BPO-promoted [4 + 2] cyclization of enaminones and o -phenylenediamines to 2-acyl quinoxalines via a cascade transamination and C-H amination.

Rapid assembly of quinoxalines in a single step from readily available precursors has been recognized as an ideal platform in terms of efficiency and operation. Herein, we report a BPO-promoted metal-free approach to 2-acyl quinoxalines from enaminones and o -phenylenediamines via cascade transamination and C-H amination. This methodology demonstrates excellent compatibility with various substrates, including o -hydroxy enaminones, drug derivatives and natural products under mild reaction conditions.