Abstract
We describe the use of biocompatible gum acacia (GA)-assembled Ag-TiO2 and Ag-SiO2 nanostructures as effective heterogeneous catalysts for the synthesis of 5-substituted
1H-tetrazoles through the traditional [3+2] cycloaddition of aryl nitriles with sodium
azides. Characterization of the prepared catalysts employing TEM, XPS, FE-SEM, FT-IR,
XRD, and TGA-DTG reveals silver nanoparticles encapsulated in the GA matrix amidst
modified nano titania or silica. A variety of structurally divergent aryl nitriles
were converted into the corresponding tetrazoles in a short reaction time. Other advantages
include low catalytic load, easy handling of catalyst, limited use of toxic reagents,
and desirable conversion yields, making this protocol a viable and practical alternative
for this cyclization. The catalysts can be easily recovered and reused over multiple
cycles without significant loss of catalytic activity.
Key words
nanohybrids - biocomposites - 5-substituted 1
H-tetrazoles - gum acacia - silver nanoparticles
