Han Z, Zhu B, Zang Y, Zhang C, Dong XQ, Huang H, Sun J. Primary activation of
para-quinone methides by chiral phosphoric acid for enantioselective construction of tetraarylmethanes.
Chem Sci 2024;
15:720-725. [PMID:
38179542 PMCID:
PMC10763553 DOI:
10.1039/d3sc05014a]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 11/21/2023] [Indexed: 01/06/2024] Open
Abstract
Demonstrated here is an asymmetric nucleophilic addition via primary activation of para-quinone methides (p-QMs) based on a chiral phosphoric acid catalytic system. In sharp contrast to previous CPA-based bifunctional activation processes that all required the nucleophiles to have an effective hydrogen bond donor unit (e.g., OH, NH), here no such unit is required in the nucleophile. N-protected indole nucleophiles were successfully utilized for the synthesis of chiral tetraarylmethanes with high efficiency and enantioselectivity under mild conditions. Therefore, this protocol significantly expanded the scope of asymmetric transformations of p-QMs.
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