Tandem [3 + 2] Cycloaddition Reaction: Access to Polycyclic Quinolinone-Fused Pyrrolo[2,1-a]isoquinoline Scaffolds.

A domino protocol for the concise preparation of functionalized quinolinone-fused pyrrolo[2,1-a]isoquinoline derivatives from formyl-phenylpropiolamides using tetrahydroisoquinolines was developed without using any catalyst or additive. This green strategy involved cascade intermolecular aldehyde-amine condensation/intramolecular [3 + 2] cycloaddition. Under benign conditions, a diverse range of favorable compounds were smoothly synthesized in good to high yields with diverse functional group compatibility and broad substrate scope.