Synthetic Routes to Isomeric Imidazoindoles by Regioselective Ring‐Opening of Activated Aziridines Followed by Copper‐Catalysed C–N Cyclization

Abstract

Ring opening of activated aziridines with i) 2,2‐dibromovinylanilines and ii) 2‐bromoindoles followed by Cu‐catalysed cyclization gives rise to different regioisomers of imidazoindoles. The first route generates one regioisomer, and the second route gives the other. Two new synthetic routes that deliver substituted imidazoindoles in high yields with excellent ee values have been developed. The reactions proceed through ring‐opening of activated aziridines with 2,2‐dibromovinylanilines or 2‐bromoindoles, followed by a Cu‐catalysed domino C–N,C–N‐cyclization, or a C–N cyclization, respectively. The first route gives rise to one regioisomer, and the second route gives the other.