Electrochemical synthesis of hydroxyalkylated quinoxalines via C-H functionalization.

An efficient electrochemical C-H hydroxyalkylation of quinoxalines with aldehydes and ketones has been developed in an undivided cell. A variety of aliphatic and aromatic aldehydes as well as ketones have been examined, affording the corresponding hydroxyalkylated quinoxalines in good yields. Mechanism investigations indicate that the hydroxyalkylation is achieved through cathodic reduction to produce ketyl radicals and heteroaryl radical anions, followed by radical-radical cross-coupling.