Site-selective electrochemical thiocyanation of benzylic C-H bonds

Direct benzylic C(sp(3))-H thiocyanation is explored as a straightforward strategy toward the synthesis of thiocyanate derivatives. We report herein an electrochemical protocol for site-selective benzylic C(sp(3))-H thiocyanation under mild reaction conditions. The reaction demonstrates broad substrate scope and unique benzylic C-H site selectivity (2 degrees > 3 degrees > 1 degrees) over the existing methods. Preliminary mechanistic studies indicate that the reaction probably undergoes a radical-polar crossover process. This method is also successfully used for follow-up transformation and late-stage thiocyanation of bioactive molecules.