Electrochemical difunctionalization of indolizines with glyoxylic acid and halide salts

Abstract

A novel and sequential strategy for the synthesis of C3-formylated and C1-halogenated indolizines through electrochemical difunctionalization has been developed. This protocol proceeds smoothly without external oxidants or catalysts, and exhibits excellent functional group tolerance. A series of disubstituted indolizines are obtained under mild conditions (yield up to 81%). Scale-up reaction and further transformation of the product can confirm the practicality of this protocol. The developed process has been evaluated using green metrics to validate its sustainability. A possible mechanism for regioselective C–H formylation and halogenation of indolizines is elucidated by control experiments and cyclic voltammetry studies.