Click synthesis of N¹-(β-D-ribofuranosyl)-C⁴-(coumarin-4″-yl)-1,2,3-triazoles

Abstract

A series of eight N¹-(β-D-ribofuranosyl)-C⁴-(coumarin-4′′-yl)-1,2,3-triazoles have been synthesized by Cu(I)-catalyzed click reaction of 1-azido-1-deoxy-2,3,5-tri-O-benzoyl-β-D-ribofuranose with differently substituted 4-ethynylcoumarins followed by debenzoylation of the resulted N¹-(2′,3′,5′-tri-O-benzoyl-β-D-ribofuranosyl)-C⁴-(coumarin-4″-yl)-1,2,3-triazoles in 71 to 89% overall yields. The structures of all the synthesized compounds were established on the basis of their spectral data analysis that was further confirmed by X-ray data analysis of one of the model benzoylated compounds, i.e. N¹-(2′,3′,5′-tri-O-benzoyl-β-D-ribofuranosyl)-C⁴-(7″-isopropoxycoumarin-4″-yl)-1,2,3-triazole.

Graphical Abstract

Keywords:

• Click chemistry
• 4-ethynylcoumarins
• coumarinyltriazolylglycosides
• 1-azido-1-deoxy-2,3,5-tri-O-benzoyl-β-D-ribofuranose

Acknowledgments

We are grateful to University of Delhi for providing financial support under DU-DST Purse Grant and under scheme to strengthen Research & Development; Vipin K. Maikhuri and Kavita thank CFEES-DRDO and CSIR, New Delhi for the award of Junior Research Fellowships. We are also thankful to CIF-USIC, University of Delhi for providing NMR, other spectral and crystallographic data recording facility.