共查询到20条相似文献,搜索用时 15 毫秒
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实验室中合成叔硫醇缺少简便方法。用叔醇和氢溴酸与硫脲直接反应是目前采用的方法。Lee和Akerstrom曾用此法合成了叔硫醇,但碳原子数没超过七个。Sprague及Kresze分别用干燥氯化氢及盐酸代替氢溴酸也合成了叔硫醇,但产率不高。本文提出了用叔醇、硫酸与硫脲反应来制备叔硫醇的方法,并合成了六个叔硫醇。 相似文献
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Xin Mu Yu Shibata Yusuke Makida Prof. Gregory C. Fu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(21):5915-5918
Vicinal stereocenters are found in many natural and unnatural compounds. Although metal-catalyzed cross-coupling reactions of unactivated alkyl electrophiles are emerging as a powerful tool in organic synthesis, there have been virtually no reports of processes that generate, much less control, vicinal stereocenters. In this investigation, we establish that a chiral nickel catalyst can mediate doubly stereoconvergent alkyl–alkyl cross-coupling, specifically, reactions of a racemic pyrrolidine-derived nucleophile with cyclic alkyl halides (as mixtures of stereoisomers) to produce vicinal stereocenters with very good stereoselectivity. 相似文献
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Yuta Sato Akito Osada Dr. Narihito Ogawa Dr. Yuichi Kobayashi 《European journal of organic chemistry》2023,26(28):e202300403
The Cu(OTf)2-catalyzed alkyl–alkyl coupling reaction of a secondary substrate MeCH(OSO2Py)CH2CH2C6H4(4-OMe) with a nBuLi-based reagent prepared by transmetalation with MgBr2 ⋅ THF3 in THF produced a coupling product in 74 % yield. The use of soluble MgBr2 ⋅ THF3 in THF was required for this reaction. This method was applied to sBuLi and Ph(CH2)4Li. In contrast, transmetalation of MeLi with soluble MgCl2 ⋅ THF2 in THF produced the Me reagent, which was reactive for the coupling reaction. The reaction proceeded with inversion of the stereogenic carbon. Furthermore, (S)-14-methyloctadecan-2-one, a sex pheromone produced by lichen moths, was synthesized. 相似文献
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Ning-Kai SHU Zhi-Cheng XU Zi-Yu LIU Zhi-Qiang JIN Jian-Bin HUANG Lei ZHANG Lu ZHANG 《物理化学学报》2017,33(4):803-809
利用悬挂滴方法研究了2,5-二乙基-4-壬基苯磺酸钠(292)、2,5-二丙基-4-壬基苯磺酸钠(393)和2,5-二丁基-4-壬基苯磺酸钠(494)在空气-水表面和正癸烷-水界面的扩张流变性质,考察了时间、界面压、工作频率及体相浓度对扩张弹性和粘性的影响。研究发现,在低表面活性剂浓度条件下,表面吸附膜类似弹性膜,其强度由膜内分子的相互作用决定;高浓度下体相与表面间的扩散交换过程控制表面膜的性质。油分子的插入导致界面吸附分子之间相互作用的削弱,扩散交换过程主导界面膜性质;但随着短链烷基长度增加,油分子的影响变小。表面膜的强度在吸附达到平衡前已经决定,而界面膜在吸附饱和后仍然随界面分子重排而变化。 相似文献
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Akira Matsumoto Katsuyuki Watanabe Tsukasa Matsumoto Hiroyuki Aota Mikio Hirabayashi Akinori Kameyama 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1889-1893
Abstract Polymerizations of several diallyl alkyl isocyanurates were investigated to explore in more detail the steric effect observed in the polymerization of triallyl isocyanurate [3, 5], as compared to its isomer triallyl cyanurate, by changing alkyl groups from methyl, propyl, hexyl, and octyl up to lauryl. The rate of polymerization, the gel point, the cyclization constant, and the primary chain length were evaluated. For example, the primary chain length increased with an increase in the bulkiness of the alkyl group as expected, although in the polymerization of diallyl lauryl isocyanurate it decreased as a reflection of reduced rate of propagation due to the enhanced steric effect arising from a very bulky lauryl group. 相似文献
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Xiao-Lin Wu Yan-Ping Chu Yu-Ping Huang Zhi-Cheng Xu 《Journal of Dispersion Science and Technology》2016,37(12):1738-1744
Dilational rheological behaviors of adsorption layers of three surfactants, sodium 2-hydroxy-3,5-dioctyl benzene sulfonate (C8C8), sodium 2-hydroxy-3-octyl-5-decyl benzene sulfonate (C8C10), and sodium 2-hydroxy-3-octyl-5-dodecylbenzenesulfonate (C8C12) formed at air–water and decane–water interfaces, have been investigated as a function of concentration and frequency (0.002–0.1 Hz) by the oscillating bubble/drop method. The experimental results show that the dilational moduli of hydroxy-substituted alkyl benzenesulfonates are obviously higher than those of the common surfactants, because the interfacial interactions between alkyl chains are improved drastically by the unique arrangement of C8C8 molecules at the interface. However, the moduli at the decane–water interface are much lower than those at the surfaces because decane molecules will insert into the surfactant molecules adsorbed at the interface and destroy the interactions between alkyl chains. With an increase in the number of carbon atom of 5-alkyl, the surface dilational modulus decreases because the orientation of the surfactant molecules at the surface varies from parallel to tilt. On the other hand, the diffusion-exchange process dominates the interfacial behavior and the interfacial modulus improves with the increase in the length of the alkyl chain. 相似文献
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A. F. Kireev I. V. Rybal'chenko V. I. Savchuk V. N. Suvorkin I. A. Tipukhov B. A. Khamidi 《Journal of Analytical Chemistry》2002,57(8):708-716
The main goal of chemical analytical monitoring in the destruction of chemical weapons is to identify highly toxic compounds of similar structures in long homologues series. The difficulties with the identification are due to a wide range of possible structures of such compounds with similar mass-spectral patterns. This necessitates the development of special approaches to the interpretation of analytical data. The paper presents the data of experimental studies of specific features of chromatographic–mass spectrometric behavior of 150 substances of the specified classes. The account of these data can improve the reliability of the identification. 相似文献
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《Colloids and surfaces. A, Physicochemical and engineering aspects》2001,176(1):69-83
We review several key elements of alkyl polyglucoside (CmGn) microemulsion phase behavior. The low solubility of CmGn surfactants in oils such as alkanes makes producing CmGn microemulsions and subsequent study of their phase behavior difficult. Increasing the solubility of CmGn in oil is therefore helpful for the systematic study of CmGn-based microemulsion formulations. To this end, the role of cosurfactants in producing microemulsions with water, alkanes, and n-alkyl β-d-glucopyranosides is first discussed. Adding C10βG1 to mixtures of water–alkane–ethoxylated alcohol surfactants (CiEj) produces a region of the three-phase body (a ‘chimney’) that is independent of temperature; thus CmβG1 are not completely soluble in the co-oil formed of alkane and CiEj at higher temperatures. Then, through a novel approach using oxygenated ether oils (CkOC2OCk), microemulsions are formed with water, CkOC2OCk, and CmβG1 and the phase behavior studied as a function of temperature and composition. Increased CmβG1 solubility in the more hydrophilic ether oils produces patterns of phase behavior in water–CkOC2OCk–CmβG1 mixtures that are identical to those observed in water–alkane–CiEj mixtures. Using the water–ether oil–CmβG1 mixtures as a base case, the role of CmGn surfactant structure in setting CmGn microemulsion phase behavior is explored. The solubility of the α-d anomer (n-alkyl α-d-glucopyranosides, CmαG1) in water is much less than that of the β-d surfactant, and these solubility boundaries extend to high surfactant and oil concentrations in water–CkOC2OCk–CmαG1 mixtures. Adding CmG2 compounds to water–CkOC2OCk–CmβG1 mixtures shifts the phase behavior to high temperatures, again demonstrating the extreme hydrophilic nature of the sugar headgroup. Finally, adding small amounts of ionic alkyl sulfate surfactants to water–CkOC2OCk–CmβG1 mixtures dramatically reduces the total amount of surfactant needed to form a single-phase microemulsion. 相似文献
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《Journal of Dispersion Science and Technology》2013,34(6):569-581
A screening method using factorial design has been used to arrive at a workable formulation for self-emulsification of alkyl ketene dimer, AKD. The emulsification was performed at 60°C which is above the melting temperature of the AKD. Good results were obtained with a combination of calcium dodecylbenzene sulphonate and an alcohol ethoxylate as surfactants and a small amount of dodecanol as cosurfactant. The three amphiphilic compounds were dissolved in the AKD and the mixture was added to the aqueous phase under gentle stirring. The mechanism behind the easy formation of the AKD-in-water emulsion is discussed. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(13):3704-3708
Because of the lack of effective alkylating reagents, alkyl etherification of olefins with general alkyl groups has not been previously reported. In this work, a variety of alkyl diacyl peroxides and peresters generated from aliphatic acids have been found to enable the first iron‐catalyzed alkyl etherification of olefins with general alkyl groups. Primary, secondary and tertiary aliphatic acids are suitable for this reaction, delivering products with yields up to 97 %. Primary and secondary alcohols react well, affording products in up to 91 % yield. 相似文献