synthesis of cyclicsulfinates and sulfinamides based on intramolecular homolyticsubstitution (SHi) at the sulfuratom by aryl or alkyl radicals is described. Both alkyl and benzofused compounds can be accessed directly from easily prepared acyclic precursors. Enantiomerically enriched sulfur‐based heterocycles were formed through an SHi process with inversion of configuration at the sulfuratom. Cyclization
描述了基于在硫原子上被芳基或烷基自由基的分子内均质取代(S H i)合成环状亚磺酸酯和亚磺酰胺的通用且有效的方法。烷基和苯并稠合的化合物都可以直接从容易制备的无环前体中获得。对映体富集的硫基杂环是通过S H i过程形成的,硫原子上的构型反转。前手性自由基的环化进行的立体化学结果各不相同,具体取决于传入自由基的大小。2-吡啶基和2-喹啉基会生成联芳基化合物,这是由于攻击芳基亚磺酸盐的邻位而不是亲硫取代引起的。
Biodiesel synthesis from the esterification of free fatty acids and alcohol catalyzed by long-chain Brønsted acid ionic liquid
of fatty acid to methanol and reaction temperature, were investigated. The results indicated that the long-chain Brønsted acid IL showed high catalytic activity and fair reusability. Esterification was accomplished under the following optimized conditions: molar ratio of alcohols to FFA at 1.5 : 1, mole fraction of ionic liquid at 10%, 60 °C, and 3 h. The products could be separated from the catalyst
制备了长链布朗斯台德酸离子液体(IL)3-(N,N-二甲基十二烷基铵)丙烷磺酸对甲苯磺酸酯([DDPA] [Tos]),并通过FT-IR,1 H NMR,13 C进行了表征NMR,UV / vis和TGA。还确定了IL的H 0(哈米特函数)值。IL作为催化剂被用于由游离脂肪酸(FFA)催化合成生物柴油。影响因素,例如催化剂的种类和用量,反应时间,脂肪酸与脂肪酸的摩尔比甲醇和反应温度,进行了研究。结果表明,长链布朗斯台德酸IL表现出较高的催化活性和公平的可重复使用性。酯化反应在以下优化条件下完成:醇与FFA的摩尔比为1.5:1,离子液体的摩尔分数为10%,60°C和3 h。可以通过在室温下进行液-液双相分离将产物从催化剂体系中分离出来,产率为92.5%至96.5%。去除二氧化硫后,该催化剂可重复使用九次。水和酒精。因此,长链布朗斯台德酸IL具有从低成本原料(例如废油和木本植物油)合成生物柴油的良好潜力。
Combined oxygen-17 NMR spectra and oxygen-18 isotope effects in carbon-13 NMR spectra for oxygen labeling studies. Carbon .fwdarw. sulfur oxygen migration in the aqueous chlorination of mercapto alcohols
作者:J. F. King、S. Skonieczny、K. C. Khemani、J. B. Stothers
DOI:10.1021/ja00359a039
日期:1983.10
alcohols, namely, 3-mercapto-1-propanol and 2-mercapto-1-ethanol in /sup 18/O labeled D/sub 2/O. The reaction products are of the first compound are CH/sub 2/-CH/sub 2/-CH/sub 2/-O-Schemically bondOchemically bondO, in which the endocyclic oxygen is labeled; and Cl(CH/sub 2/)/sub 3/SO/sub 2/Cl, in which the absence of an O label is noted. The chlorination of 2-mercapto-ethanol proceeds without intramolecular
Evidence is presented which indicate that pyrolysis of N-(3-hydroxypropylthio)phthalimide gives 1,2-oxathiolan as a volatile product via an intermediate tentatively identified as a cyclic oligomer.