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

研究了超酸性全氟磺酸钠- h在有机合成中的催化应用。Nafion-H是一种商用Nafion-K离子单体的酸形式，是一种强酸性（Ho≧-12）固体催化剂，其催化活性、热稳定性和耐化学性优于磺化聚苯乙烯等传统树脂磺酸。Nafion-H催化剂在广泛的液相和气相反应中有效，包括芳香核的亲电取代、醇的脱水、重排和聚合等。Nafion-H和相关的全氟烷磺酸不仅是强得多的酸，而且在腐蚀环境和高达210℃的温度下也很稳定。此外，使用不溶性树脂作为催化剂的特殊优点是：1)通常通过简单的过滤，副产物易于从主要反应产物中分离出来；ii)通过模拟高稀释条件，防止活性物质或官能团的分子间反应；Iii)重复使用回收试剂的可能性以及消除挥发性或有毒物质的使用。目前开发的程序提供了一个很好的收率，容易分离的产品，和催化剂的再生准备没有任何损失的活性。此外，反应混合物的处理非常简单，涉及固体催化剂的过滤（可以在简单再生后重复使用）。只需要催化量的催化剂，而不需要通常的化学计量量，传统的刘易斯酸催化剂需要与羟基或NH基团结合。使用不溶性树脂作为催化剂的特殊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。超酸性全氟树脂磺酸（Nafion-H）在有机合成中的催化作用已被证明是一种用途广泛的有机反应酸性催化剂。它在广泛的液相和气相反应中有效，包括醇的脱水、重排、芳香核的亲电取代和聚合。该方法为Nafion-h催化环苄基化合成大环提供了广泛的应用前景。我们开发了一种以Ce （IV）或Cr （III）浸渍的Nafion- k为催化剂，使用多种助氧化剂，将多凝聚芳烃氧化成醌的高效、简便的方法。利用功能化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