Palladium-catalyzed C8-H alkoxycarbonylation of 1-naphthylamines with alkyl chloroformates.

A simple and efficient protocol for palladium-catalyzed C8-H alkoxycarbonylation of 1-naphthylamine derivatives with alkyl chloroformates has been developed, exhibiting broad functional group tolerance, high regioselectivity, and oxidant-free conditions. Furthermore, the reaction features its ease of further functionalization and transformation. For example, the concise synthesis of one BET bromodomain inhibitor was accomplished via benz[cd]indol-2(1H)-one after multistep transformations from the obtained alkoxycarbonylation product. In addition, the control experiments suggest that the reaction might involve a radical process and the C-H bond cleavage might not be involved in the rate-determining step.