Multicomponent Electrosynthesis of Enaminyl Sulfonates Starting from Alkylamines, SO$_2$, and Alcohols

An electrochemical one-pot synthesis of enaminyl sulfonate esters was established, featuring a quasidivided cell under constant current conditions. The multicomponent reaction utilizes simple and readily available alkylamines and an easy-to-use stock solution of SO$_2$ and alcohols. Omission of additional supporting electrolyte through in-situ-generated monoalkylsulfite facilitates the downstream processing. A diverse scope with more than 28 examples and yields up to 85% as well as a 20-fold scale-up reaction prove the feasibility of this novel protocol.