Hydrogen Peroxide Oxidation of Olefins into Carboxylic Acids Catalyzed by Heteropoly Acids

从合成和工业的角度来看，烯烃转化为相应的羧酸具有很大的兴趣。本研究的目的是为了开发将烯烃转化为羧酸的催化剂。以12-钨磷酸和3个等量的十六烷基氯吡啶为原料，在35%的过氧化氢条件下，以叔丁醇为溶剂，容易合成的杂多酸，特别是三（十六烷基吡啶）12-钨-磷酸（CWP）， [pi-C_5H_5N^+(CH_2)_<15>CH_3]_3[PW_<12>O_<40>]^<3->，可催化烯烃氧化裂解成羧酸。与CWP类似，钨酸（H_2WO_4）在控制pH为4 ~ 5的叔丁醇中也能有效地进行相同的反应。这种方法从工业方面特别有意义，因为无毒的钨可以用作催化剂。进一步，以CWP为催化剂，考察了多种有机底物的过氧化氢氧化，得到了以下结果：1。α、β -不饱和羧酸在pH控制在6-7的水中氧化得到收率高的环氧羧酸。2.1,2-二醇转化为相应的羧酸。3. -二醇经过氧化脱氢得到内酯，收率相当高。4. 醇和二醇的仲醇官能团转化为相应的羰基化合物。12钨磷酸与氯化十六烷基吡啶复合催化过氧化氢氧化是一种新的杂多酸催化反应。

The conversion of olefins into the corresponding carboxylic acids has much interest from synthetic and industrial points of view. This work is directed toward the development of catalyst to carry out the conversion of olefins into carboxylic acids. Heteropoly acids, especially tris(cetylpyridinium)12-tungsto- phosphate(CWP), [pi-C_5H_5N^+(CH_2)_<15>CH_3]_3[PW_<12>O_<40>]^<3->, synthesized readily from 12-tungstophosphoric acid and 3 equivalents of cetylpyridinium chloride, were found to catalyze the oxidative cleavage of olefins into carboxylic acids with 35% hydrogen peroxide under homogeneous conditions using tert-butyl alcohol as solvent. In the similar manner as CWP, tungstic acid (H_2WO_4) was also effective for the same reaction in tert-butyl alcohol controlled to pH 4-5. This method is especially of interest from the industrial aspect, since non-toxic tungsten can be used as the catlyst.Further, hydrogen peroxide oxidation of a variety of organic substrates was examined by using CWP as catalyst, and the following results were obtained.1. alpha,beta-Unsaturated carboxylic acids were oxidized in water controlled to pH 6-7 to give epoxy carboxylic acids in good yields. 2.1,2-Diols were converted into the corresponding carboxylic acids. 3. alpha,omega-Diols underwent the oxidative dehydrogenation to give lactones in fair to good yields. 4. sec-Alcoholic functions of alcohols and diols were converted into the corresponding carbonyl compounds.The hydrogen peroxide oxidations catalyzed by 12-tungstophosphoric acid combined with cetylpyridinium chloride are attractive as a new catalysis of heteropoly acids.