TMSCl-Catalyzed Aza-Diels-Alder Reaction: A Simple and Efficient Synthesis of Pyrano- and Furanoquinolines

An efficient TMSCl-catalyzed synthesis of pyrano- and furanoquinolines and phenanthridinone derivative has been developed. In the presence of TMSCl (20 mol%), various aliphatic, ­aromatic and heteroaromatic aldehydes reacted with different anilines in the presence of either 2,3-dihydrofuran, 3,4-dihydro-2H-pyran or cyclohexenone to afford the aza-Diels-Alder adducts in excellent yield at room temperature. The ambient conditions, fast reaction rates, and excellent product yields are important characteristics of this reaction.