CuI/Cu(OSO₂CF₃)₂ catalysed convenient approach to dichromenopyridines and triazole-thiazole appended chromone derivatives

Abstract

A variety of new pentacyclic dichromenopyridines have been synthesized from 2-amino chromone and O-propargyloxy salicilaldehydes through intramolecular Povarov reaction using CuI/Cu(OSO₂CF₃)₂ as a Lewis acid catalyst. The dichromenopyridines synthesis involve two sequential steps, insitu N-heteryl aldimine formation and an intramolecular Aza Diels-Alder[4 + 2] cycloaddition. Furthermore the key intermediate, terminal alkyne tethered Schiff bases subjected to Cu(I) mediated click [3 + 2] cycloaddition with thiazole appended azide to afford imine linked chromone-1,2,3-triazole -thiazole tri heterocyclic molecular hybrids.

Graphical Abstract

Keywords:

• 2-Amino chromone
• chromone-1,2,3-triazole–thiazole
• dichromenopyridine

Acknowledgement

We thank the HOD's Osmania University, Telangana University, and JNTU Hyderabad for the opportunity to pursue his Ph.D. Our sincere thanks to Dr. M. S. N. Reddy for providing infrastructural facilities to carry out the research work and we are also indebted to S. Eswaraiah and S. T. Rajan for their continuous guidance and support.

Additional information

Funding

This work was financially supported by MSN Laboratories Private Limited, Hyderabad, India.