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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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Goud SB, Guin S, Prakash M, Samanta S. Cu(OAc) 2/DABCO-mediated domino reaction of vinyl malononitriles with cyclic sulfamidate imines: access to 6-hydroxyaryl-2-aminonicotinonitriles. Org Biomol Chem 2022; 20:352-357. [PMID: 34931209 DOI: 10.1039/d1ob02095a] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A novel Cu(II)-salt/DABCO-mediated one-pot access to a myriad of highly substituted biologically relevant 2-aminonicotinonitriles possessing a resourceful phenolic moiety with satisfactory yields is reported. This method involves cyclic sulfamidate imines as 1C1N sources and different kinds of acyclic/cyclic vinyl malononitriles as 4C sources for pyridine synthesis via a vinylogous Mannich-cycloaromatization sequence process, creating two new C-N bonds under mild conditions. Importantly, this de novo strategy is applicable to gram-scale syntheses, underlining the method's practicability and allowing for a wide range of substrates with excellent functional group tolerance.
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Affiliation(s)
- S Banuprakash Goud
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, 453552 India.
| | - Soumitra Guin
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, 453552 India.
| | - Meher Prakash
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, 453552 India.
| | - Sampak Samanta
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, 453552 India.
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Vinylogous and Arylogous Stereoselective Base-Promoted Phase-Transfer Catalysis. Catalysts 2021. [DOI: 10.3390/catal11121545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Vinylogous enolate and enolate-type carbanions, generated by deprotonation of α,β-unsaturated compounds and characterized by delocalization of the negative charge over two or more carbon atoms, are extensively used in organic synthesis, enabling functionalization and C–C bond formation at remote positions. Similarly, reactions with electrophiles at benzylic and heterobenzylic position are performed through generation of arylogous and heteroarylogous enolate-type nucleophiles. Although widely exploited in metal-catalysis and organocatalysis, it is only in recent years that the vinylogy and arylogy principles have been translated fruitfully in phase-transfer catalyzed processes. This review provides an overview of the methods developed to date, involving vinylogous and (hetero)arylogous carbon nucleophiles under phase-transfer catalytic conditions, highlighting main mechanistic aspects.
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