CuI anchored onto mesoporous SBA-16 functionalized by aminated 3-glycidyloxypropyltrimethoxysilane with thiosemicarbazide (SBA-16/GPTMS-TSC-CuI): a heterogeneous mesostructured catalyst for S-arylation reaction under solvent-free conditions

Abstract

Herein, we report the novel synthesis of Cu^I anchored onto a cage-like mesoporous material (SBA-16), which was successfully functionalized by aminated 3-glycidyloxypropyltrimethoxysilane with thiosemicarbazide (SBA-16/GPTMS-TSC-Cu^I) into an efficient and highly recyclable heterogeneous catalyst. The as-synthesized mesostructured catalyst (SBA-16/GPTMS-TSC-Cu^I) was comprehensively characterized by different techniques, namely, FT-IR, FIR, SAXRD, XRD, XPS, BET, TEM, FE-SEM, EDX, EDX mapping, TGA, ICP-OES, and CHNS analyses. SBA-16 with a unique “super-cage” structure efficiently controlled the formation of dispersed organic and metal species in the mesoporous channels. These confined nanoparticles with a narrow particle size distribution (3–7 nm) exhibited excellent catalytic activity in the S-arylation reaction without necessitating the use of toxic solvents and/or expensive metal catalysts. Interestingly, the mesoporous catalyst was extremely stable under the reaction conditions and could be easily separated by a simple filtration process and reused for at least seven recycle runs (without any appreciable loss in catalytic activity). Due to the inimitable structure of the abovementioned mesostructured catalyst, the C–S coupling products of aryl halides with S₈/thiourea under solvent-free conditions were obtained in good to excellent yields in remarkably reduced reaction times in comparison to those reported in earlier studies.