Transition-metal-catalyzed Electrophilic Activation of 1,1-Difluoro-1-alkenes: Oxindole Synthesis via Intramolecular Amination

Abstract

Abstract In the presence of a catalytic amount of palladium(II) chloride, β,β-difluorostyrenes bearing a sulfonamido group at the ortho position were treated with trimethylsilyl trifluoromethanesulfonate to afford oxindoles in high yield. The reactions proceeded via 5-endo-trig cyclization, hydrolysis, and desulfonylation. This sequence allowed the transformation of difluorostyrenes into free oxindoles in a one-pot operation.