A Continuous Flow Process for the Defluorosilylation of HFC-23 and HFO-1234yf

A continuous flow process has been developed for the defluorosilylation of trifluoromethane (HFC-23) and 2,3,3,3-propene (HFO-1234yf) through reaction with lithium silanide reagents under inert conditions. Design of experiment optimization improved process conditions including productivity, yields, reduction of solvent use, and gas destruction. The small chain fluorinated organosilane products R3SiCF2H and R3SiCH2C(F)=CF2 were competent nucleophiles in the fluoride-catalyzed difluoromethylation of aldehydes, and trifluoroallylation of aldehydes, ketones, and imines. Stepwise treatment of R3SiCH2C(F)=CF2 with KHMDS and IPrCuCl gave IPrCuCC–CF2H, which reacted with allyl and acyl halides to transfer the fluorinated propyne motif.