Trifluoroacetic acid catalyzed dibenzodiazocine synthesis: optimization and mechanism study

Dibenzo[b,f][1,5]diazocines, a class of potential building blocks for novel electrochemical actuators, were synthesized via a novel, efficient acid-catalyzed reaction of 2-acylbenzoisocyanate at room temperature. Real-time NMR analysis and the captured intermediate showed the mechanism was an unprecedented cyclization of the isocyanate with the neighboring acyl group, followed by the dimerization.