Electrochemical Three-component Synthesis of Alkenesulfonates from Cinnamic Acids, SO2, and Alcohols.

A novel, electrochemical three-component reaction for the synthesis of alkyl alkenesulfonates from cinnamic acids, SO2, and alkyl alcohols is reported. This metal-free process employs inexpensive and readily available graphite electrodes in combination with easy-to-use stock solutions of SO2 and enables a straightforward construction of the styrene sulfonate scaffold via a decarboxylative transformation. Mechanistic studies indicate a pseudo-Kolbe type reaction. This novel reaction pathway enables a regioselective synthesis of alkenesulfonates from substituted cinnamic acids without double-bond translocation. Gram-scale and anolyte reusability experiments demonstrate the applicability of this process for the construction of alkenesulfonates from cinnamic acids as potential biogenic feedstock.