Direct catalytic enantioselective vinylogous aldol reaction of α-branched enals with isatins.
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.
ICIQ - Institute of Chemical Research of Catalonia, Av. Països Catalans 16, 43007 Tarragona, Spain.
Carlo
C
Cassani
Paolo
P
Melchiorre