Pyridyl Glycosyl Triazole/CuI-Mediated Domino/Tandem Synthesis of Quinazolinones.

Abstract

The glycosyl 1,2,3-triazoles are expediently accessible from readily available sugar-derived glycosyl azide by utilizing modular CuAAC "Click Chemistry", and the resulting glycohybrid skeleton possesses efficient metal-coordinating centers that support a wide range of metal-mediated efficient catalysis in various imperative organic transformations. Here, we designed and developed pyridyl glycosyl triazoles by employing the CuAAC reaction of d-glucose-derived glycosyl azides and alkynyl pyridines. These pyridyl glycosyl triazoles with Cu(I) salt were explored as an efficient catalyst to successfully assemble 2-amino-3-substituted and 3-substituted quinazolinones by the domino/tandem cross-coupling reaction of various N-substituted o-halobenzamides with cyanamide and formamide, respectively. The devised protocol has some notable features, including biocompatibility, low cost, easily accessible starting materials for the glycosyl ligands, high yield, broad spectrum, low catalytic loading, and mild reaction conditions.