Switchable Access to Different Spirocyclopentane Oxindoles by N-Heterocyclic Carbene Catalyzed Reactions of Isatin-Derived Enals and N-Sulfonyl Ketimines



: Wang L, Li S, Blumel M, Puttreddy R, Peuronen A, Rissanen K, Enders D

Publisher: WILEY-V C H VERLAG GMBH

: 2017

: Angewandte Chemie International Edition

: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

: ANGEW CHEM INT EDIT

: 56

: 29

: 8516

: 8521

: 6

: 1433-7851

DOI: https://doi.org/10.1002/anie.201704210


A novel NHC-catalyzed annulation protocol for the asymmetric synthesis of biologically important beta-lactam fused spirocyclopentane oxindoles with four contiguous stereocenters, including two quaternary carbon centers, was developed. Alternatively, spirocyclopentane oxindoles containing an enaminone moiety can be achieved using the same starting materials, isatin-derived enals, and N-sulfonyl ketimines, in the presence of a slightly different NHC catalytic system. This switchable annulation strategy enables the selective assembly of both heterocyclic scaffolds with good yields and excellent enantioselectivities for a broad range of substrates.



Last updated on 2024-26-11 at 14:46