Direct Catalytic Enantioselective Vinylogous Aldol Reaction of α‑Branched Enals with Isatins
journal contributionposted on 02.11.2012, 00:00 by Carlo Cassani, Paolo Melchiorre
The direct vinylogous aldol reaction of α-substituted α,β-unsaturated aldehydes with isatins is described. The chemistry provides easy access to valuable 3-substituted 3-hydroxyoxindole derivatives with high stereocontrol and perfect γ-site selectivity. Preliminary mechanistic studies suggest that, depending on the nature of the α-branched enal substituents, two divergent reaction mechanisms can be operating, leading to different products and stereochemical outcomes.