共查询到19条相似文献,搜索用时 62 毫秒
1.
2.
5.
高级脂肪胺合成新工艺的研究 总被引:3,自引:0,他引:3
通过对油脂一步法制备脂肪腈继而加氢合成脂肪工艺的探讨,研究了催化剂、反应温度、反应时间及氨气流量对反应产率的影响,确定了合理脂肪胺合成工艺流程及最佳工艺条件,所得脂肪腈的产率达94%,与传统脂肪胺合成工艺相比,具有流程短,产率高,无腐蚀性等优点。 相似文献
6.
7.
8.
IR中,脂肪腈~三氯甲烷溶液在2250cm~-1波数处显示特征的吸收。应用基线法测定其吸光度,可快速、简便地定量分析高级脂肪腈。 相似文献
9.
10.
11.
In this contribution, an evaluation of the potential of various homogeneous and heterogeneous catalysts for a selective hydrogenation of fatty nitriles toward primary amines is reported exemplified for the conversion of octanenitrile into octane‐1‐amine as a model reaction. When using heterogeneous catalysts such as the ruthenium catalyst Ru/C, the palladium catalyst Pd/C, and the platinum catalyst Pt/Al2O3, low selectivities in the hydrogenation are observed, thus leading to a large portion of secondary and tertiary amine side‐products. For example, when using Ru/C as a heterogeneous catalyst, high conversions of up to 99% are obtained but the selectivity remains low with a percentage of the primary amine being at 60% at the highest. The study further reveals a high potential of homogeneous ruthenium and manganese catalysts. When also taking into account economical considerations with respect to the metal price, in particular, manganese catalysts turn out to be attractive for the desired transformation and their application in the model reaction leads to the desired primary amine product with excellent conversion, selectivity, and high yield. Practical Applications: This work describes an optimized hydrogenation process for transforming fatty nitriles to their corresponding primary amines. In general, fatty amines belong to the most applied fatty acid‐derived compounds in the chemical industry with an annual product volume exceeding 800 000 tons per year in 2011 and are widely required in the chemical industry since such compounds are either directly used in home products such as fabric softeners, dishwashing liquids, car wash detergents, or carpet cleaners or in a broad range of industrial products, for example, lubricating additives, flotation agents, dispersants, emulsifiers, corrosion inhibitors, fungicides, and bactericides, showing additional major applications, e.g., in the detergents industry. Among them primary amines play an important industrial role. However, a major concern of current processes is the lack of selectivity and the formation of secondary and tertiary amines as side‐products. By modifying a recently developed catalytic system based on manganese as economically attractive and environmentally benign metal component an efficient and selective access to fatty amines when starting from the corresponding nitriles is achieved. For example, hydrogenation of octanenitrile leads to a synthesis of octane‐1‐amine with >99% conversion and excellent selectivity with formation of secondary and tertiary amine side‐products being suppressed to an amount of <1%. 相似文献
12.
研究了一系列取代苯甲醛、杂环醛和脂肪醛与盐酸羟胺在酸催化剂存在条件下合成相应腈的新方法,考察了原料配比、催化剂种类、反应时间、溶剂用量及温度等因素对反应的影响。结果表明,合成目标物的优化工艺条件为:n(醛)∶n(盐酸羟胺)=1.0∶1.4,催化剂为硫酸氢钠,相转移催化剂为四丁基溴化铵,135℃反应47 h,收率达68.6%7 h,收率达68.6%97.9%。具有生产成本低、反应条件温和、易于工业化生产的优点。 相似文献
13.
Hilmi Yavuzer Jianing Yang Harald Gröger 《European Journal of Lipid Science and Technology》2023,125(5):2200177
Recently, the capability of the aldoxime dehydratase from Bacillus sp. (OxdB) for the transformation of fatty aldoximes into fatty nitriles with impressive substrate loadings is reported. However, the substrate scope of this biocatalyst turned out to be limited in terms of the chain length with decanal oxime being the substrate with the longest well tolerated n-alkyl chain. Besides the increased bulkiness of the long-chain aldoximes, their strongly decreased water solubility represents a further hurdle for an efficient biotransformation. Addressing this challenge of an expanded substrate spectrum comprising long-chain fatty aldoximes, this work investigates the substrate solubility and enzyme kinetics in combination with molecular modeling in order to find an enzyme mutant being suitable for C12- to C16-aldoximes. Both, fatty aldoxime solubility in water and the active site of the wild-type enzyme OxdB are identified as critical issues for an efficient biotransformation of these substrates. The activity issue is addressed by a rational design of a mutant using a homology modeling as well as a molecular modeling software suitable for enzymes. With the resulting double mutant OxdB-F289A/L293A, this report can achieve successful biotransformations with the C12- to C16-aldoximes at substrate concentrations of 250 × 10−3 to 1000 × 10−3 m . For example, an excellent conversion of >99% is obtained with tetradecanal oxime. Practical applications: Fatty nitriles with a prolonged chain length of C12 or more are of high interest in industry due to their use for the production of fatty amines on large technical scale. As an alternative route, fatty nitriles can be generated from their aldoximes by means of an aldoxime dehydratase (Oxd) as biocatalyst. The conversion of long-chain fatty aldoximes, however, remained a challenge up to now. This work describes the optimization of the aldoxime dehydratase OxdB from Bacillus sp. for the dehydration of nonsoluble bulky fatty aldoximes. The created variant can convert long chain fatty aldoximes toward the corresponding nitrile as demonstrated for C12- to C16-nitriles. In addition, high conversion (of up to >99%) is achieved when operating at high substrate concentrations of up to 1000 × 10−3 m , thus making this approach interesting for industrial applications. 相似文献
14.
15.
16.
Mei-Xiang Wang 《Topics in Catalysis》2005,35(1-2):117-130
Recent advances in enantioselective biotransformations of nitriles utilizing nitrile-hydrolyzing microorganisms and enzymes are summarized in this article. Various examples of biocatalytic synthesis of highly enantiopure carboxylic acids including amino acids, hydroxyl acids, cyclopropanecarboxylic acids and amide derivatives and oxiranecarboxamides are presented. The enantioselectivity of the nitrile hydratases, nitrilases and amideses is discussed. 相似文献
17.
18.
We report a vinyl cyanation reaction of vinyl triflates and readily available 1,4-dicyanobenzene through a nickel-catalyzed reductive coupling process. The reaction is operated under mild conditions with remarkable functional-group compatibility. Cyclic vinyl triflates with various ring sizes and substituents at different positions all reacted smoothly. The synthetic utility is demonstrated by the derivatization of pharmaceutical and natural compounds, a scale-up synthesis, and various functional group transformations. Preliminary mechanistic studies demonstrate that vinyl triflates are more reactive than 1,4-dicyanobenzene towards the oxidative addition to nickel catalyst. 相似文献
19.
本文叙述了脂肪腈催化氢化反应机理及常用抑制剂的作用机理,并用试验的方法对氨,氨水及碱水的作用性能进行了比较。 相似文献