Copper-catalyzed benzylic C–H bond thiocyanation: Enabling late-stage diversifications

Abstract

The rapid growth of using C–H bond as cross-coupling partners is reshaping the landscape of organic synthesis. C(sp3)–H functionalization via hydrogen atom transfer (HAT) represents the most compelling strategy in this avenue. Here, we demonstrate an efficient method for benzylic C–H bond thiocyanation via copper-catalyzed radical relay. The reaction exhibits broad substrate scope and exquisite benzylic selectivity with C–H substrates as limiting reagents. In addition, the benzyl thiocyanates are readily converted to other pharmaceutically important motifs, including isothiocyanate, thiourea, and others, highlighting the broad utility of this method.