Photoredox-catalyzed direct deoxygenative coupling of alcohols to thioethers under batch and flow conditions.

Abstract

Sulfur-containing compounds, particularly thioethers, are of significant value in the pharmaceutical, agrochemical, and functional materials industries. Traditional methods for constructing C-S bonds are often constrained by harsh reaction conditions and limited substrate scope. Alcohols represent the most abundant and structurally diverse class of alkyl sources; converting them into sulfur-containing compounds could greatly enrich the structural diversity of the latter, yet systematic studies in this direction remain scarce. Herein, we report an NHC-assisted photoredox catalytic strategy that enables the deoxygenative coupling of primary and secondary alcohols, as well as sugar derivatives, with disulfides or benzenesulfonyl peroxydithioates, affording thioethers and disulfides in a straightforward manner. This protocol accommodates both aliphatic and aromatic disulfides and can be efficiently scaled up in a microflow reactor. By transforming structurally diverse alcohols into versatile alkyl radical precursors, this approach opens up new avenues for the functionalization of alcohols and holds promise for industrial translation.