Enantioselective vinylogous aldol reaction between β,γ-unsaturated amides and isatins†
Abstract
A catalytic asymmetric vinylogous aldol reaction between β,γ-unsaturated amides and isatins has been developed. In the presence of 10 mol% of tertiary amine-thiourea C7, the vinylogous reaction has been achieved in up to 98% yield and up to 99% ee (26 examples). This methodology provides an efficient approach to construct chiral multifunctional 3-hydroxy-2-oxindoles. Moreover, the transformations of the chiral products, including the esterification of amides, the hydrogenation of the C–C double bond and further conversion to spirolactones, have been investigated.