Synthesis of 3-imino-1-benzazepines by the cyanide-incorporating heterocyclization of (2-benzylaminobenzylidene)malonates

A method for the synthesis of 1,2,3,5-tetrahydro-4H-1-benzazepine-4,4-dicarboxylates from 2-[2-(N-benzyl-N-methylamino)benzylidene]malonates and trimethylsilyl cyanide is proposed. The transformation can be considered as the 1,5-hydride shift–cyclization cascade sequence involving the formation of intermediate stable boronate complex.