Periodic Mesoporous Organosilica Functionalized with Sulfonic Acid Groups as Acid Catalyst for Glycerol Acetylation

Abstract

A Periodic Mesoporous Organosilica (PMO) functionalized with sulfonic acid groups has been successfully synthesized via a sequence of post-synthetic modification steps of a trans-ethenylene bridged PMO material. The double bond is functionalized via a bromination and subsequent substitution obtaining a thiol functionality. This is followed by an oxidation towards a sulfonic acid group. After full characterization, the solid acid catalyst is used in the acetylation of glycerol. The catalytic reactivity and reusability of the sulfonic acid modified PMO material is investigated. The catalyst showed a catalytic activity and kinetics that are comparable with the commercially available resin, Amberlyst-15, and furthermore our catalyst can be recycled for several subsequent catalytic runs and retains its catalytic activity.

Novel magnetic propylsulfonic acid-anchored isocyanurate-based periodic mesoporous organosilica (Iron oxide@PMO-ICS-PrSO3H) as a highly efficient and reusable nanoreactor for the sustainable synthesis of imidazopyrimidine derivatives

“…Also, these type of materials have been used as suitable supports in a diversity of heterogeneous catalysts for different organic reactions [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] . Indeed, the mesopore channels and high surface area of PMOs make them as an appropriate nanoreactor for releasing of the reactants into mesoporous channels and increases the reaction rate [30][31][32][33][34][35][36][37][38][39][40][41] . In addition to the above mentioned properties, another special features of PMOs are uniform distribution of active organic groups within their framework to tune their polarity compared to nanoordered silica materials and reusability 13 .…”

Functionalized Periodic Mesoporous Organosilicas: Tunable Hydrophobic Solid Acids for Biomass Conversion

“…Arene sulfonic acid groups were introduced into ethylene framework PMOs via Diels–Alder reaction of the ethylene group with benzocyclobutene to form a phenylene species [111], or alkylation with phenyl using homogeneous AlCl 3 [112]; subsequent sulfonation with H 2 SO 4 successfully produced sulfonic acid groups. Alternatively, ethylene bridges in PMO materials can undergo epoxidation followed by sulfonation using bisulphite/HCl to form sulfonic acid [113] (Scheme 8), or, if subjected to bromination, can initiate a Grignard reaction with 3-chloro-1-propanethiol, followed by oxidation to form tethered propyl sulfonic acid groups [114]. Another approach to introduce sulfonic acid groups is via grafting of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane or 3-glycidoxypropyltrimethoxysilane, whose epoxy groups react with sodium sulfite under mildly oxidizing conditions to form sulfonic acids [115].…”

“…Sulfonic-acid-derivatized PMOs attracted significant interest as solid Brønsted acid catalysts for a variety of organic transformations including fructose dehydration to 5-HMF [121], alcohol acetylation [114,122], condensation reactions of indole with benzaldehyde [123], organic acid esterification [59,78,102,113,124], triglyceride transesterification reactions [54,103], and the protection/deprotection of alcohols with tetrahydrofuran [39].…”

Glycerol Acetylation with Propionic Acid Using Iron and Cobalt Oxides in Al-MCM-41 Catalysts

“…Several studies have been published related to glycerol acetylation with acetic acid using heterogeneous catalysts that enrich both Brønsted and Lewis acidic sites. Acid zeolites, acid clays, modified molecular sieves, heteropoly acids, metal oxides, ion exchange resins, among others, with modifications in their chemical structures, are being responsible for increasing the number of acidic sites that were employed in the production of acetyl glycerides [17][18][19][20][21][22][23][24][25][26]. Heterogeneous acidic catalysts showed gains in glycerol functionalization towards derived products.…”