A facile regioselective 1,3-dipolar cycloaddition protocol for the synthesis of new class of quinolinyl dispiro heterocycles

The 1,3-dipolar cycloaddition reaction of azomethine ylides generated in situ from isatin and secondary amino acids with quinolinyl dipolarophiles in refluxing methanol afforded new class of quinolinyl dispiro heterocycles with multi hetero core units. The regio and stereochemistry of the product was unambiguously assigned by 1H, 13C, 2D NMR techniques and single crystal X-ray analysis. The structures of the compounds are stabilized through the presence of intermolecular hydrogen bonding and intramolecular non-covalent interactions.