NBS‐Promoted C−H Amination of Enaminones for the Synthesis of N‐Heterocycle Substituted Enaminones

A NBS‐promoted C−H amination of enaminones has been developed with a variety of N‐heterocycles. This methodology is highly practical as it employs inexpensive and simple NBS promotor under aerobic conditions without the additions of any transition metal catalyst. The transformation proceeds by the initial bromination of enaminones and the subsequent intermolecular substitution with N‐nucleophile to form C−N bond. In this manuscript, we reported N‐bromosuccinimide‐promoted amination of enaminones with N‐heterocycles, generating diverse N‐heterocycle substituted enaminones in moderate to good yields. The bromo enaminones was described as the key active intermediates, which was used to synthesize N‐heterocycle substituted enaminones with moderate to good results for the first time. This method features a wide substrate scope and good functional group tolerance, mild reaction conditions, simple and easy operation and utilizes easily available starting materials.