Copper-mediated direct sulfonylation of C(sp2)–H bonds employing TosMIC as a sulfonyl source
A method for Cu-mediated direct ortho-C–H sulfonylation of benzoic acid derivatives was developed by employing a PyO-directing group. For the first time, TosMIC could act as a sulfonyl source instead of sulfonyl chlorides or sulfinate salts. This protocol featured cheap metal catalysis, broad functional group compatibility and easy handling nature. Moreover, the PyO-directing group could be efficiently removed in one step.