Selective electrochemical oxidation of tetrahydroquinolines to 3,4-dihydroquinolones

Abstract

We report an environmentally friendly electrochemical oxidation of tetrahydroquinolines to 3,4-dihydroquinolones. The reaction uses electricity as a “traceless” oxidant, O₂ as a “green” oxygen source, and 2,2,6,6-tetramethylpiperidinooxy (TEMPO) as a redox mediator. NaI not only acts as an electrolyte, but may also act as a redox mediator. The reaction shows high selectivity and good functional group tolerance.