Electrochemical multi-component reaction of potassium metabisulfite with alkenes and alcohols enabling synthesis of sulfonate esters

Abstract

Sulfonate esters are privileged structures in medicinal chemistry and also exist in many natural products. Here we have developed an efficient electrochemical transition-metal-free strategy for the difunctionalization of alkenes to construct β-alkoxyl sulfonate esters through C–S, S–O, and C–O bond formation. This reaction uses potassium metabisulfite as the sulfur dioxide surrogate under electrochemical conditions for the first time. This strategy features mild reaction conditions, easy-to-handle reactants, and good chemical yields. The mechanistic investigation suggests that this reaction proceeds through the formation of a sulfur dioxide radical cation, sulfonylation of alkene, and dual couplings with alcohol. This finding not only enriches the research contents of the metabisulfite salt but also provides a green and easy access to sulfonate esters compared with existing methodologies.