Efficient Synthesis of 9H‐Pyrrolo[1,2‐α]Indoles via Michael Addition–Condensation of 3‐Substituted Indoles with α,β‐Unsaturated Ketimines

By employing copper dibromide as a catalyst, Michael addition-condensation of 3-substituted indoles with ,-unsaturated ketimines was realized. The reactions afforded a large variety of 9H-pyrrolo[1,2-]indoles with good yields (up to 99 %). In addition, a plausible reaction mechanism was proposed.