Green and modular synthesis of azepino[4,3,2-cd]indoles and diazepino[6,5,4-cd]indoles via hydride transfer-involved cascade cyclization in ethanol

A green and modular synthesis of azepino[4,3,2- cd ]indoles and diazepino[6,5,4- cd ]indoles was achieved via a 1,6-hydride transfer-involved cascade [6 + 1] cyclization in ethanol.