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Zhao M, Zhao Z, Wei Z, Cao J, Liang D, Lin Y, Duan H. Asymmetric Mannich Reaction of Isatin-Derived Ketimines with α-Fluoroindanones Catalyzed by a Chiral Phase-Transfer Catalyst. J Org Chem 2024; 89:4474-4483. [PMID: 38506434 DOI: 10.1021/acs.joc.3c02668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
A highly enantioselective Mannich reaction of α-fluoroindanones with isatin-derived N-Boc-ketimines catalyzed by a quinine-derived phase-transfer catalyst was developed. A variety of 3-substituted 3-amino-2-oxindoles bearing fluorine-containing, vicinal, tetrasubstituted stereocenters were constructed using this protocol in high yields (83-95%), with moderate to excellent enantioselectivities (66-91%) and high diastereoselectivities (up to >99:1).
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Affiliation(s)
- Meiyan Zhao
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Zhiqi Zhao
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Zhonglin Wei
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Jungang Cao
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Dapeng Liang
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Yingjie Lin
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Haifeng Duan
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
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Niedbała P, Majdecki M, Grodek P, Jurczak J. H-Bond Mediated Phase-Transfer Catalysis: Enantioselective Generating of Quaternary Stereogenic Centers in β-Keto Esters. Molecules 2022; 27:molecules27082508. [PMID: 35458707 PMCID: PMC9024675 DOI: 10.3390/molecules27082508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 02/01/2023] Open
Abstract
In this work, we would like to present the development of a highly optimized method for generating the quaternary stereogenic centers in β-keto esters. This enantioselective phase-transfer alkylation catalyzed by hybrid Cinchona catalysts allows for the efficient generation of the optically active products with excellent enantioselectivity, using only 1 mol% of the catalyst. The vast majority of phase-transfer catalysts in asymmetric synthesis work by creating ionic pairs with the nucleophile-attacking anionic substrate. Therefore, it is a sensible approach to search for new methodologies capable of introducing functional groups into the precursor’s structure, maintaining high yields and enantiomeric purity.
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Li J, Wei Z, Cao J, Liang D, Lin Y, Duan H. Aymmetric Aza-Friedel-Crafts Reaction of Isatin-Derived Ketimines with Indoles Catalyzed by a Chiral Phase-Transfer Catalyst. J Org Chem 2022; 87:2532-2542. [PMID: 35084194 DOI: 10.1021/acs.joc.1c02477] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A highly enantioselective aza-Friedel-Crafts reaction of 1H-indoles with isatin-derived N-Cbz-ketimines catalyzed by quinine-derived phase-transfer catalysts was developed. A series of chiral 3-aminobisindole compounds containing a tetrasubstituted stereocenter were constructed by this protocol in high yields (82-91%) and moderate to excellent enantioselectivities (46-94% ee).
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Affiliation(s)
- Jing Li
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Zhonglin Wei
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Jungang Cao
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Dapeng Liang
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Yingjie Lin
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
| | - Haifeng Duan
- Department of Organic Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China
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Litvajova M, Sorrentino E, Twamley B, Connon SJ. Base-free enantioselective S N2 alkylation of 2-oxindoles via bifunctional phase-transfer catalysis. Beilstein J Org Chem 2021; 17:2287-2294. [PMID: 34621391 PMCID: PMC8450950 DOI: 10.3762/bjoc.17.146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/18/2021] [Indexed: 11/23/2022] Open
Abstract
N-Protected oxindole derivatives of unprecedented malleability bearing ester moieties at C-3 have been shown to participate in enantioselective phase-transfer-catalysed alkylations promoted by ad-hoc designed quaternary ammonium salts derived from quinine bearing hydrogen-bond donating substituents. For the first time in such phase-transfer-catalysed enolate alkylations, the reactions were carried out under base-free conditions. It was found that urea-based catalysts outperformed squaramide derivatives, and that the installation of a chlorine atom adjacent to the catalyst’s quinoline moiety aided in avoiding selectivity-reducing complications related to the production of HBr in these processes. The influence of steric and electronic factors from both the perspective of the nucleophile and electrophile were investigated and levels of enantiocontrol up to 90% ee obtained. The synthetic utility of the methodology was demonstrated via the concise enantioselective synthesis of a potent CRTH2 receptor antagonist.
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Affiliation(s)
- Mili Litvajova
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Emiliano Sorrentino
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Brendan Twamley
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Stephen J Connon
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
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Duan H, Lin Y, Zhao Z, Wang J, Wei Z, Cao J, Liang D. Asymmetric Synthesis of 3-Phenyl-2,3-dihydro-1H-pyrrolo[3,2-b]pyridine-3-carbonitriles Catalyzed by Phase-Transfer Catalyst Derived from tert-Leucine. Synlett 2021. [DOI: 10.1055/a-1581-2345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractChiral phase-transfer catalysts derived from tert-leucine were synthesized and used in the asymmetric synthesis of 4-azaindoline derivatives. By this method, both enantiomers of the corresponding products were obtained in excellent yield (up to 99%) with high enantioselectivities (up to 91% ee) and diastereoselectivities (up to >99: 1 dr).
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Jurczak J, Majdecki M, Niedbała P, Tyszka-Gumkowska A. Assisted by Hydrogen-Bond Donors: Cinchona Quaternary Salts as Privileged Chiral Catalysts for Phase-Transfer Reactions. SYNTHESIS-STUTTGART 2021. [DOI: 10.1055/a-1472-7999] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
AbstractThis short review is devoted to asymmetric phase-transfer reactions that employ hybrid ammonium Cinchona catalysts supported by possessing hydrogen-bond donor groups. We present recent advances utilizing this type of catalyst in the field of biphasic reaction systems. The main emphasis is placed on the advantages of additional functional groups present in the structure of the catalyst, such as hydroxy, amide, (thio)urea or squaramide.1 Introduction2 Phase-Transfer Hybrid Cinchona Catalysts with a Free Hydroxy Group3 (Thio)urea Hybrid Cinchona Catalysts4 Hybrid Amide-Based Catalysts Bearing a Cinchona Scaffold5 Conclusions
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Stead D. The diastereoselective synthesis of 2,3-diaryl-3-cyano-substituted pyrrolidines via the MgI2 mediated ring expansion of aryl cyclopropyl nitriles. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.152325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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