PyBidine/Copper Catalyst: Asymmetric <i>exo′</i>‐Selective [3+2] Cycloaddition using Imino Ester and Electrophilic Indole

Abstract

Electrophilic indoles having two electron-withdrawing groups undergo nucleophilic attack at C2 and electrophilic functionalization at C3. This is the first enantioselective formal [3+2] cycloaddition using electrophilic indoles. The PyBidine/Cu catalyst smoothly promoted highly enantio- and exo'-selective [3+2] cycloaddition using imino esters and 3-nitroindoles. This reaction provides a method for the preparation of diverse and complex chiral pyrroloindoline compounds.