Synthesis of -Tosyloxylated gem-Difluoroalkanes via Elusive [2,3]-Sulfonyloxy Migration

gem-Difluoroalkanes widely exist in pharmaceuticals, agrochemicals and materials. Reported herein is a facile synthesis of tosyloxylated gem-difluoroalkanes via an oxidative fluorination of readily available vinyl sulfonates. An intriguing [2,3]-sulfonyloxy migration, which has been rarely known, is involved as a key step. The OTs group within the products enables a divergent and modular synthesis of a wide variety of functionalized gem-difluoroalkanes via simple and reliable SN2 reactions. Notable features of this protocol include mild reaction conditions, high efficiency and remarkably good functional group tolerance. Theoretical mechanistic studies were conducted, supporting a rate-determining [2,3]-sulfonyloxy shift is involved.