Novel syntheses of tetrahydrobenzodiazepines and dihydropyrazines via isocyanide-based multicomponent reactions of diamines.

In this work, two novel isocyanide-based multicomponent reactions of 1,2-diamine compounds with diketene have been developed as efficient strategies for the synthesis of 2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepine-2-carboxamides with regiochemical control and 1,6-dihydropyrazine-2,3-dicarbonitriles in good to excellent yields at ambient temperature.