Ghosh B, Balhara R, Jindal G, Mukherjee S. Catalytic Enantioselective Desymmetrizing Fischer Indolization through Dynamic Kinetic Resolution.
Angew Chem Int Ed Engl 2021;
60:9086-9092. [PMID:
33555647 DOI:
10.1002/anie.202017268]
[Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Indexed: 12/14/2022]
Abstract
The first catalytic enantioselective Fischer indolization of prochiral diketones containing enantiotopic carbonyl groups is developed and shown to proceed through dynamic kinetic resolution (DKR). Catalyzed by the combination of a spirocyclic chiral phosphoric acid and ZnCl2 (Lewis acid assisted Brønsted acid), this direct approach combines 2,2-disubstituted cyclopentane-1,3-diones with N-protected phenylhydrazines to furnish cyclopenta[b]indole derivatives containing an all-carbon quaternary stereocenter with good to excellent enantioselectivities.
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