Rhodium-catalyzed asymmetric hydroamination of gem-difluoroallenes with anilines

A rhodium-catalyzed protocol has been established for the enantioselective hydroamination of gem-difluoroallenes with anilines. This strategy shows complete atom-efficiency to access a variety of enantioenriched gem-difluoroallylic amines in excellent branched selectivity (>99:1 for each case), which are important backbones in many biologically active compounds. Mechanistic studies suggest the generation of a gem-difluoro π-allyl rhodium intermediate by an exclusive hydrometalation pathway, which undergoes nucleophilic substitution of amines.