Alternating current electrocatalytic asymmetric reductive coupling

Electrochemical asymmetric catalysis has emerged as a highly promising platform for the synthesis of high-value chiral molecules. Nevertheless, current advances in asymmetric electrochemical methods remain largely confined to direct current (DC) electrolysis, which suffers from intrinsic limitations such as chiral catalyst deposition and restricted mass transport of key chiral intermediates. Herein, we introduce alternating current (AC) electrolysis to asymmetric reductive coupling and demonstrate how waveform modulation can profoundly enhance stereoselective synthesis. This strategy enables the efficient production of chiral secondary alcohols with excellent enantioselectivity and diastereoselectivity (up to 98% e.e. and >20:1 d.r.). Detailed mechanistic studies and control experiments reveal that the inherent periodic polarity reversal in AC electrolysis effectively circumvents undesired reductive hydrogenation of aryl triflates while simultaneously preventing dissolution of non-inert electrodes.