Palladium-Catalyzed Stereoselective C-F Bond Vinylation and Allylation of Tetrasubstituted gem-Difluoroalkenes via Stille Coupling: Synthesis of Monofluorinated 1,3- and 1,4-Dienes.

We herein describe a Pd-catalyzed stereoselective C-F bond vinylation and allylation reaction of tetrasubstituted gem-difluoroalkenes for the synthesis of valuable monofluorinated 1,3- and 1,4-dienes with excellent diastereoselectivities. Different from previously used Pd(PPh3)4, a catalytic system involving Pd(0) and dppe as the ligand was developed for Stille-type cross-coupling between gem-difluoroalkenes and vinyl- and allyltin reagents.