Asymmetric Alternating‐Current Electrolysis for Deoxygenation of Benzylic Alcohols With Suppressed Anode Consumption

ABSTRACT

Sacrificial anodes in conventional direct current electrolysis suffer from rapid and irreversible consumption, limiting sustainability in reductive electrosynthesis. Herein, we report an asymmetric alternating current (AC) electrolysis protocol that enables direct deoxygenation of benzylic alcohols and related carbonyl compounds using water as the hydrogen source. By operating at 10 V, a potential that causes rapid anode failure under DC, the asymmetric waveform leverages periodic polarity reversal to partially recover anodically leached Zn ²⁺ ions at the electrode surface and limit anode weight loss to approximately 5% per cycle. The method exhibits broad substrate scope, good functional group tolerance, and excellent chemoselectivity for benzylic C─O bonds. The protocol is also compatible with D ₂ O, affording α‐deuterated methylarenes with high isotope incorporation (typically over 90%). Mechanistic studies support a radical pathway in which Zn ²⁺ facilitates the initial electron transfer.