title: Copper(I)-Y Zeolite-Catalyzed Regio- and Stereoselective [2 + 2 + 2] Cyclotrimerization Cascade: An Atom- and Step-Economical Synthesis of Pyrimido[1,6-a]quinoline.
abstract: An elegant copper(I)-Y zeolite-catalyzed tandem process, involving ketenimine-based termolecular [2 + 2 + 2]/[NC + CC + NC] cycloaddition, using sulfonyl azide, alkyne, and quinoline, to prepare pyrimido[1,6-a]quinolines is reported. In this straightforward, highly atom- and step-economical protocol, copper(I) promotes for azide-alkyne [3 + 2] cycloaddition which is followed by ring-rearrangement/ketenimine formation/regio- and stereoselective [2 + 2 + 2] termolecular cycloaddition and dehydrogenation cascade to yield selectively the E-isomer of pyrimido[1,6-a]quinoline.
authors.affiliation: School of Chemistry and ‡Centre for Green Chemistry Processes, School of Chemistry, Madurai Kamaraj University , Madurai 625 021, India.
authors.forename: Devenderan
authors.initials: D
authors.lastname: Ramanathan
authors.affiliation: School of Chemistry and ‡Centre for Green Chemistry Processes, School of Chemistry, Madurai Kamaraj University , Madurai 625 021, India.
authors.forename: Kasi
authors.initials: K
authors.lastname: Pitchumani