Copper-Mediated One-Pot Synthesis of 2,2-Difluoro-1,3-benzoxathioles from o-Bromophenols and Trifluoromethanethiolate.

A copper-mediated difluoromethylenation of o-bromophenols with trifluoromethanethiolate is described. This one-pot protocol proceeds through an intermolecular addition of S=CF (resulting from the decomposition of trifluoromethanethiolate) to o-bromophenols followed by intramolecular C-S coupling to form 2,2-difluoro-1,3-benzoxathioles. This method is compatible with a broad range of substrates and enables the late-stage difluoromethylenation of several functionally dense druglike o-bromophenols.