A Photoredox‐Induced Stereoselective Dearomative Radical (4+2)‐Cyclization/1,4‐Addition Cascade for the Synthesis of Highly Functionalized Hexahydro‐1<i>H</i>‐carbazoles

Abstract

A stereoselective synthesis of functionalized hexahydrocarbazoles was developed based on an unprecedented photoredox-induced dearomative radical (4+2)-cyclization/1,4-addition cascade between 3-(2-iodoethyl)indoles and acceptor-substituted alkenes. The title reaction simultaneously generates three C-C bonds and one C-H bond, along with three contiguous stereogenic centers. The hexahydro-1H-carbazole products are highly valuable intermediates for the synthesis of novel antibiotics, as well as unnatural ring homologues of polycyclic indoline alkaloids.