S-Aryl Arenesulfonothioate and Copper Acetate Mediated Arylthiolation of 2-Arylpyridines and Heteroarenes.

Copper acetate mediated regioselective ortho-arylthiolation of 2-arylpyridines has been accomplished for the first time using S-aryl arenesulfonothioate as the arylthiolating agent. The reaction shows good functional group tolerance and gives thioarylated products in 67-89% yields. This reagent is a good alternative to unpleasant smelling arylthiols. Experimental evidence suggests an unprecedented insertion of an arylthio unit from both parts of the reagent (SPh and p-TolSO2) in the presence of copper acetate. Indoles and imidazopyridines also undergo facile reaction at the C-3 position and furnish thioarylated derivatives in good yields.