactions at tertiary carbon centers are proceeding in these systems. The reaction allows flexible synthesis of 1,3-diol building blocks for natural product synthesis with excellent control of the relative and absolute configurations.
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Affiliation(s)
- Yong-Qiang Zhang
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk Strasse 1, 53121, Bonn, Germany
| | - Christina Poppel
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk Strasse 1, 53121, Bonn, Germany
| | - Anastasia Panfilova
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk Strasse 1, 53121, Bonn, Germany
| | - Fabian Bohle
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische Chemie und Theoretische Chemie, Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische Chemie und Theoretische Chemie, Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard Domagk Strasse 1, 53121, Bonn, Germany
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24
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Zhang Y, Poppel C, Panfilova A, Bohle F, Grimme S, Gansäuer A. S
N
2 Reactions at Tertiary Carbon Centers in Epoxides. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201702882] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Yong‐Qiang Zhang
- Kekulé-Institut für Organische Chemie und BiochemieUniversität Bonn Gerhard Domagk Strasse 1 53121 Bonn Germany
| | - Christina Poppel
- Kekulé-Institut für Organische Chemie und BiochemieUniversität Bonn Gerhard Domagk Strasse 1 53121 Bonn Germany
| | - Anastasia Panfilova
- Kekulé-Institut für Organische Chemie und BiochemieUniversität Bonn Gerhard Domagk Strasse 1 53121 Bonn Germany
| | - Fabian Bohle
- Mulliken Center for Theoretical ChemistryInstitut für Physikalische Chemie und Theoretische ChemieUniversität Bonn Beringstrasse 4 53115 Bonn Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical ChemistryInstitut für Physikalische Chemie und Theoretische ChemieUniversität Bonn Beringstrasse 4 53115 Bonn Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und BiochemieUniversität Bonn Gerhard Domagk Strasse 1 53121 Bonn Germany
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25
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Gómez-Martínez M, Alonso DA, Pastor IM, Guillena G, Baeza A. Organocatalyzed Assembly of Chlorinated Quaternary Stereogenic Centers. ASIAN J ORG CHEM 2016. [DOI: 10.1002/ajoc.201600404] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Melania Gómez-Martínez
- Organic Chemistry Department and Organic Synthesis Institute; University of Alicante; Apdo. 99 E-03080- Alicante Spain
| | - Diego A. Alonso
- Organic Chemistry Department and Organic Synthesis Institute; University of Alicante; Apdo. 99 E-03080- Alicante Spain
| | - Isidro M. Pastor
- Organic Chemistry Department and Organic Synthesis Institute; University of Alicante; Apdo. 99 E-03080- Alicante Spain
| | - Gabriela Guillena
- Organic Chemistry Department and Organic Synthesis Institute; University of Alicante; Apdo. 99 E-03080- Alicante Spain
| | - Alejandro Baeza
- Organic Chemistry Department and Organic Synthesis Institute; University of Alicante; Apdo. 99 E-03080- Alicante Spain
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26
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Kennedy CR, Lin S, Jacobsen EN. The Cation-π Interaction in Small-Molecule Catalysis. Angew Chem Int Ed Engl 2016; 55:12596-624. [PMID: 27329991 PMCID: PMC5096794 DOI: 10.1002/anie.201600547] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Indexed: 11/11/2022]
Abstract
Catalysis by small molecules (≤1000 Da, 10(-9) m) that are capable of binding and activating substrates through attractive, noncovalent interactions has emerged as an important approach in organic and organometallic chemistry. While the canonical noncovalent interactions, including hydrogen bonding, ion pairing, and π stacking, have become mainstays of catalyst design, the cation-π interaction has been comparatively underutilized in this context since its discovery in the 1980s. However, like a hydrogen bond, the cation-π interaction exhibits a typical binding affinity of several kcal mol(-1) with substantial directionality. These properties render it attractive as a design element for the development of small-molecule catalysts, and in recent years, the catalysis community has begun to take advantage of these features, drawing inspiration from pioneering research in molecular recognition and structural biology. This Review surveys the burgeoning application of the cation-π interaction in catalysis.
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Affiliation(s)
- C Rose Kennedy
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA
| | - Song Lin
- Department of Chemistry, University of California, Berkeley, 535 Latimer Hall, Berkeley, CA, 94720, USA
| | - Eric N Jacobsen
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA.
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27
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Lehnherr D, Ford DD, Bendelsmith AJ, Kennedy CR, Jacobsen EN. Conformational Control of Chiral Amido-Thiourea Catalysts Enables Improved Activity and Enantioselectivity. Org Lett 2016; 18:3214-7. [PMID: 27294369 PMCID: PMC5096793 DOI: 10.1021/acs.orglett.6b01435] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
While aryl pyrrolidinoamido-thioureas derived from α-amino acids are effective catalysts in a number of asymmetric transformations, they exist as mixtures of slowly interconverting amide rotamers. Herein, the compromising role of amide bond isomerism is analyzed experimentally and computationally. A modified catalyst structure that exists almost exclusively as a single amide rotamer is introduced. This modification is shown to result in improved reactivity and enantioselectivity by minimizing competing reaction pathways.
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Affiliation(s)
- Dan Lehnherr
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - David D. Ford
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Andrew J. Bendelsmith
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - C. Rose Kennedy
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Eric N. Jacobsen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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28
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Pace WH, Mo D, Reidl TW, Wink DJ, Anderson LL. Catalytic Asymmetric Synthesis of Dihydropyrido[1,2‐
a
]indoles from Nitrones and Allenoates. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201602568] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Wiktoria H. Pace
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Dong‐Liang Mo
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Tyler W. Reidl
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Donald J. Wink
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Laura L. Anderson
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
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29
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Tayama E, Watanabe K, Matano Y. Ring-Strain Effects in Base-Induced Sommelet-Hauser Rearrangement: Application to Successive Stereocontrolled Transformations. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600611] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Eiji Tayama
- Department of Chemistry; Faculty of Science; Niigata University; 950-2181 Niigata Japan
| | - Kazutoshi Watanabe
- Department of Chemistry; Faculty of Science; Niigata University; 950-2181 Niigata Japan
| | - Yoshihiro Matano
- Department of Chemistry; Faculty of Science; Niigata University; 950-2181 Niigata Japan
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30
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Pace WH, Mo D, Reidl TW, Wink DJ, Anderson LL. Catalytic Asymmetric Synthesis of Dihydropyrido[1,2‐
a
]indoles from Nitrones and Allenoates. Angew Chem Int Ed Engl 2016; 55:9183-6. [PMID: 27346675 DOI: 10.1002/anie.201602568] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 05/01/2016] [Indexed: 12/29/2022]
Affiliation(s)
- Wiktoria H. Pace
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Dong‐Liang Mo
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Tyler W. Reidl
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Donald J. Wink
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
| | - Laura L. Anderson
- Department of Chemistry University of Illinois at Chicago 845 West Taylor Street Chicago IL 60607 USA
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31
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Kennedy CR, Lin S, Jacobsen EN. Die Kation-π-Wechselwirkung in der Katalyse mit niedermolekularen Verbindungen. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201600547] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- C. Rose Kennedy
- Department of Chemistry and Chemical Biology; Harvard University; 12 Oxford St Cambridge MA 02138 USA
| | - Song Lin
- Department of Chemistry; University of California, Berkeley; 535 Latimer Hall Berkeley CA 94720 USA
| | - Eric N. Jacobsen
- Department of Chemistry and Chemical Biology; Harvard University; 12 Oxford St Cambridge MA 02138 USA
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32
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Organocatalytic Asymmetric α-Chlorination of 1,3-Dicarbonyl Compounds Catalyzed by 2-Aminobenzimidazole Derivatives. Symmetry (Basel) 2016. [DOI: 10.3390/sym8010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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33
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Li JL, Yang KC, Li Y, Li Q, Zhu HP, Han B, Peng C, Zhi YG, Gou XJ. Asymmetric synthesis of bicyclic dihydropyrans via organocatalytic inverse-electron-demand oxo-Diels–Alder reactions of enolizable aliphatic aldehydes. Chem Commun (Camb) 2016; 52:10617-20. [DOI: 10.1039/c6cc05001h] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
An unprecedented highly enantioselective amine catalyzed oxo-IEDDA reaction of cyclic enones with enolizable aldehydes including aqueous acetaldehyde has been developed.
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Affiliation(s)
- Jun-Long Li
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province
- Sichuan Industrial Institute of Antibiotics
- Chengdu University
- Chengdu 610052
- P. R. China
| | - Kai-Chuan Yang
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province
- Sichuan Industrial Institute of Antibiotics
- Chengdu University
- Chengdu 610052
- P. R. China
| | - Yi Li
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province
- Sichuan Industrial Institute of Antibiotics
- Chengdu University
- Chengdu 610052
- P. R. China
| | - Qiang Li
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province
- Sichuan Industrial Institute of Antibiotics
- Chengdu University
- Chengdu 610052
- P. R. China
| | - Hong-Ping Zhu
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province
- Sichuan Industrial Institute of Antibiotics
- Chengdu University
- Chengdu 610052
- P. R. China
| | - Bo Han
- State Key Laboratory Breeding Base of Systematic Research
- Development and Utilization of Chinese Medicine Resources
- Chengdu University of Traditional Chinese Medicine
- Chengdu 611137
- China
| | - Cheng Peng
- State Key Laboratory Breeding Base of Systematic Research
- Development and Utilization of Chinese Medicine Resources
- Chengdu University of Traditional Chinese Medicine
- Chengdu 611137
- China
| | - Yong-Gang Zhi
- Chengdu Institute of Organic Chemistry
- Chinese Academy of Sciences
- Chengdu 610041
- China
| | - Xiao-Jun Gou
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province
- Sichuan Industrial Institute of Antibiotics
- Chengdu University
- Chengdu 610052
- P. R. China
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34
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Asymmetric α-chlorination of β-ketoesters using bifunctional ammonium salt catalysis. MONATSHEFTE FUR CHEMIE 2015. [DOI: 10.1007/s00706-015-1604-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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35
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Shibatomi K, Kotozaki M, Sasaki N, Fujisawa I, Iwasa S. Williamson Ether Synthesis with Phenols at a Tertiary Stereogenic Carbon: Formal Enantioselective Phenoxylation of β‐Keto Esters. Chemistry 2015; 21:14095-8. [DOI: 10.1002/chem.201502042] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Indexed: 01/13/2023]
Affiliation(s)
- Kazutaka Shibatomi
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1‐1 Hibarigaoka, Tempaku‐cho, Toyohashi, 441‐8580 (Japan)
| | - Manato Kotozaki
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1‐1 Hibarigaoka, Tempaku‐cho, Toyohashi, 441‐8580 (Japan)
| | - Nozomi Sasaki
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1‐1 Hibarigaoka, Tempaku‐cho, Toyohashi, 441‐8580 (Japan)
| | - Ikuhide Fujisawa
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1‐1 Hibarigaoka, Tempaku‐cho, Toyohashi, 441‐8580 (Japan)
| | - Seiji Iwasa
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1‐1 Hibarigaoka, Tempaku‐cho, Toyohashi, 441‐8580 (Japan)
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36
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Leonard MJ, McKay PG, Lingham AR. Bromo–nitro substitution on a tertiary α carbon—a previously uncharacterized facet of the Kornblum substitution. RSC Adv 2015. [DOI: 10.1039/c5ra14798k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Sodium nitrite in dimethylformamide substitutes nitro for bromine alpha to an amide carbonyl in high yield at a tertiary site.
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