Copper-catalyzed synthesis of pyrrolo[2,1-a]isoquinolines through condensation/cycloaddition/aromatization cascade

An efficient construction of highly substituted pyrrolo[2,1-a]isoquinoline derivatives has been reached with tetrahydroisoquinolines, aromatic aldehydes and activated olefins through condensation/cycloaddition/aromatization cascade in the presence of copper salts as catalyst. The current approach features the direct use of unactivated aldehydes and high efficiency. Interestingly, the obtained pyrrolo[2,1-a]isoquinolines can be easily modified through reduction, nitration and amidation.