Xi:Irritant;
6362-80-7Relevant articles and documents
One-pot synthesis of a novel catalyst with strong acid sites based on carbon/silica composite
Wu, Linxi,Wu, Ye,Liang, Xuezheng
, p. 378 - 381 (2013)
A novel catalyst with strong acid sites based on carbon/silica composite has been synthesized through one-pot hydrothermal carbonization of hydroxyethylsulfonic acid, glucose and tetraethyl orthosilicate (TEOS). The novel solid acid showed an acidity of 2.1 mmol/g, much higher than that of traditional solid acids such as Nafion and Amberlyst-15 (0.8 mmol/g). The catalytic activity of the solid acid was investigated in the acetalization and dimerization of α-methylstyrene. The results showed that the novel solid acid was very efficient for both hydrophilic and hydrophobic acid-catalyzed reactions. Because of the high acidity and catalytic activity the novel solid acid based on carbon/silica composite is a promising catalyst for the processes in green chemistry.
Highly selective photo-catalytic dimerization of α-methylstyrene by a novel palladium complex with photosensitizing ruthenium(II) polypyridyl moiety
Inagaki, Akiko,Edure, Shinichi,Yatsuda, Shinichi,Akita, Munetaka
, p. 5468 - 5470 (2005)
A novel dinuclear complex containing the photo-sensitizing Ru unit and a Pd center is effective toward selective catalytic dimerization of α-methylstyrene leading to 2,4-diphenyl-4-methyl-1-pentene under visible-light irradiated conditions. The Royal Society of Chemistry 2005.
Selective dimerization of a-methylstyrene by tunable bis(catecholato)germane Lewis acid catalysts
Baines, Kim M.,Boyle, Paul D.,Cosby, Taylor P. L.,Henry, Andrew T.
supporting information, p. 15906 - 15913 (2021/12/02)
The synthesis of a variety of bis(catecholato)germanes is reported. The Lewis acidity of the bis(catecholato)germanes was assessed using the experimental Gutmann-Beckett method and computational FIA and GEI methods. The oligomerization of alkenes using bis(catecholato)germanes demonstrates the use of these complexes in catalysis. The use of donor additives in the dimerization of a-methylstyrene resulted in selectivity control comparable to transition metal catalyst systems. This journal is
Photoinduced [3+2] Annulation of Alkene with o-Iodoanilines: An Expedient Approach to Indolines
Zhao, Xinxin,Guo, Lin,Yang, Chao,Xia, Wujiong
supporting information, p. 1341 - 1348 (2020/11/19)
A highly regioselective [3+2] cyclization of alkenes with 2-iodoanilines under the irradiation of UV light is described. This general, metal-free strategy facilitates the direct preparation of 2-mono-/disubstituted indolines as well as spiroindolines through alkene carboamination in one step. Mechanistic studies suggested that the photochemical protocol proceeded via a radical pathway.
Aerobic Oxidation of Secondary Alcohols with Nitric Acid and Iron(III) Chloride as Catalysts in Fluorinated Alcohol
Mo?ina, ?tefan,Iskra, Jernej
, p. 14579 - 14586 (2019/11/14)
Fluorinated alcohols as solvents strongly influence and direct chemical reaction through donation of strong hydrogen bonds while being weak acceptors. We used 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the activating solvent for a nitric acid and FeCl3-catalyzed aerobic oxidation of secondary alcohols to ketones. Reaction proceeded selectively with excellent yields with no reaction on the primary alcohol group. Oxidation of benzyl alcohols proceeds selectively to aldehydes with only HNO3 as the catalyst, while reaction on tertiary alcohols proceeds through dehydration and dimerization. A mechanistic study showed in situ formation of NOCl that converts alcohol into alkyl nitrite, which in the presence of Fe3+ ions and fluorinated alcohol decomposes into ketone. The study indicates that iron(III) acts also as the single-electron transfer catalyst in regeneration of NOCl reactive species.
Variations on the Theme of JohnPhos Gold(I) Catalysts: Arsine and Carbene Complexes with Similar Architectures
Carreras, Javier,Pereira, Ana,Zanini, Margherita,Echavarren, Antonio M.
supporting information, p. 3588 - 3597 (2018/10/31)
Arsine and carbene gold(I) complexes with architectures closely related to those of 2-(di-tert-butylphosphino)biphenyl gold(I) complexes have been prepared and structurally characterized. As predicted, 2-(di-tert-butylarsine)biphenyl gold(I) complexes are more electrophilic catalysts in comparison to their phosphine analogues, whereas those based on 4-arylindazole behave similarly to NHC-gold(I) catalysts.
METHOD FOR MANUFACTURING α-METHYLSTYRENATED PHENOL
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Paragraph 0035; 0036; 0067-0070; 0084, (2017/10/14)
According to an embodiment of the present invention, the present invention provides a method for manufacturing α-methyl styrenated phenol, which comprises the following steps: (a) making phenol react with α-methyl styrene (AMS) under the presence of a first acidic catalyst to obtain a first product; and (b) additionally making 1-5 equivalents of α-methyl styrene for 1 equivalent of phenol react with the first product under the presence of a second acidic catalyst to obtain a second product. The manufactured α-methyl styrenated phenol does not generate environmental damage and is economical.(a) Making phenol react with α-methyl styrene (AMS) under the presence of a first acidic catalyst(AA) Obtaining 30-50 wt% of TMPI, 1-10 wt% DMP, 5-20 wt% of cumyl phenol, 1-10 wt% of AMS trimer, and the remaining phenol(b) Additionally making the α-methyl styrene react with a first product under the presence of a second acidic catalyst(BB) Obtaining 5-50 wt% of TMPI + DMP, 2-20 wt% of cumyl phenol, 1-10 wt% of dicumene, 20-60 wt% of dicumyl phenol, and 0.1-5 wt% of AMS trimerCOPYRIGHT KIPO 2017
Surface reactivity of non-hydrolytic silicophosphate xerogels: A simple method to create Br?nsted or Lewis acid sites on porous supports
Styskalik, Ales,Skoda, David,Moravec, Zdenek,Barnes, Craig E.,Pinkas, Jiri
, p. 3705 - 3715 (2016/05/09)
Non-hydrolytic sol-gel reactions of silicon acetates with trimethylsilyl (TMS) esters of phosphoric and phosphonic acids produce cross-linked matrices containing homogeneous dispersions of silicate and phosphoryl groups connected together by networks of Si-O-P(=O) linkages. The condensation degrees reach 80 to 90%. Residual organic groups (10 to 20%) were reacted with a variety of compounds (H2O, Me3SiOSiMe3, POCl3, SiCl4, AlMe3, Al(NMe2)3, and AlCl3) in order to enrich the surface of these porous matrices with Br?nsted (≡P-OH) and Lewis (tetracoordinated Al) acid functional groups. The differences in the reactivity of ≡Si-OAc and ≡P-OSiMe3 groups were utilized for the selective modification at the silicon and phosphorus atoms. The reaction procedures were optimized and significantly porous silicophosphate materials with a high content of either hydroxyl groups or four-coordinated aluminium species were obtained. The activity and selectivity of prepared samples as catalysts for the dimerization of α-methylstyrene were tested. Excellent activities and moderate to very high selectivities were achieved suggesting the potential use of silicophosphate xerogels in heterogeneous catalysis.
Calcium(II) catalyzed regioselective dehydrative cross-coupling reactions: Practical synthesis of internal alkenes and benzopyrans
Yaragorla, Srinivasarao,Pareek, Abhishek,Dada, Ravikrishna,Almansour, Abdulrahman I.,Arumugam, Natarajan
supporting information, p. 5841 - 5845 (2016/12/14)
A simple and operationally easy protocol for the regioselective synthesis of internal alkenes through a dehydrative cross-coupling and direct coupling procedure has been described using the environmentally benign Ca(II) catalyst. Several alkenes and alcohols underwent the coupling reaction under solvent-free conditions in a short time to produce the desired alkenes. This method is further extended to show the application in the synthesis of novel benzopyran molecules through a cascade strategy.
An Eco-friendly Soft Template Synthesis of Mesostructured Silica-Carbon Nanocomposites for Acid Catalysis
Zhong, Ruyi,Peng, Li,De Clippel, Filip,Gommes, Cedric,Goderis, Bart,Ke, Xiaoxing,Van Tendeloo, Gustaaf,Jacobs, Pierre A.,Sels, Bert F.
, p. 3047 - 3058 (2015/09/22)
The synthesis of ordered mesoporous silica-carbon composites was explored by employing TEOS and sucrose as the silica and carbon precursor respectively, and the triblock copolymer F127 as a structure-directing agent via an evaporation-induced self-assembly (EISA) process. It is demonstrated that the synthesis procedures allow for control of the textural properties and final composition of these silica-carbon nanocomposites via adjustment of the effective SiO2/C weight ratio. Characterization by SAXS, N2 physisorption, HRTEM, TGA, and 13C and 29Si solid-state MAS NMR show a 2D hexagonal mesostructure with uniform large pore size ranging from 5.2 to 7.6 nm, comprising of separate carbon phases in a continuous silica phase. Ordered mesoporous silica and non-ordered porous carbon can be obtained by combustion of the pyrolyzed nanocomposites in air or etching with HF solution, respectively. Sulfonic acid groups can be readily introduced to such kind of silica-carbon nanocomposites by a standard sulfonation procedure with concentrated sulfuric acid. Excellent acid-catalytic activities and selectivities for the dimerization of styrene to produce 1,3-diphenyl-1-butene and dimerization of α-methylstyrene to unsaturated dimers were demonstrated with the sulfonated materials. Tintin and the sulfurous nanocatalysts: Sulfonic acid groups can be readily introduced to mesostructured silica-carbon nanocatalysts to reveal excellent acid-catalytic activities and selectivities for the dimerization of styrene to produce 1,3-diphenyl-1-butene and the dimerization of α-methylstyrene.
