Tang M, Gu H, He S, Rajkumar S, Yang X. Asymmetric Enamide-Imine Tautomerism in the Kinetic Resolution of Tertiary Alcohols.
Angew Chem Int Ed Engl 2021;
60:21334-21339. [PMID:
34312956 DOI:
10.1002/anie.202106151]
[Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Indexed: 12/23/2022]
Abstract
An efficient protocol for kinetic resolution of tertiary alcohols has been developed through an unprecedented asymmetric enamide-imine tautomerism process enabled by chiral phosphoric acid catalysis. A broad range of racemic 2-arylsulfonamido tertiary allyl alcohols could be kinetically resolved with excellent kinetic resolution performances (with s-factor up to >200). This method is particularly effective for a series of 1,1-dialkyl substituted allyl alcohols, which produced chiral tertiary alcohols that would be difficult to access via other asymmetric methods. Facile and versatile transformations of the chiral α-hydroxy imine and enamide products, especially the efficient stereodivergent synthesis of all four stereoisomers of β-amino tertiary alcohols using one enantiomer of the catalyst, demonstrated the value of this kinetic resolution method.
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