Organocatalytic Enantioselective Michael-Michael-Michael-Aldol Condensation Reactions: Control of Six Stereocenters in a Quadruple-Cascade Asymmetric Synthesis of Polysubstituted Spirocyclic Oxindoles
Chaudhari, P.D.; Hong, B.-C.; Lee, G.-H.
Organic Letters 19(22): 6112-6115
2017
ISSN/ISBN: 1523-7052
PMID: 29090937
DOI: 10.1021/acs.orglett.7b02962
Accession: 060052645
An organocatalyzed enantioselective Michael-Michael-Michael-aldol cascade reaction for the construction of cyclopentane fused spirooxindoles was achieved. The domino reaction provided the spirooxindoles with six contiguous stereocenters including a quaternary center in good yields (55-64%) with excellent enantioselectivities (up to >99% ee). Enantioselective Michael-Michael-Michael-aldol condensation-aromatization reactions of an isomeric product were observed.