Synthesis of 3-Formylindoles via Electrochemical Decarboxylation of Glyoxylic Acid with an Amine as a Dual Function Organocatalyst.

A new method for 3-formalytion of indoles has been developed through electrochemical decarboxylation of glyoxylic acid with the amine as a dual function organocatalyst. The amine facilitated both the electrochemical decarboxylation and the nucleophilic reaction efficiently, whose loading can be as low as 1 mol %. This protocol has a broad range of functional group tolerance under ambient conditions. The gram-scale experiment has shown great potential in the synthetic application of this strategy.