Gem-Difluoroallylation of Aryl Sulfonium Salts.

The unprecedented photochemical late-stage defluorinative gem-difluoroallylation of aryl sulfonium salts, which are formed site-selectively by direct C(sp 2 )─H functionalization, is herein disclosed. This method is distinguished by its mild reaction conditions, wide scope, and excellent site-selectivity. As showcase examples, a Flurbiprofen and Pyriproxyfen derivatives could be late stage C(sp 2 )─H gem-difluoroallylated with high yields. Experimental and computational investigations were conducted.