One-Pot Cascade Leading to Direct α‑Imidation of Ketones by a Combination of N‑Bromosuccinimide and 1,8-Diazabicyclo[5.4.1]undec-7-ene

A one-pot cascade transformation of ketones into α-imidoketones has been developed, in which N-bromosuccinimide (NBS) provides both electrophilic bromine and nucleophilic nitrogen sources, and diazabicyclo[5.4.1]undec-7-ene (DBU) functions as a base and a nucleophilic promoter for the activation of NBS. α-Bromination is supposed as the key step in the process, which takes place between more electrophilic bromide active species and enolates.