Copper-Mediated Regioselective C-H Sulfenylation and Selenation of Phenols with Phenanthroline Bidentate Auxiliary.

A copper-mediated, phenanthroline-directed highly ortho-selective C-H sulfenylation of phenols with diaryl disulfides proceeds to form the corresponding unsymmetrical diaryl sulfides in good yield. The key to success is the introduction of a phenanthroline directing group of the bidentate-chelating nature, which is easily attachable, detachable, and even recyclable. Moreover, the same strategy is applicable to the C-H selenation, giving the diaryl selenides with high efficiency and regioselectivity.