EtOH-mediated cascade C(sp3)–H alkylation via aromatization-driven [1,6]-hydride transfer: green and divergent synthesis of spirocyclic azepino[4,3,2-cd]indoles

Unprecedented EtOH-mediated cascade C(sp 3 )–H alkylation reactions of 4-dialkylamino-indole-3-carbaldehydes have been realized for the green and divergent synthesis of spirocyclic azepino[4,3,2- cd ]indole derivatives.