Cao J, Su YX, Zhang XY, Zhu SF. Highly Enantioselective Brønsted Acid Catalyzed Heyns Rearrangement.
Angew Chem Int Ed Engl 2023;
62:e202212976. [PMID:
36316277 DOI:
10.1002/anie.202212976]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Indexed: 12/05/2022]
Abstract
Herein we report the first method for highly enantioselective Brønsted acid catalyzed Heyns rearrangements. These reactions, catalyzed by a chiral spiro phosphoric acid, afforded synthetically valuable chiral α-aryl-α-aminoketones which cannot be obtained by means of previously reported Heyns rearrangement methods. This method features low catalyst loadings, high yields and high enantioselectivities, making these reactions highly practical. We used the method to efficiently synthesize various chiral amines, including some biologically active molecules. We experimentally proved that these acid-catalyzed Heyns rearrangements proceeded via a proton-transfer process involving an enol intermediate and the stereocontrol was realized during the proton-transfer step.
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