Defluorinative C-C Bond-Forming Reaction of Trifluoromethyl Alkenes with gem -(Diborylalkyl)lithiums.

We report the transition-metal-free defluorinative C-C bond-forming reaction of trifluoromethyl alkenes with gem -(diborylalkyl)lithiums. This synthetic strategy provides access to a variety of 4,4-difluoro homoallylic diboronate esters, which serve as versatile intermediates in the efficient preparation of valuable gem -difluoroalkene derivatives. Further synthetic modifications are conducted to demonstrate the synthetic utility of the obtained 4,4-difluoro homoallylic diboronate esters.