N-Heterocyclic Carbene-Catalyzed Enantioselective -Amination of -Bromoenals Enabled by a Proton-Shuttling Strategy

An unprecedented enantioselective NHC-catalyzed -amination of -bromoenals with o-benzodiamines was developed by utilizing a proton-shuttling strategy. This formal [4+3] annulation protocol yielded the corresponding 1,5-benzodiazepines in high yields with excellent enantioselectivities. The obtained optically active 1,5-benzodiazepines as building blocks and pharmacophores should be useful in the synthesis of other valuable molecules or in drug discovery.