Highly Selective C-F Bond Functionalization of Tetrasubstituted gem -Difluoroalkenes and Trisubstituted Monofluoroalkenes Using Grignard Reagents.

We herein describe selective C-F bond functionalizations of tetrasubstituted gem -difluoroalkenes and trisubstituted monofluoroalkenes using Grignard reagents without the transition metal catalyst. β,β-Difluoroacrylates react with Grignard reagents under mild conditions to afford tetrasubstituted ( E )-β-monofluoroacrylates. Experimental and computational studies revealed that the selectivity stems from the intrinsic reactivity difference between the ( E )- and ( Z )-isomers toward excess Grignard reagent, which leads to the resolution of the two products.