Rhodium(III)-catalyzed benzo[c]azepine-1,3(2H)-dione synthesis via tandem C–H alkylation and intermolecular amination of N-methoxylbenzamide with 3-bromo-3,3-difluoropropene

Here, a rhodium(III)-catalyzed benzo[c]azepine-1,3(2H)-dione synthesis via tandem C–H alkylation and intramolecular amination of N-methoxylbenzamide with 3-bromo-3,3-difluoropropene as the alkylation agent is reported. The substituted benzamides and protected indoles are all tolerated, yielding the corresponding products in moderate to good yields. Further study revealed those bioactive compounds such as piperic acid and a key precursor of Roflumilast all perform well, highlighting the synthetic utility of this method.