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 pTolSO(2)) 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.