A Synthetic Route to Chiral 1,4-Disubstituted Tetrahydro-β-Carbolines via Domino Ring-Opening Cyclization of Activated Aziridines with 2-Vinylindoles.

A simple and efficient strategy for the synthesis of various 1,4-disubstituted tetrahydro-β-carbolines with excellent stereoselectivity (de, ee up to >99%) via domino ring opening cyclization (DROC) of activated aziridines with 2-vinylindoles is described. The reaction proceeds through LiClO4 -catalyzed Friedel-Crafts-type alkylation of 2-vinylindoles with activated aziridines followed by an intramolecular aza-Michael reaction in a domino fashion.