Cubic phenylene bridged mesoporous hybrids from allylorganosilane precursors and their applications in Friedel–Crafts acylation reaction

Abstract

The phenylene-bridged hybrid mesoporous silica material with well-defined cubic three-dimensional (Pm3n) symmetry was prepared using a allylorganosilane precursor 1,4-bis(triallylsilyl)benzene and cetyltrimethylammoniumchloride (C 16TMACl) surfactant in acidic medium. Sulfonic acid functionalized derivatives of 3d-cubic phenylene-bridged hybrid mesoporous silica materials were prepared and found effective in Friedel–Crafts acylation reaction. The catalytic results were also compared to the sulfonic acid functionalized derivatives of phenylene-bridged mesoporous silica with 2d-hexagonal (P6 mn) symmetry, sulfonated SBA-1 (Pm3n) mesoporous silica, and sulfonated phenyltrimethoxy silane (PTMS) grafted SBA-1 (Pm3n) mesoporous silica. The degree of sulfonation could be controlled using the different sulfonating agents as well as the time on sulfonation. It was revealed that 3d-cubic mesoporous hybrids could be functionalized with higher concentration of sulfonic acid moieties. Friedel–Crafts acylation reaction was performed over all sulfonated materials. Mesoporous materials derived from allylorganosilane precursors showed an excellent activity in Friedel–Crafts acylation of aromatic ether anisol using acetic anhydride as acylating agent.