共查询到20条相似文献,搜索用时 93 毫秒
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简述了三烃基锡氢化物在有机合成中对 C-X 键的选择性还原、不饱和基团的加成、分子间和分子内的碳碳偶联、钯催化甲酰化、开环和扩环等反应的作用。 相似文献
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具有生物活性的三烃基锡化合物的研究进展 总被引:2,自引:0,他引:2
主要对具有生物活性的三烃基锡化合物的研究进行回顾,其中包括不具有含硅基团的单一三烃基锡化合物、混合三烃基锡化合物,具有含硅基团的单一三烃基锡化合物、混合三烃基锡化合物,以及其它结构类型的三烃基锡化合物的生物活性研究。 相似文献
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薄层色谱法测定有机锡化合物和三苯基膦的纯度 总被引:1,自引:0,他引:1
本文报导了薄层色谱法用于工业产品三苯基氯化锡、三苯基氢氧化锡、三苯基醋酸锡和三苯基膦的纯度测定。该方法简便、快速,而且准确度也符合工业生产要求。 相似文献
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Liposomes were prepared by the supercritical reverse phase evaporation method developed in our laboratory using various phospholipids with different hydrocarbon chains. The effects of the length of alkyl chain and number of unsaturated bonds of phospholipids on the properties of liposomal membranes were examined through trapping efficiency measurements, transmission electron microscopic observations, and osmotic response measurements. The trapping efficiency for water-soluble drugs of liposomes prepared by our method was greatly higher than that of liposomes prepared by the conventional Bangham method. Liposomes prepared using unsaturated phospholipids showed a high trapping efficiency compared with those prepared using saturated phospholipids. In addition, the trapping efficiency of liposomes prepared using 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC), a complex phospholipid with both saturated and unsaturated alkyl groups, had a value intermediate between L-alpha-dipalmitoyl-phosphtidylcholine (DPPC), a saturated phospholipid, and L-alpha-dioleoylphosphatidylcholine (DOPC), an unsaturated phospholipid. That is, the trapping efficiency of liposomes was dependent on the number of unsaturated bonds rather than the alkyl chain length of phospholipid molecule and it increased with increasing bulkiness of the molecule. The osmotic response was higher for liposomes prepared using unsaturated phospholipids than for those formed by saturated phospholipids. 相似文献
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Ursula Biermann Jürgen O. Metzger 《European Journal of Lipid Science and Technology》2008,110(9):805-811
Alkyl‐branched fatty compounds are of interest for industrial products in the cosmetics and lubricant areas. In this review, clay‐ and zeolite‐catalyzed isomerizations of unsaturated fatty compounds, especially of oleic acid, are discussed. While clay‐catalyzed reactions give most complex mixtures of dimeric fatty acids and of monomeric so‐called “isostearic acid”, the zeolite‐catalyzed process yields preferentially an isomeric mixture of isostearic acids having the methyl branch on the 8–14 positions of the alkyl chain. Synthetically useful additions of alkyl radicals can only be performed on ω‐unsaturated fatty compounds, whereas perfluoroalkyl iodides were added to fatty compounds with terminal as well as internal double bonds using electron transfer‐initiated radical addition reactions. Electrophilic additions of alkyl carbenium ions generated by decomposition of alkyl chloroformates by ethylaluminum sesquichloride give well‐defined alkyl‐branched oleochemicals with good yields. 相似文献
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Katharina Strohmeier Sigurd Schober Martin Mittelbach 《Journal of the American Oil Chemists' Society》2014,91(7):1217-1224
An easy and efficient method for the separation of saturated and unsaturated fatty acid mono alkyl esters, prepared from animal fat, was developed. The most efficient separation was achieved by the use of solvents such as methanol and acetone at low temperatures. The dilution of the alkyl esters with 10 times the amount of solvent (10:1 v/w) and storage of the mixture for 4 h at ?22 °C could be defined as optimum conditions. After filtration of the saturated fraction at the corresponding temperature very pure fractions were obtained. For fatty acid methyl esters deriving from tallow, with an initial content of saturated fatty acids of almost 50 %, a saturated ester fraction with only 5 % unsaturated fatty acids and an unsaturated ester fraction with about 9 % of saturated fatty acids could be obtained. The solvent easily could be recovered by distillation. In addition fatty acid ethyl, 1‐propyl, 2‐propyl, 1‐butyl, tert‐butyl and 3‐methyl‐1‐butyl esters were prepared and separated into saturated and unsaturated fractions. All fractions were analyzed according to the fatty acid compositions and showed similar or slightly worse results compared to the methyl esters. The cold filter plugging points of the unsaturated fractions were measured, showing the lowest value for the unsaturated methyl ester fraction at ?26 °C. The fractionation with the use of solvents is an easy tool in order to obtain fatty acid alkyl esters with excellent cold temperature behavior out of animal fat. 相似文献
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An organocatalytic Michael addition of protected 2‐amino‐1‐nitroethanes to α,β‐unsaturated aldehydes followed by treatment with TFA afforded 4‐substituted 3‐nitro‐1,2,3,4‐tetrahydropyridines with good diastereoselectivity and excellent enantioselectivity. Good yields were observed in the case of β‐aryl‐substituted α,β‐unsaturated aldehydes as the substrates, while moderate yields were obtained when β‐alkyl‐substituted α,β‐unsaturated aldehydes were used. 相似文献
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Glyceryl ethers were identified and quantified by the GLC analysis of their alkyl iodide (special conditions described), acetonide
and allyl alkyl ether derivatives. The acetoxy-mercuri-methoxy derivatives of unsaturated glyceryl ether swere separated from
saturated glyceryl ethers by TLC and the fractions were analyzed as alkyl iodides. Monoiodides from saturated glyceryl ethers
and diiodides from unsaturated glyceryl ethers were also separated by TLC and then analyzed. Allyl alkyl ethers had small
retention volumes and these derivatives were separated into pure fractions by preparative GLC. Ozonides were reduced either
to alcohols with lithium aluminum hydrodie or to aldehydes with dimethyl sulfide. The alcohols were converted to mono- and
diiodides which were separated by TLC and analyzed by GLC. The recovery of n-C6 and n-C7 monoiodides was not quantitative. Diiodides and aldehydes were both identified and quantified by GLC. Ozonolysis data suggest
that the 16∶1 glyceryl ethers from dogfish liver oil contain 7,8 and 9,10 isomers and the 18∶1 glyceryl ethers contain 9,10
and 11,12 isomers.
Presented in part at the AOCS Meeting, Philadelphia, October 1966. 相似文献
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H. Reinheckel R. Gensike F. Falk G. Sonnek 《European Journal of Lipid Science and Technology》1969,71(9):792-795
Preparation of Branched Carboxylic Acids Free from Isomers A method for the preparation of branched saturated and unsaturated carboxylic acids, free from isomers, from tertiary γ-lactones by means of alkyl aluminium chlorides is reported. Saturated branched carboxylic acids were obtained in high yields by the reaction with ethyl aluminium chloride, whereas the reaction with diethyl aluminium chloride yielded the unsaturated acids. Splitting of lactones with mixtures of both the ethyl aluminium chlorides gave mixtures of saturated and unsaturated acids. The structure of the unsaturated carboxylic acid was determined by hydrogenation, ozonolysis, iodine value and gas chromatography. 相似文献
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对油墨用(烷基)酚醛树脂的化学改性研究进行了综述。分别讨论了(烷基)酚醛树脂的环氧化改性、松香改性、石油树脂改性及其他含不饱和键的化合物或聚合物改性,主要包括改性原理、改性方法及其应用情况。 相似文献
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Francesc Comelles Joaquín Snchez‐Leal Juan Jos Gonzlez 《European Journal of Lipid Science and Technology》2005,107(5):291-296
The influence of the fatty acid structure on the formation of transparent gels with lamellar liquid crystal structure, for systems composed of an anionic surfactant, fatty acid, diethyleneglycol ethyl ether and water, was investigated. The influence of the alkyl chain length, for both saturated and unsaturated fatty acids, was considered. Moreover, for a given alkyl chain length, the influence of polyunsaturation was also considered. The results obtained indicate that with saturated fatty acids, it is not possible to form lamellar liquid crystals with the appearance of transparent gels, and that in the case of unsaturated acids, the influence of the alkyl chain length is more important than the degree of unsaturation. 相似文献
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The polymerization of ε-caprolactone (CL) using triphenyltin acetate has been investigated. Polymers with broad MWD were obtained
in almost quantitative yield. After an initial induction period, the polymerization showed zero order kinetics with respect to monomer and nearly first order with respect to catalyst. The mechanism of the propagation reaction
is proposed to proceed via an ester alcoholysis, with initiation by traces of water. The zero order kinetics are explained
as follows: the tin catalyst is coordinated by the cyclic lactone, monomer addition to the polymer chain in the rate-determining
step results in formation of an acyclic ester link, which is no longer a strong donor, and leads to a coordinatively unsaturated
tin species. 相似文献
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Jae Hwan Lee Atikorn Panya Mickaël Laguerre Christelle Bayrasy Jérôme Lecomte Pierre Villeneuve Eric A. Decker 《Journal of the American Oil Chemists' Society》2013,90(2):225-232
Effects of the alkyl chain length of rosmarinate alkyl esters on the oxidative stability in photosensitized oil-in-water (O/W) emulsions were determined by lipid hydroperoxides and headspace volatile analyses. Antioxidant capacities of 20 μM rosmarinate esters with alkyl chain length of 0, 4, 8, 12, 18, and 20 were tested in O/W emulsion containing stripped soybean oil, Tween 20 as an emulsifier, and riboflavin as a photosensitizer. Synergistic or antagonistic effects of 20 μM α-tocopherol in the presence of rosmarinate alkyl esters were also determined. Samples containing rosmarinate with 4 and 8 alkyl esters showed lower lipid hydroperoxides and headspace volatiles than those without rosmarinate and those with 0, 12, 18, and 20 alkyl esters, which indicates that phenolic free radical scavengers showed antioxidant capacities non-linearly in riboflavin photosensitized O/W emulsions. Antagonistic rather than synergistic effects were observed in all rosmarinate alkyl esters with α-tocopherol in current conditions although rosmarinates with 4, 8, and 12 alkyl esters showed better antioxidant capacities than those with other alkyl chain length. The results of this study clearly showed that rosmarinates need the proper length of non-polar groups to show optimum antioxidant capacities in O/W emulsions with Tween 20 as an emulsifier under riboflavin photosensitization. 相似文献