Synthesis of Functionalized Isoquinolone Derivatives via Rh(III)-Catalyzed [4+2]-Annulation of Benzamides with Internal Acetylene-Containing α-CF 3 -α-Amino Carboxylates.

A convenient pathway to a new series of α-CF 3 -substituted α-amino acid derivatives bearing pharmacophore isoquinolone core in their backbone has been developed. The method is based on [4+2]-annulation of N- (pivaloyloxy) aryl amides with orthogonally protected internal acetylene-containing α-amino carboxylates under Rh(III)-catalysis. The target annulation products can be easily transformed into valuable isoquinoline derivatives via a successive aromatization/cross-coupling operation.