Development of Trifluoromethanesulfonic Acid-Immobilized Nitrogen-Doped Carbon-Incarcerated Niobia Nanoparticle Catalysts for Friedel–Crafts Acylation

Abstract

Heterogeneous trifluoromethanesulfonic acid-immobilized nitrogen-doped carbon-incarcerated niobia nanoparticle catalysts (NCI-Nb-TfOH) that show excellent catalytic performance with low niobium loading (1 mol %) in Friedel–Crafts acylation have been developed. These catalysts exhibit higher activity and higher tolerance to catalytic poisons compared with the previously reported TfOH-treated NCI-Ti catalysts, leading to a broader substrate scope. The catalysts were characterized via spectroscopic and microscopic studies.

Regioselective Friedel–Crafts Acylation Reaction Using Single Crystalline and Ultrathin Nanosheet Assembly of Scrutinyite-SnO2

“…All the peaks can be assigned to the medium temperature region (300–450 °C), which indicates the presence of medium strength acidic sites in the SnO 2 nanosheets. 72 Moreover, the nature and stability of the acidic sites in the synthesized SnO 2 nanosheets are evaluated by performing Py-FTIR analysis at different temperatures, and the results are presented in Figure 5 . The Py-FTIR spectra exhibit bands at 1610, 1575, and 1450 cm –1 corresponding to the vibrational modes of pyridine coordinated at Lewis acidic sites (L).…”

“…In general, the strength of acidic sites can be divided into weak (200–300 °C), medium (300–450 °C), and high (>450 °C) regions. , The measured NH 3 -TPD profile is deconvoluted into three peaks having maximal temperatures at ∼320, 361, and 446 °C corresponding to 23, 45, and 32% of the total desorbed amount of NH 3 . All the peaks can be assigned to the medium temperature region (300–450 °C), which indicates the presence of medium strength acidic sites in the SnO 2 nanosheets . Moreover, the nature and stability of the acidic sites in the synthesized SnO 2 nanosheets are evaluated by performing Py-FTIR analysis at different temperatures, and the results are presented in Figure .…”

Targeted development of sustainable green catalysts for regioselective acylation of aromatic ethers with carboxylic acidsviachlorosulfonic acid coated on poly(guanidine–triazine–sulfonamide) grafted quartz–γ-Fe2O3

“…3 Typically, FC acylation is promoted by protic or Lewis acids that require a specific amount of catalyst regarding product inhibition. 4 Recently, several efforts have been made to enhance the FC reaction by developing high-performance catalysts. 3,5 In addition, catalysts (e.g., Nafion, zeolites, clays, graphene, metal oxides, and acids) and novel media (e.g., heterogeneous supports and ionic liquids) have been used for this purpose.…”

“…3 Typically, FC acylation is promoted by protic or Lewis acids that require a specific amount of catalyst regarding product inhibition. 4 Recently, several efforts have been made to enhance the FC reaction by developing high-performance catalysts. 3,5 In addition, catalysts ( e.g.…”

Mechanism of Friedel–Crafts Acylation Using Metal Triflate in Deep Eutectic Solvents: An Experimental and Computational Study

“…Friedel–Crafts acylation reaction is one of the important reactions of synthetic aromatic ketones. , The common acylation reaction employs acyl chlorides, acid anhydrides, or carboxylic acids as acylating reagents in the presence of traditional catalysts including Lewis acids − (anhydrous ZnCl 2 , A1Cl 3 , FeCl 3 ) or Brønsted acids − (concentrated sulfuric acid, hydrochloric acid), nanoparticles, − ionic liquids, − metal triflates, , mesoporous zeolite, nitrogen-doped carbon, , metal oxides, heteropoly acids, , and solid superacids . Besides, several effective methods were applied to the Friedel–Crafts acylation reaction, including flow chemistry, ultrasound activation, and microwave irradiation …”