相转移催化法合成醚

本文在文献的基础上,对聚乙二醇作相转移催化剂合成醚的反应进行了研究。以聚乙二醇为相转移催化剂合成醚的反应,多数是在固-液相条件下进行,液-液相条件仅见于碘甲烷的反应。对于一些活泼的氯代烃,例如2,4-二硝基氯苯同亲核性较强的酚类采用液-液相转移催化法就能得到满意的结果。     

相转移催化法合成芳基-烷基醚

芳香族醚类合成的经典方法通常采用Williamson^[1]法.该法反应条件比较苛刻,某些醚类的产率较低.相转移催化法合成醚类已有不少报导^[2-4].由于相转移催化法具有反应温度低、产率高、操作简单等优点,引起了人们的重视.我们应用相转移催化法,按下述反应合成了十一种芳基-烷基醚,其中Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ为新的化合物.     

Oxidation of Benzyl Ethers via Phase Transfer Catalysis

A convenient procedure for the oxidation of benzyl ethers to benzoate esters is reported. Potassium permanganate in dichloromethane with phase transfer catalysis by triethylbenzylammonium chloride (TEBAC) affords products regiospecifically in fair to excellent yields.     

A New High Yield Preparation of Benzyl Phenethyl Ethers by Phase Transfer Catalysis

A phase transfer method to prepare benzyl phenethyl ethers from electron-rich benzyl halides and 2-phenylethanols supporting electron-withdrawing groups is described. The yields are excellent, in contrast to the very low ones previously reported for the same kind of compounds prepared by other ways.     

Organic Synthesis Using Ptc-41: Synthesis of Cyclic Ethers Using Phase Transfer Catalysis

The reaction of (1) and (2) uith (3a)² 2nd (3b)³ under liquid-liquid (L-L) and solid-liquid (3-L) phase transfer (PT) conditions furnish the corresponding (4) and (6) respectively and the reaction of (2) with (5) gives dioxolane derivative (7)     

相转移催化下苄基醚选择性间接电氧化的研究

研究了相转移催化剂（Ｂｕ４ＮＨＳＯ４）作用下，Ｃｒ（Ⅵ）／Ｃｒ（Ⅲ）间接氧化还原体系电氧化苄基醚。实验结果表明，苄基醚可选择性地高产率氧化为苯甲醛，阳极液中Ｃｒ（Ⅲ）可以循环使用。     

逆相转移催化

主要介绍一种国内未见专题报道的逆相转移催化 (InversePhaseTransferCatalysis ,简称IPTC)技术 ,介绍该技术的定义、特点及典型应用     

Mesomorphic Crown Ethers

Studies on mesomorphic crown ethers, their analogs, published during the past two decades'are briefly summarized and correlated. Speicific features of mesophase formation, as influenced by the structure of the macrorings, are analyzed. The effect of structural factors on formation of various types of liquid crystals is discussed. Published data on prediction of formation of columnar mesophases in cyclic polyethers using quantitative molecular parameters are analyzed. Synthetic routes to such compounds are briefly presented. Particular attention is given to structure, properties, and possible applications of mesomorphic macrocycles.     

New Trends in Asymmetric Phase Transfer Catalysis

Phase Transfer Catalysis (PTC) is a powerful tool to perform reactions in a practical fashion, both in laboratory and industrial scale. Significant cost savings and major process improvements can be achieved in reactions performed under PTC conditions. In the last few years remarkable results in stereoselective reactions were achieved using chiral, non-racemic quaternary ammonium salts. Moreover, the use of bulky, chiral phosphate anions paired with achiral cations to generate lipophilic ion pairs allowed to design new avenues for the stereoselective construction of important building blocks. Hydrogen bond interactions were also shown to provide new pathways for asymmetric nucleophilic substitutions using insoluble reagents under PTC conditions. This Review will focus on recent advances in developing practical synthetic routes to construct molecules in a stereoselective fashion under PTC conditions.     

生色冠醚

本文介绍了各种类型的生色冠醚,对一些品种的特性和用途作了详细讨论。     

金属络合物的相转移催化分析与分离

以可简单分离回收、可反复使用为目标，详细介绍了相转移催化的变化发展过 程．通过对溶剂的选择，使得催化剂选择性地溶解在某一液相中，而使产物溶解在 另一液相中，如水-有机两相催化体系；通过温度的变化，简单地实现了在较高温 度下反应为均相体系以提高催化剂的活性，而在较低温度下实现了催化剂与产物不 相溶使得催化剂得以简单分离，如温控型水-有机两相催化体系、氟-有机两相催化 体系、温控型含氟催化剂、温控型有机金属催化剂等．     

Phase Transfer Catalysis Preparation of Acyl Isothiocyanates

The use of phase transfer catalysis, PTC, for nucleophillic substitution reactions is well documented.^1,2 Included among these reactions is the preparation of both alkyl³ and aryl⁴ thiocyanates. However, PTC reactions at an acyl carbon are much less common. Brándstróm⁵ has reported the preparation of acyl azides and Weber⁶ has used PTC to prepare benzoyl cyanide. Recently Illi⁷ has used PTC to acylate sterically crowded phenols.     

N,N-二烯丙基甲基胺的相转移催化合成

相转移催化剂;聚乙二醇-400;N;N-二烯丙基甲基胺的相转移催化合成     

线型聚氧乙烯化合物的相转移催化反应

线型聚氧乙烯化合物具有良好的相转移催化能力。以其作为相转移催化剂,不仅来源丰富,价廉无毒,化学稳定性好,而且反应条件温和,操作简便,产率也较高,是相转移催化反应中理想的冠醚替代物。文中综述了线型聚氧乙烯化合物作为相转移催化剂在有机合成中的应用进展,并对其相转移催化作用进行了讨论。     

Phase Transfer Catalysis Preparation of Aryl Thioethers

Phase transfer catalyzed displacement of halogen from activated aromatic rings by thiophenoxide ion has formed aryl thioethers in good yield.     

逆向相转移催化在有机合成中的应用

系统地总结了逆向相转移催化在有机合成中的应用,逆向相转移催化的作用在于逆向相转移催化剂能将底物分子从有机相转移至水相中发生反应,着重介绍了几种典型的逆向相转移催化剂如吡啶及其衍生物;杯芳烃;环糊精及其衍生物,水溶性过渡金属配合物在有机合成中的应用。     

聚乙二醇相转移催化剂在Perkin反应中的催化作用

本文以聚乙二醇(PEG)为相转移催化剂,对Perkin反应进行了研究。实验结果表明:聚乙二醇在Perkin反应中有明显的催化作用,平均分子量为600的聚乙二醇催化效果较好;PEG-600可使Perkin反应产率提高10％以上;反应时间显著缩短;PEG-600用量1％mol左右为宜。