Electrosynthesis of Chlorohydrins From Alkenes in Seawater Enabled by On‐Site Generated Active Surface Chlorine Intermediate

Abstract

ABSTRACT Chlorohydrins are essential intermediates in organic synthesis, playing a critical role in drug discovery, green catalysis, and bioactive molecule manufacturing. However, conventional chlorohydrin synthesis usually requires harsh conditions, which create safety risks and poor selectivity. Here we develop a direct and efficient electrocatalytic strategy for synthesizing chlorohydrins from commodity alkenes, which are globally produced at over 200 million metric tons annually. Utilizing a RuSnNbO x polymetallic oxide catalyst, cyclohexene is directly converted to 2‐chlorocyclohexanol in NaCl solution with a Faradaic efficiency of 96.1 ± 3% and selectivity of 98.2 ± 0.4% at 1.6 V versus reversible hydrogen electrode. This approach is generalizable to other alkenes, such as styrene and cyclopentene, yielding 2‐chloro‐1‐phenylethanol and 2‐chlorocyclopentanol with uncompromised Faradaic efficiency. Mechanistic investigations reveal that the adsorbed active chlorine species, electrogenerated via Cl − oxidation on the RuSnNbO x anode, serve as key intermediates for direct alkene chlorination. Notably, this electrosynthesis method is further upscaled to gram‐level in acidic seawater, delivering 3.01 g of 2‐chlorocyclohexanol and 0.87 g of 2‐chloro‐1‐phenylethanol. This work provides a sustainable and scalable alternative to conventional chlorohydrin production and offers insights into designing efficient electrolysis for related transformations.