ChemInform Abstract: New Methodology for the Preparation of Pyrrole and Indole Derivatives via Iminophosphoranes: Synthesis of Pyrrolo(1,2‐a)quinoxalines, Indolo(3,2‐c)quinolines and Indolo(1,2‐c)quinazolines.

Abstract

Abstract The aza-Wittig reaction of iminophosphorane N-[o-(triphenylphosphoranylidene)amino]-phenyl pyrrole 4 with heterocumulenes leads to functionalized pyrrolo[l,2-a]quinoxalines. Iminophosphorane 19 , derived from 2-(o-amino)phenyl indole, reacts under mild conditions with isocyanates to form 21 which are converted into 5-amino-11H-indolo[3,2-c]quinolines 22 . Iminophosphorane 19 also reacts with carbon dioxide and carbon disulfide to give indolo[3,2-c]quinolines 23 . Iminophosphorane 28 . derived from 2-fo-azido)-phenyl-3-phenyl indole, reacts with isocyanates, carbon dioxide and carbon disulfide to form indolo[l,2-c]-quinazolines 29 and 30 respectively.