生物质转化合成新能源化学品乙酰丙酸酯

生物质是唯一可替代化石资源获取液态燃料和化学品的可再生资源,近年来由生物质转化合成乙酰丙酸酯引起了研究者们越来越广泛的关注。乙酰丙酸酯是一类重要的化学中间体和新能源化学品,具有高的反应特性和广泛的工业应用价值。目前开发的从生物质资源出发转化合成乙酰丙酸酯的潜在合成途径可概括为4种:直接酸催化醇解法、经乙酰丙酸酯化、经5-氯甲基糠醛醇解和经糠醇醇解。本文分别介绍了这4种转化合成途径的化学反应过程及最新研究进展,从反应合成工艺、催化体系、经济可行性等方面评述了各自的特点与发展趋势,并分析了目前工业规模转化生物质合成乙酰丙酸酯仍面临的一些科学难点。最后,对今后该领域的研究前景进行了展望。     

生物质能源化学品乙酰丙酸酯

生物质能源是新兴的可再生能源,是仅次于煤、石油、天然气的第四大能源。乙酰丙酸酯是从生物质资源中获得的高附加值产物,是一类重要化工中间体与新能源化学品,其应用领域十分广泛,具有潜在的商业价值。本文介绍了乙酰丙酸酯的理化性质与用途,以生物质资源为原料制备乙酰丙酸酯的三种合成方法及其反应机理。最后分析了乙酰丙酸酯目前生产与应用的不足,并展望了乙酰丙酸酯未来开发和利用的发展趋势。     

混合溶剂中酶促合成维生素A乳酸酯

研究了混合溶剂中脂肪酶催化合成维生素A乳酸酯.首先对催化合成维生素A乳酸酯反应的脂肪酶和反应介质进行了研究,其次对影响合成维生素A乳酸酯反应的因素(温度、底物摩尔比、反应时间和酶量等)进行了探讨,优化了反应条件:在5 mL混合溶剂(叔丁醇/正己烷(v/v)=3:2)中,0.167 g维生素A醋酸酯和0.150g乳酸在25 mg脂肪酶Novozym 435催化下,在35℃、150 r/m in下反应6 h,产率可以达到52.19%,固定化酶可连续使用5次以上,产率仍达45%以上.     

芳甲叉双噁唑啉-铜络合物催化三氟甲基丙酮酸酯与吲哚的傅-克烷基化反应研究

报道了芳甲叉双噁唑啉-铜络合物催化三氟甲基丙酮酸酯对吲哚的傅-克烷基化反应,探讨了配体结构、溶剂、温度等因素对反应的影响.研究表明,反应表现出高活性和中等程度以上的对映选择性,吲哚环上取代基对催化反应有重要的影响.提供了一种合成含手性三氟甲基季碳吲哚化合物的新方法.     

聚乙烯吡啶(PVP)催化合成O-酰化乳酸酯的研究

本文利用聚乙烯吡啶（ｐｏｌｙｖｉｎｙｌ ｐｙｒｉｄｉｎｅ）为催化剂，对乳酸酯进行Ｏ－酰化反应，对影响反应的诸因素进行了讨论，产物的收率为７０－８０％。     

脂肪酸(酯)脱氧制备生物燃料研究现状

随着全球能源消耗量的增长,传统化石燃料等不可再生能源将日趋枯竭且环境污染等弊端日益突显.利用绿色、可再生生物质资源,尤其是脂肪酸(酯)脱氧转化制备液体燃料已成为全球关注的热点.脂肪酸(酯)脱氧过程中氢源的不同,直接影响脱氧的反应路径、效率和成本.鉴于此,本文根据氢源的不同,综合分析了近年来脂肪酸(酯)的直接加氢脱氧、原位加氢脱氧、脱羧脱羰等过程的研究进展.提出了未来脱氧过程的主要发展方向和研究重点,为商业化脱氧技术的开发提供新的助力.     

钯—膦—酸体系催化烯烃氢酯基化反应

众所周知,酯是重要的精细化工产品。有些酯可作水果香精,有些酯是高级酒香的重要成分,己二酸二辛酯和癸二酸二辛酯则是高级增塑剂。通常,酯是用羧酸和醇反应制得。若能利用来自石油化工厂的烯烃和CO代替得之不易的羧酸来生产酯类。将具有明显的实际意义。国外曾试探过许多过渡金属包括钴、铑、铱等的配位催化体系对烯烃进行氢酯基化的催化反应,其中以钯膦体系效果最佳。国内,已有二、三个研究小组对钯膦体系进行探索,但未见有关钯膦酸催化剂体系方面的报道。本文介绍我们在钯膦酸体系催化氢酯基化反应的一些实验结果。     

二丁基锡(IV)磺酸酯催化合成缩醛(酮)

用二丁基氧化锡与苯磺酸、甲磺酸反应制备了两种新的有机锡化合物——二丁基锡(IV)磺酸酯. 以二丁基锡(IV)磺酸酯作催化剂, 合成了一系列缩醛(酮), 并通过正交实验, 优化了有机锡催化缩醛(酮)合成反应的反应条件. 实验表明该催化反应产率高, 反应时间短, 催化剂用量少且能回收再利用.     

硫酸氢钠催化合成乳酸酯

研究一水硫酸氢钠在乳酸和不同醇酯化作用中的应用,合成了11种乳酸酯并测定了它们的沸程、折射率、IR和^1H NMR。     

二丁基锡（Ⅳ）磺酸酯催化合成缩醛（酮）

用二丁基氧化锡与苯磺酸、甲磺酸反应制备了两种新的有机锡化合物——二丁基锡（Ⅳ）磺酸酯．以二丁基锡（Ⅳ）磺酸酯作催化剂,合成了一系列缩醛（酮）,并通过正交实验,优化了有机锡催化缩醛（酮）合成反应的反应条件．实验表明该催化反应产率高,反应时间短,催化剂用量少且能回收再利用．     

Cobalt-Catalyzed Asymmetric Remote Borylation of Alkyl Halides

Enantioselective functionalization of racemic alkyl halides is an efficient strategy to assemble complex chiral molecules, but remains one of the biggest challenges in organic chemistry. The distant and selective activation of unreactive C−H bonds in alkyl halides has received growing interest as it enables rapid generation of molecular complexity from simple building blocks. Here, we reported a cobalt-catalyzed remote borylation of alkyl (pseudo)halides (alkyl−X, X=I, Br, Cl, OTs) with pinacolborane (HBpin) and presented a robust approach for the generation of valuable chiral secondary organoboronates from racemic alkyl halides. This migration borylation reaction is compatible with primary, secondary, and tertiary bromides, offering direct access to a broad range of alkylboronates. The extension of this catalytic system to the borylation of aryl halides was also demonstrated. Preliminary mechanistic studies revealed that this remote borylation involved a radical reaction pathway.     

Indium-mediated cleavage of diphenyl diselenide and diphenyl disulfide: efficient one-pot synthesis of unsymmetrical diorganyl selenides, sulfides, and selenoesters

A convenient and efficient method was developed for the synthesis of alkyl phenyl selenides, sulfides, and selenoesters in one-pot reaction by using indium metal. The reaction showed the selectivity for tert-alkyl, benzylic, and allylic halides over primary and secondary alkyl halides. For the reaction of primary and secondary alkyl iodides and bromides, the yields of selenides were improved by the addition of a catalytic amount of iodine.     

Rate Study of Samarium Diiodide Reduction of Alkyl Halides and 2-Heptanone

Rate constants directly measured from GC-analyzed method for SmI₂ reduction of alkyl halides were obtained. The rates increase in the orders of primary, secondary, tertiary RX and RCl < RBr < RI as expected. 2-Heptanone was chosen as the partner of alkyl halide in the samarium Barbier reaction. In the absence of HMPA, the reaction orders of alkyl halide and ketone were determined as first and zero order, respectively.     

绿色表面活性剂——烷基(聚)葡糖苷缔合结构体系

行近年来“绿色表面活性剂”烷基（聚）葡萄苷的研究在国际上越来越受重视。本文从表面吸附性能、水溶液的相行为、形成微乳液及与类脂物的作用等方面对烷基（聚）葡萄苷的研究进展作了综述。     

不同链长烷基芳基磺酸盐形成微乳液的性质

以Winsor相态图法和拟三元相图法研究了自制的3种不同链长烷基芳基磺酸盐在多组分体系中形成的微乳液的性质, 并考察了分子结构、无机盐和短链醇等的影响. 结果表明, 无机盐浓度的增加导致表面活性剂/正丁醇/正辛烷/NaCl/水形成的微乳液体系在一定温度下发生由WinsorⅠ→ WinsorⅢ→ WinsorⅡ型转变; 随着烷基芳基磺酸盐分子的长烷基链碳原子数的增加, 耐盐能力减弱, 增溶能力提高; 随着醇碳链的增大, 微乳区面积先增大后减小. 当烷基芳基磺酸盐分子结构固定时, 最大微乳液区域醇的选择依据符合Bansal理论. 醇的链长一定时, 随着烷基芳基磺酸盐分子的长烷基链碳原子数的增加, 微乳液的区域变小.     

A Structure–Activity Study of Nickel NNN Pincer Complexes for Alkyl‐Alkyl Kumada and Suzuki–Miyaura Coupling Reactions

A new series of Ni NNN pincer complexes were synthesized and characterized. The main difference among these complexes is the substituents on the side arm amino group(s). No major structural difference was found except for the C–N–C angle of the various substituents and the ‘pseudo bite angle’ of the complexes. Four new complexes were efficient for the alkyl‐alkyl Kumada reaction of primary alkyl halides, and among them, one complex was also efficient with secondary alkyl halides. The influence of the substituents on the catalytic performance of the Ni complexes in alkyl‐alkyl Kumada and Suzuki–Miyaura cross‐coupling reactions was systematically investigated. No correlation was found between the catalytic activity and the key structural parameters (C–N–C angle and ‘pseudo bite angle’), redox properties or Lewis acidity of the complexes.     

Kinetics of the Esterification Reaction Catalyzed by Lipase in W／O Microemulsions of Alkyl Polyglucoside

A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol,catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-butanol/cyclohexane/phosphate buffer solution. The restult shows that when the ratio of mol concentration of 1-butanol to 1-hexanoic acid is about 3.0,the initial rate V0 get the maximum values. This phenomenon was explained by the modified fishlike phase diagrams.     

直链醇、烷基苯气相色谱保留指数之比与其正辛醇/水分配系数的相关性

通过研究直链醇、烷基苯等有机物气相色谱保留指数与其正辛醇／水分配系数的关系得出,在极性相异固定相上保留指数之比Im/n与其正辛醇／水分配系数的对数值logkow之间有较好的线性相关性。因而由保留指数能很好的预测分配系数,从而为直链醇、烷基苯分配系数的测定提供了一种简便准确的新方法。     

Alkyl phosphines promoted reductive coupling of acyl cyanides: formation of O-acyl cyanohydrins

The reductive coupling of acyl cyanides promoted by alkyl phosphines has been discovered. Under mild reaction conditions, the substituted cyanohydrins were obtained in moderate to high yields by using trimethylphosphine or tributylphosphine as a promoter. The possible mechanism involved in the reaction was discussed on the basis of deuterium labeling and control experiments, indicating that one hydride transfer took place from alkyl phosphine to O-acyl cyanohydrin.     

Electrochemical Method for the Preparation of Dibromomethyl,Bis(bromomethyl), and Bis(dibromomethyl) Arenes

Electrochemical bromination of alkyl aromatic compounds by two-phase electrolysis yields the corresponding α, α-dibrominated products. The reaction has been carried out in a single-compartment electrochemical cell using aqueous sodium bromide (40–50%), containing a catalytic amount of HBr as electrolyte, and chloroform, containing an alkyl aromatic compound, as the organic phase with a Pt plate as anode at 10–15°C. Two-phase electrolysis results in high yields (70–90%) of dibromomethyl, bis(bromomethyl), and bis(dibromomethyl) arenes, depending upon the charge passed.