40811-14-1Relevant articles and documents
A Copper Metal–Organic Hydrogel as a Catalyst for SO2 and CO2 Fixation under Ambient Conditions
Karan, Chandane Kumar,Bhattacharjee, Manish
, p. 3605 - 3611 (2019/08/20)
A copper metal–organic hydrogel (MOG) has been synthesized using an amino acid-based ligand, Na2HL {H3L = 2-{(3,5-di-tert-butyl-2-hydroxybenzyl)amino succinic acid} as a gelator. The metallohydrogel exhibits pH-responsive nature as well as chemical responsiveness. Besides, it shows rapid thixotropic behavior when external mechanical forces are applied. The metal–organic hydrogel can be used as a heterogeneous catalyst for the reaction of SO2 and CO2 with epoxides to produce cyclic 1,3,2-dioxathiolane-2-oxides and carbonates, respectively. The conversions were found to be dependent on the size and type of the side chain of the epoxides.
A method for preparing [...] (by machine translation)
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Paragraph 0023-0026; 0031; 0033-0034; 0039; 0041-0042, (2019/05/29)
The invention relates to a method for preparing [...], comprising the following steps: S1. The nucleophilic substitution reaction: to propylene glycol and thionyl chloride as the starting material, chloroform as solvent, the nucleophilic substitution reaction, by the sulfurous acid propylene chloroform solution; S2. Oxidation reaction: high iodic acid as the oxidizing agent, the ruthenium trichloride hydrate catalyst, to S1 to obtain solution in the oxidation process is performed on the sulfurous acid propylene shall [...]; S3. The refined purification: sulfuric acid propylene crude soluble in chloroform, under the protection of nitrogen, heating to reflux is fully dissolved, then lower the temperature crystallization, filtering, filters the cake to pass through reduced-pressure drying, to obtain. The mild reaction conditions of the present invention, the synthetic process is simple, easy to operate, high safety, preparation cycle is short, the raw materials used are simple and easy to obtain, the cost is low, few by-products, the preparation of the product has high purity, low water content, low acid value of the product, the product yield is high, and is suitable for industrial production. (by machine translation)
Synthesis of cyclic sulfites from epoxides and sulfur dioxide with silica-immobilized homogeneous catalysts
Takenaka, Yasumasa,Kiyosu, Takahiro,Mori, Goro,Choi, Jun-Chul,Fukaya, Norihisa,Sakakura, Toshiyasu,Yasuda, Hiroyuki
experimental part, p. 194 - 199 (2012/06/30)
Quaternary ammonium- and amino-functionalized silica catalysts have been prepared for the selective synthesis of cyclic sulfites from epoxides and sulfur dioxide, demonstrating the effects of immobilizing the homogeneous catalysts on silica. The cycloaddition of sulfur dioxide to various epoxides was conducted under solvent-free conditions at 100 °C. The quaternary ammonium- and amino-functionalized silica catalysts produced cyclic sulfites in high yields (79-96 %) that are comparable to those produced by the homogeneous catalysts. The functionalized silica catalysts could be separated from the product solution by filtration, thereby avoiding the catalytic decomposition of the cyclic sulfite products upon distillation of the product solution. Heterogenization of a homogeneous catalyst by immobilization can, therefore, improve the efficiency of the purification of crude reaction products. Despite a decrease in catalytic activity after each recycling step, the heterogeneous pyridine-functionalized silica catalyst provided high yields after as many as five recycling processes. Immobilized for crimes of pyrolysis: Quaternary ammonium- and amino-functionalized silica catalysts promote the cycloaddition of sulfur dioxide to epoxides to produce cyclic sulfites in high yields (79-96 %) that are comparable to those with the homogeneous catalysts. Separation of the functionalized silica catalyst from the product solution by filtration avoids pyrolysis of the cyclic sulfites during purification by distillation. Copyright
Potent ketoamide inhibitors of HCV NS3 protease derived from quaternized P1 groups
Venkatraman, Srikanth,Velazquez, Francisco,Wu, Wanli,Blackman, Melissa,Madison, Vincent,Njoroge, F. George
scheme or table, p. 2151 - 2155 (2010/06/19)
Blood borne hepatitis C infections are the primary cause for liver cirrhosis and hepatocellular carcinoma. HCV NS3 protease, a pivotal enzyme in the replication cycle of HCV virus has been the primary target for development of new drug candidates. Boceprevir and telaprevir are two novel ketoamide derived inhibitors that are currently undergoing phase-III clinical trials. These inhibitors include ketoamide functionality as serine trap and have an acidic alpha-ketoamide center that undergoes epimerization under physiological conditions. Our initial attempts to arrest this epimerization by introducing quaternary amino acids at P1 had resulted in significantly diminished activity. In this manuscript we describe alpha quaternized P1 group that result in potent inhibitors in the enzyme assay and demonstrate cellular activity comparable to boceprevir.
Synthesis of hydroxy sulfonate surfactants
Rist, ystein,Carlsen, Per H. J.
, p. 1169 - 1178 (2007/10/03)
The selective synthesis of sulfonate surfactants with side chains containing ether- and hydroxy groups was carried out using cyclic sulfates as epoxide analogues. The main chain was elaborated from 1,2-dodecane sulfate by the addition of various hydroxy/alkoxysulfonates. Ethyleneoxy- and 1,2-propyleneoxy- groups were introduced using ethylene sulfate and 1,2-propylene sulfate, respectively.
Total synthesis of (-)-spirotryprostatin B: Synthesis and related studies
Marti, Christiane,Carreira, Erick M.
, p. 11505 - 11515 (2007/10/03)
The total synthesis of spirotryprostatin B, a cytostatic spiro[pyrrolidine-3,3′-oxindole] alkaloid, is described. The key step of the synthetic approach consists of the application of the Mgl 2-mediated ring-expansion reaction of a spiro[cyclopropane-1, 3′-oxindole] with an aldimine, leading to rapid assembly of the spirotryprostatin core. The route documents the installation of the prenyl side chain by Julia-Kocienski olefination of a key aldehyde precursor, a transformation that ultimately allows for facile synthesis of analogues and facilitates structure-activity relationships studies.
REACTION OF HYDROXY AND CARBONYL COMPOUNDS WITH SULFUR TETRAFLUORIDE IX. REACTIONS OF GLYCOLS WITH SULFUR TETRAFLUORIDE
Hassanein, Salah Mohamed,Burmakov, A. I.,Bloshchitsa, F. A.,Yagupol'skii, L. M.
, p. 1473 - 1477 (2007/10/02)
Selective substitution of one of the hydroxyl groups by a fluorine atom occurs in the reactions of 1,2-, 1,3-, and 1,4-glycols with sulfur tetrafluoride under mild conditions.The regioselectivity of substitution in the case of unsymmetrical glycols depends on the electronic nature of the groups present in the molecules of the initial compounds.
