Au(I)–N-heterocyclic carbene complex-catalyzed synthesis of 1-substituted benzo[b][1,4]diazepines from N-substituted o-phenylenediamines and terminal alkynes

•An Au(I)-NHC-catalyzed process for benzo[b][1,4]diazepines was developed.•1-Substituted benzo[b][1,4]diazepines were efficiently prepared.•Fused tricyclic benzo[b][1,4]diazepines were accessed for the first time.

1-Substituted benzo[b][1,4]diazepines which are difficult to synthesize by traditional methods have been prepared by an Au(I)–N-heterocyclic carbene complex-catalyzed tandem hydroamination/cyclization process. This protocol features the one-pot formation of a seven-membered N-heterocycle via atom-economic hydroamination/cyclization reactions of readily available N-substituted o-phenylenediamines and terminal alkynes. Based on this strategy, fused tricyclic benzo[b][1,4]diazepines have been accessed for the first time.

Graphical abstract1-Substituted and fused polycyclic benzo[b][1,4]diazepines which are difficult to be accessed previously have been synthesized by Au(I)–NHC complex-catalyzed tandem hydroamination/cyclization protocol.Figure optionsDownload full-size imageDownload as PowerPoint slide