Asymmetric synthesis of 3-benzyl and allyl isoindolinones by Pd-catalyzed dicarbofunctionalization of 1,1-disubstituted enamides

Abstract

Enantioenriched isoindolinones represent a valuable heterocycle motif, widely found in pharmaceuticals and biologically active natural products. We herein report a palladium-catalyzed asymmetric synthesis of 3,3-disubstituted isoindolinones via the tandem Heck/Suzuki coupling of 1,1-disubstituted enamides with aryl/alkenyl boronic acids under mild reaction conditions. This reaction exhibits both broad functional group tolerance and high enantioselectivity. We report the first dicarbo-functionalization of 1,1-disubstituted enamides to generate amide derivatives bearing quaternary stereocenters. Finally, the synthetic utility of this protocol is demonstrated by the expedient synthesis of the PI3K-delta inhibitor precursor.