Metal-Free C–C Cross Coupling: Electrosynthesis of Azaheterocycles through Anodic Oxidation Cyclization of 1,6-Enynes

A straightforward synthesis of azaheterocycles
has been developed
through electrochemically aerobic oxidation cyclization using a user-friendly
undivided electrolytic cell at room temperature under catalyst-free
conditions. This green and practical electrosynthesis strategy features
good functional group, diverse electronic and steric properties tolerance.
On the basis of a series of mechanistic investigations, including
isotope labeling, singlet oxygen inhibiting, superoxide radical anion
inhibiting, radical-trapping, cyclic voltammetry and controlled potential
electrolysis experiments, a possible N-centered radical-initiated
mechanism was proposed.