Modular Synthesis of 4-Acylquinolines via Cycloaddition of 1,3-Enynes and Nitrosoarenes

Abstract Herein, we disclose a FeBr2-promoted cycloaddition of readily available 1,3-enynes and nitrosoarenes, providing a promising platform for the synthesis of privileged 4-acylquinoline scaffolds. This simple, one-pot process is characterized by high atom-economy, broad substrate-scope, and excellent functional-group tolerance. A possible reaction mechanism was proposed, involving processes such as [4+2] cycloaddition, ring opening, aromatization, and dehydroaromatization.