Nitrogen derivatives (Amides,diamides, nitriles,primary amines and oxides)

Without a doubt the nitrogen derivatives are the most broadly diversified family of fatty acid derivatives. Today they account collectively for perhaps 400 million pounds of products per year in the USA alone. Although fatty amides may be produced by a large number of synthetic routes, industrially only two are of any commercial importance. Diamides are the difunctional analogs of simple amides, and a typical one that is in medium scale production volume is ethylene bis(stearamide). Industrially, the production of fatty nitriles in the fatty acid derivative industry is exclusively by ammonolysis of fatty acids at temperatures somewhat above those required to produce amides, or roughly, 300–320 C. Both vapor phase catalytic and liquid phase ammonolysis processes may be employed. Nitriles have limited uses as such, but find their utility as fatty derivative intermediates only. The primary amines, RNH₂, are produced industrially by the catalytic hydrogenation of nitriles. The general conditions for the conversion of nitriles to primary amines with a minimum content of secondary or tertiary amines is with nickel catalyst using an excess of ammonia at relatively low temperatures (130–140 C). Amine oxides are derived from tertiary amines by a controlled reaction with hydrogen peroxide. In addition to tertiary amines, the monoalkyl diethoxylated amines can be considered as in the same class. These are made by the addition of ethylene oxide to primary amine. Two moles of ethylene oxide can be added without catalyst. Additional ethoxylation does require a basic catalyst. These amines, besides having end uses of their own, can be converted to amine oxides or can be converted to ethoxylated quaternary ammonium salts.     

Test procedure for evaluation of catalysts for nitrile reduction

A procedure was developed that examines the effectiveness of nickel catalysts for the hydrogenation of fatty nitriles to amines. Rates of reaction, selectivity, and olefinic reduction were the parameters studied. The procedure can be used for new catalyst screening and is ideally suited for quality assurance testing of production catalysts. It involves the reduction of nitriles to amines at 410°F (210°C) and 500 psig using a .2% Ni loading level. A mixture of primary and secondary amines is obtained which is characteristic of the catalyst’s selectivity. Both sponge and supported nickel catalysts were tested using tallow nitriles as the feedstock.     

脂肪伯胺的生产

介绍脂肪伯胺的生产方法、产品规格、质量控制。讨论反应温度、反应压力、催化剂的浓度、氨循环速率、冷凝温度对脂肪腈的反应速率、得率、能量消耗的影响。     

Heterogeneous Raney Nickel and Cobalt Catalysts for Racemization and Dynamic Kinetic Resolution of Amines

Raney metals were studied as heterogeneous catalysts for racemization and dynamic kinetic resolution (DKR) of chiral amines, as an alternative to metals like palladium or ruthenium. Both Raney nickel and cobalt were able to selectively racemize various chiral amines with high selectivity. In the racemization of benzylic primary amines, the minor formation of side products, e.g., secondary amines, can be suppressed by varying the hydrogen pressure. In the racemization of aliphatic amines over Raney catalysts, the selectivity is very high, with the enantiomeric amine as the sole product. DKR of racemic aliphatic amines can be performed with immobilized Candida antarctica lipase B and Raney nickel in one pot; for 2‐hexylamine, a yield of 95 % of the acetylated amide was achieved, with 97 % ee. Attention is devoted to the compatibility of the enzyme and the metal catalyst during the DKR. For benzylic primary amines, a two‐pot process is proposed in which the liquid is alternatingly shuttled between two vessels containing the solid racemization catalyst and the biocatalyst. After 4 such cycles, the amide of (R)‐1‐phenylethylamine was obtained with 94 % yield and more than 90 % ee.     

脂肪腈加氢制备单烷基二甲基叔胺催化剂的研究

通过对催化剂活性组分的筛选,钯/碳(Pd/C)催化剂对脂肪腈与二甲胺反应制备单烷基二甲基叔胺有良好的选择性。采用浸渍-沉淀法制备出负载型Pd/C催化剂,考察了制备过程中溶液体系的pH值和浸渍时间对Pd/C催化剂性能的影响。结果表明:该溶液体系在pH值7.9和浸渍15 h~18 h的条件下得到的Pd/C催化剂对脂肪腈催化加氢制备单烷基二甲基叔胺有较好的催化性能。     

Selective hydrogenation of nitriles to imines over a multifunctional heterogeneous Pt catalyst

Imines and their derivatives are versatile synthetic intermediates for the industrial preparation of both bulk and fine chemicals and for pharmaceuticals, but preparing these compounds efficiently through direct hydrogenation of nitriles are hindered by overhydrogenation to secondary amines. Here we report a highly efficient multifunctional catalyst system for selective hydrogenation coupling of nitriles to secondary imines using a heterogeneous Pt catalyst that was deposited on a nickel‐based metal‐organic framework (MOF) containing DABCO. The catalyst showed excellent synergy in promoting the hydrogenation of a variety of nitriles, giving significantly improved activity and selectivity (up to >99% yield) even under atmospheric pressure of H₂. It is suggested that the Lewis base (DABCO) sites on the Ni‐MOF inhibit further hydrogenation of the imines. The influence of H₂ pressure, reactant concentration, stirring speed, and reaction temperature was investigated. The kinetics and mechanism of hydrogenation of benzonitrile (BN) by the Pt/Ni‐MOF catalyst has been studied. The reaction showed a first‐order dependence on both BN concentration and H₂ pressure. A kinetic model was proposed based on the mechanism of nitriles hydrogenation and compared with experimental observations. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3565–3576, 2014     

The Reductive Amination of Aldehydes and Ketones and the Hydrogenation of Nitriles: Mechanistic Aspects and Selectivity Control

This review deals with two of the most commonly used methods for the preparation of amines: the reductive amination of aldehydes and ketones and the hydrogenation of nitriles. There is a great similarity between these two methods, since both have the imine as intermediate. However, due to the high reactivity of this intermediate, primary, secondary and/or tertiary amines are obtained (often simultaneously). The relation of the selectivity to different substrate structures and reaction conditions is briefly summarised, the main focus being on the catalyst as it is the most significant factor that governs the selectivity. Different mechanisms are discussed with the view to correlate the structure of the catalyst and, more particularly, the nature of the metal and the support with selectivity. The crucial point is the presumed location of the condensation and hydrogenation steps.     

高级脂肪胺及其衍生物的应用前景

简要介绍高级脂肪胺的种类、合成路线及性能。重点综述了高级脂肪伯胺和叔胺的应用,主要是在制备阳离子表面活性剂、非离子表面活性剂和两性表面活性剂等方面的应用;同时概述了仲胺、二胺、多胺及其衍生物的应用。最后对高级脂肪胺及其衍生物的发展提出了几点建议。     

脂肪醇醚的催化胺化及其季铵化衍生物的制备

描述了用带气相循环的１０Ｌ反应系统进行醇醚（ＡＥＯ３）的催化胺制备醚叔胺的工艺以及醇醚叔胺的氯甲烷季铵化反应,制得两种醇醚叔胺及其季铵化衍生物,其中双烷基醚胺含量〉７０％,单烷基醚含量〉６５％,两种季铵盐活化物浓度为４０％,未反应胺〈１．３％。     

第三组分对Cu-Ni脂肪醇胺化催化剂的影响

目前制备单长链烷基二甲基叔胺的主要工艺是由脂肪醇和二甲胺在脱氢 加氢类催化剂的作用下进行胺化反应。研究了加入第三金属元素组分对以Cu和Ni为活性组分、以碳酸钙为载体的催化剂选择性的影响。发现金属元素La和Ba的加入,提高了催化剂的选择性,降低了反应产物中高沸物双十二烷基甲基叔胺的含量。Al的加入却大大降低了催化剂的选择性。     

The selective hydrogenation of acetonitrile on supported nickel catalysts

The catalytic behavior of several supported nickel catalysts in the hydrogenation of acetonitrile was studied. It was established that the selectivity of this process is greatly influenced by the nature of the support used. Catalysts consisting of nickel supported on acidic supports catalyzed the formation of condensation products, diethyl- and triethylamine. Nickel supported on basic supports was highly selective with respect to the formation of the primary amine, ethylamine. It was shown that modification of the intrinsic acidity of alumina-based supports by the application of alkaline additives has a large impact on the selectivity of the resulting catalyst. Based on the results obtained from measurements on a basic catalyst diluted with either an acidic or a basic support, a dual-function mechanism is suggested. The mechanism implies that the hydrogenation function of the catalyst is located on the metal, while the acid function, responsible for the condensation reactions, is located on the support. A mechanism, accounting for the occurrence of the acid-catalyzed condensation reactions, is proposed.     

Fatty methyl ester hydrogenation to fatty alcohol part I: Correlation between catalyst properties and activity/selectivity

Fatty alcohols, derived from natural sources, are commercially produced by hydrogenation of fatty acids or methyl esters in slurry-phase or fixed-bed reactors. One slurry-phase hydrogenation of methyl ester process flows methyl esters and powdered copper chromite catalyst into tubular reactors under high hydrogen pressure and elevated temperature. In the present investigation, slurry-phase hydrogenations of C₁₂ methyl ester were carried out in semi-batch reactions at nonoptimal conditions (i.e., low hydrogen pressure and elevated temperature). These conditions were used to accentuate the host of side reactions that occur during the hydrogenation. Some 14 side reaction routes are outlined. As an extension of this study, copper chromite catalyst was produced under a number of varying calcination temperatures. Differences in catalytic activity and selectivity were determined by closely following side reaction products. Both activity and selectivity correlate well with the crystallinity of the copper chromite surface; they increase with decreasing crystallinity. The ability to follow the wide variety of side reactions may well provide an additional tool for the optimized design of hydrogenation catalysts.     

Tris(acetylacetonato)rhodium(III)‐Catalyzed α‐Alkylation of Ketones, β‐Alkylation of Secondary Alcohols and Alkylation of Amines with Primary Alcohols

The tris(acetylacetonato)rhodium(III) catalyst is shown to be a versatile catalyst in the presence of DABCO (1,4‐diazabicyclo[2.2.2]octane) as ligand for the α‐alkylation of ketones followed by transfer hydrogenation, for the one‐pot β‐alkylation of secondary alcohols with primary alcohols and for the alkylation of aromatic amines in the presence of an inorganic base in toluene.     

Recent Advances in Transition Metal‐Catalyzed Hydrogenation of Nitriles

Amines are important building blocks possessing various applications in agrochemicals, the fine chemical industry, pharmaceuticals, materials science and biotechnology. The catalytic hydrogenation of nitriles is an important reaction for the one‐step synthesis of diverse amines. However, significant amounts of side product formation during the course of the reaction is a major issue. In recent years, an enormous amount of work has been reported using both homogeneous and heterogeneous transition metal complex catalysts for the selective reduction of nitriles. Transition metal catalysts are the most crucial factor that controls the selectivity in this reaction. Therefore, transition metal catalysts are the central point of this review. We have also briefly discussed the effect of reaction parameters, selectivity to different substrate structures and reaction mechanisms. This review provides an overview of recent developments in transition metal‐catalyzed nitrile reduction along with examples which highlight its vast potential in organic transformations.

     

不饱和脂肪酸甲酯加氢Cu-Ni/SiO_2催化剂的研究

针对铜镍二元催化剂活性低、难过滤及容易造成金属在加氢产物中残存等问题,开展了用于不饱和脂肪酸甲酯加氢的高活性、易过滤、低金属残存Cu Ni/SiO2催化剂的研究。以特制的、具有固定物性参数的SiO2做载体,是本催化剂的特点。通过控制铜镍比和不陈化解决了金属残存问题,且红外光谱表明,产物不发生异构。催化剂制备方法和条件为:并流沉淀,趁热过滤;铜镍总量与SiO2质量比为4∶1;铜镍质量比为1∶2 5;焙烧温度350℃左右,焙烧时间3h。该催化剂优点为:不需单独还原易于保存,反应速率快,加氢活性高,催化剂用量为甲酯质量的0 5%,1MPa氢压,反应30min条件下,产物碘值可由110降到5以下。     

Chemoselective Hydrogenation of α,β‐Unsaturated Nitriles

The chemoselective hydrogenation of cinnamonitrile to 3‐phenylallylamine proceeds with up to 80% selectivity at conversions of >90% with Raney cobalt and up to 60% selectivity with Raney nickel catalysts. Best results were obtained with a doped Raney cobalt catalyst (RaCo/Cr/Ni/Fe 2724) in ammonia saturated methanol at 100 °C and 80 bar. Major problems are the formation of hydrocinnamonitrile and of secondary amines, and overreduction to 3‐phenylpropylamine. Important parameters are the catalyst type and composition, the solvent type and the presence and concentration of ammonia. The catalytic system tolerates functional groups like OH, OMe, Cl, CO, but not aromatic nitro groups. Preliminary experiments indicate that other unsaturated nitriles with di‐ or trisubstituted CC bonds are also suitable substrates.     

Liquid phase hydrogenation of adiponitrile over directly reduced Ni/SiO2 catalyst

Liquid phase hydrogenation of adiponitrile (ADN) to 6-aminocapronitrile (ACN) and hexamethylenediamine (HMD) was investigated on Ni/SiO₂ catalysts prepared under different conditions. In this reaction, the highly reactive imine intermediate forms condensation byproducts by reacting with the primary amine products (ACN and HMD). A highly dispersed Ni/SiO₂ catalyst prepared by the direct reduction of Ni(NO₃)₂/SiO₂ was found to suppress the condensation reactions by promoting the hydrogenation of adsorbed imine, and it gave excellent hydrogenation activity and primary amine selectivity. Addition of NaOH increased the primary amine selectivity to 79% at the ADN conversion of 86%.     

脂肪伯胺的合成及工业化研究进展

有机胺在化工、医药、生命科学等领域有着广泛的应用,可作为染料、日用品原料以及抗生素、生物碱、临床医学药物等。在众多胺类化合物中,伯胺是最基础的结构单元,其应用在胺类化合物中也最为广泛。随着经济社会的快速发展与人们生活质量的提高,伯胺,尤其是脂肪伯胺的市场需求量与日俱增,脂肪伯胺的合成及工业化制备已成为一个重要领域。经过了数十年的发展,脂肪伯胺的生产技术已经取得了巨大的成果,但仍然存在一些问题,例如苛刻的反应条件、催化剂性能不足、污染严重、工艺复杂等。本文以脂肪伯胺的工业生产以及热点制备方法为研究对象,针对工业上制备脂肪伯胺的工艺进行了汇总归纳(包括卤代烃胺化法、醇还原胺化法,腈加氢还原法、烯烃直接胺化法、羧酸胺化法等),并举例说明各制备方法在工业生产中的实际应用,分析比较各工艺方案的优劣,并对当前的研究热点——通过羰基还原胺化制备脂肪伯胺的方法进行了研究进展的阐述,指出该制备方法在未来工业应用的潜力与挑战。     

脂肪叔胺制备技术进展

主要从3方面综述了脂肪叔胺制备技术的研发进展。介绍了脂肪叔胺的市场情况及主要用途,其主要作为制备阳离子表面活性剂和两性离子表面活性剂的重要中间体,这2类表面活性剂的主要品种可作为消毒杀菌剂、缓蚀剂、抗静电剂、织物整理剂以及个人护理用品中的活性成分等;重点阐述了脂肪叔胺的制备工艺过程,此工艺的技术关键是催化剂的制备,包括催化剂组分的筛选及其制备过程,目前主要采用的是多元金属复合催化剂,多以Cu与其他金属元素复合;简要回顾了脂肪醇催化胺化技术的发展概况,并对脂肪叔胺制备技术的进一步发展提出了建议。     

Controlled Synthesis of the Henry Reaction Products: Nitroalcohol Versus Nitrostyrene by a Simple Change of Amino-Groups of Aminofunctionalized Nanoporous Catalysts

A synthetic method for controlling the Henry reaction products from nitrostyrene to nitroalcohol in heterogeneous catalysis by a simple change of the catalytic sites in organoamine-functionalized mesoporous catalysts is reported. The synthesis resulted in either β-nitrostyrene or β-nitroalcohol by simple change of the types of amine functional groups in the amine-functionalized mesoporous catalysts from primary amines into secondary or tertiary.