金属卟啉催化空气氧化甲基环己烷制备甲基环己醇和甲基环己酮

报道了通过金属卟啉选择性催化空气氧化甲基环己烷制备甲基环己醇和甲基环己酮的方法.在金属锰卟啉催化下,甲基环己烷被空气氧化为3种甲基环己酮的异构体、1-甲基环己醇和2-甲基环己醇.考察了不同反应条件和金属卟啉结构对甲基环己烷氧化反应转化率和选择性的影响.与四苯基锰卟啉相比较，烷氧基取代的金属锰卟啉为催化剂时，虽然反应转化率降低了，但明显提高了甲基环己醇和甲基环己酮的选择性.且金属上的取代基团体积越大,反应的转化率越高，同时选择性较高.以金属卟啉5,10,15,20-四(对庚烷氧基苯基)锰卟啉为催化剂，反应的转化率可以达到20%，甲基环己醇和甲基环己酮的总选择性为76%.

Preparation of methylcyclohexanol and methylcyclohexanone from aerobic oxidation of methylcyclohexane catalyzed by metalloporphyrins

The method for the preparation of methylcyclohexanone and methylcyclohexanol via selective aerobic oxidation of methylcyclohexane catalyzed by metalloporphyrin was reported for the first time.Catalyzed by Mn(Ⅲ) porphyrin, methylcyclohexane could be oxidized by air.The products were three isomers of methylcyclohexanone, 1-methylcyclohexanol and 2-methylcyclohexanol. The effect on the conversion and selectivity was investigated when reaction conditions or porphyrin structure were changed.With the alkoxyl substituting metalloporphyrins as catalysts,the selectivity of methylcyclohexanone and methylcyclohexanol was better than using TPPMnOAc.Moreover, the larger the substitute’s volume, the higher the conversion, and selectivity still remained satisfactory.Using 5,10,15,20-tetra(para-heptaneoxylphenyl) porphyrin manganese as catalyst, the conversion was up to 20% and the overall selectivity of methylcyclohexanone and methylcyclohexanol was 76%.