Unexpected synthesis of indolo[1,2-c]quinazolines by a sequential Ugi 4CC–Staudinger–aza-Wittig–nucleophilic addition reaction?

Organic & Biomolecular Chemistry Pub Date: 2010-11-17 DOI: 10.1039/C0OB00855A

Abstract

A new sequential Ugi–Staudinger–aza-Wittig–nucleophilic addition reaction was developed to construct indolo[1,2-c]quinazoline derivatives, starting from the easily accessible 2-azidobenzaldehyde, carboxylic acid, 2-acylaniline and isocyanide. It is noteworthy that this is the first report of the cyclization of the Ugi adduct to give a dihydroindole ring system with two quaternary carbon centers, via the nucleophilic addition reaction of the methine group to the carbonyl group.

Graphical abstract: Unexpected synthesis of indolo[1,2-c]quinazolines by a sequential Ugi 4CC–Staudinger–aza-Wittig–nucleophilic addition reaction
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