A modular approach for the synthesis of dibenzoazepine derivatives

A straightforward reaction sequence consisting of a Sonogashira coupling of protected propargylic amines, a cobalt-catalysed neutral Diels-Alder reaction, DDQ oxidation of the dihydroaromatic intermediate, a sodium borohydride reduction and an acid induced Friedel-Crafts-type cyclisation approach incorporating four simple starting materials leads to polyfunctionalised polycyclic products. Based on the electronic, steric and structural preconditions either seven-membered dibenzoazepine derivatives or alternatively six- or eight-membered isoindoline derivatives are formed.