Super-acidic Perfluorinated Resinsulfonic Acid (Nafion-H) Catalysis in Organic Synthesis

研究了超强酸全氟磺酸Nafion-H在有机合成中的催化应用。Nafion-H是商品化Nafion-K离聚物的酸形式，是一种高酸性（Ho ~（12））固体催化剂，在催化活性、热稳定性和耐化学性方面上级传统的树脂磺酸如磺化聚苯乙烯。Nafion-H催化剂在广泛的液相和气相反应中有效，包括芳核上的亲电取代、醇的脱水、重排、Nafion-H及其相关的全氟烷基磺酸不仅是强得多的酸，而且在腐蚀性环境中和高达210℃的温度下也是稳定的。此外，已经提供了使用不溶性树脂作为催化剂的具体优点：i）通常通过简单过滤容易将副产物与主反应产物分离; ii）防止反应性物质或官能化物质的分子间反应。 ...更多信息 通过模拟高稀释条件，可对不同类别的试剂进行重复使用; iii）可重复使用回收的试剂以及消除使用挥发性或有毒物质。目前开发的方法提供了优异的产率，易于分离的产品，和容易再生的催化剂没有任何活性损失。此外，反应混合物的后处理极其简单，包括固体催化剂的过滤（其可在简单再生后再使用）。仅需要催化量的催化剂，而不是与羟基或NH基团结合的常规刘易斯酸催化剂所需的通常化学计量量。使用不溶性树脂作为催化剂的具体优点包括通过模拟高稀释条件来防止活性物质或官能团的分子间反应。1.超强酸全氟树脂磺酸（Nafion-H）在有机合成中的催化作用Nafion-H已被证明是有机反应中有用和通用的酸催化剂。它在广泛的液相和气相反应中是有效的，包括醇的脱水、重排、芳核上的亲电取代和聚合。特别是，目前开发的方法为通过Nafion-h催化的环苄基化合成大环化合物提供了一系列应用.开发功能化的Nafion衍生物我们已经开发了一种有效和方便的方法，用于使用Ce（IV）或Cr（III）浸渍的Nafion-K催化剂使用各种助氧化剂将缩聚芳烃氧化为醌，其能够非常容易地进行，得到良好至中等的产率。利用功能化的Nafion衍生物可以实现各种类型的有机转化。少

The catalytic applications of Nafion-H, a superacidic perfluororesinsulfonic acid in organic synthesis are investigated. Nafion-H, the acid form of a commercial Nafion-K ionomer, is a highly acidic (Ho ≧-12) solid catalyst superior to conventional resinsulfonic acids such as sulfonated polystylenes in its catalytic activity, thermal stability and chemical resistance.Nafion-H catalyst is effective in a wide range of liquid and gas phase reactions, including electrophilic substitutions on aromatic nuclei, dehydration of alcohols, rearrangements, and polymerizations and so on. Nafion-H and related perfluoroalkanesulfonic acids are not only much stronger acids but sre also stable in corrosive enviroments and at temperature up to 210℃. Furthermore specific advantage of using insoluble resins as catalysts have been provided i) ease of by-product separation from the main reaction product usually by simple filtration ; ii) prevention of intermolecular reaction of reactive species or functional … More groups by simulating high dilution conditions ; iii) the possibility of reusing recovered reagents as well as eliminating the use of volatile or noxious substances. The presently developed procedure provides an excellent yield, easy isolation of the products, and ready regeneration of the catalyst without any loss of activity. Furthermore, the workup of the reaction mixture is extremely simple, involving filtration of the solid catalyst (which can be reused after simple regeneration). Only a catalytic amount of catalyst was needed instead of the usual stoichiometric quantity required for the conventional Lewis acid catalysts that bind to the hydroxyl droup or NH group. Specific advantages of using insoluble resins as catalysts include the prevention of intermolecular reactions of reactive species or functional groups by simulating high dilution conditions.1. Super-acidic perfluorinated resinsulfonic acid (Nafion-H) catalysis in organic synthesis Nafion-H has been shown to be useful and versatile acid catalyst for organic reactions. It is effective in a wide range of liquid and gas phase reactions, including dehydration of alcohols, rearrangements, electrophilic substitutions on aromatic nuclei, and polymerizations. Especially, the presently developed procedure provides a range of application for the synthesis of macrocycles by Nafion-h catalyzed cyclibenzylation.2. Development of functionalized Nafion derivatives We have developed an efficient and convenient procedure for oxidation of polycondensed aromatic hydrocarbons to quinones with Ce (IV) or Cr (III) impregnated Nafion-K catalyst using various co-oxidants, which are enable to proceed quite readily, giving good to moderate yields. The use of functionalized Nafion derivatives can be achieved various type of organic transformation. Less