Duan J, Xiong Z, Zhou Y, Yao W, Li X, Zhang M, Wang Z. Access to Chiral Chromenones through Organocatalyzed Mannich/Annulation Sequence.
Org Lett 2021;
23:8007-8012. [PMID:
34606286 DOI:
10.1021/acs.orglett.1c03010]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein we report an efficient and practical method to access chiral chromenones bearing one α-amino stereogenic center in the β position of the carbonyl group. The quinine-derived squaramide could efficiently promote Mannich/cycloketalization/dehydration tandem reactions between 1-(2-hydroxyaryl)-1,3-diketones and functionalized imines generated in situ, providing a wide range of chiral chromenones with propargylamine or α-amino ester moieties with good results (54 examples, up to 98% ee).
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