Cobalt-Catalyzed Fluoroallyllation of Carbonyls via C-C Activation of gem -Difluorocyclopropanes.

A new Co-catalyzed sequential C-C and C-F activation of gem -difluorinated cyclopropanes ( gem -FCPs) to form nucleophilic fluoroallylcobalt, followed by addition to aldehydes, is reported. The protocol features the regioselective cleavage of dual chemical bonds of readily available gem -FCPs to prepare easily separable linear ( Z )- and ( E )-fluorinated homoallylic alcohols with a broad scope. This discovery established a new strategy for the efficient transformation of gem -FCPs as well as the synthesis of challenging fluorinated homoallylic alcohols.