Iwahama T, Yoshino Y, Keitoku T, Sakaguchi S, Ishii Y
Department of Applied Chemistry, Faculty of Engineering & High Technology Research Center, Kansai University, Suita Osaka, Japan.
J Org Chem. 2000 Oct 6;65(20):6502-7. doi: 10.1021/jo000760s.
Highly efficient catalytic oxidation of alcohols with molecular oxygen by N-hydroxyphthalimide (NHPI) combined with a Co species was developed. The oxidation of 2-octanol in the presence of catalytic amounts of NHPI and Co(OAc)2 under atmospheric dioxygen in AcOEt at 70 degrees C gave 2-octanone in 93% yield. The oxidation was significantly enhanced by adding a small amount of benzoic acid to proceed smoothly even at room temperature. Primary alcohols were oxidized by NHPI in the absence of any metal catalyst to form the corresponding carboxylic acids in good yields. In the oxidation of terminal vic-diols such as 1,2-butanediol, carbon-carbon bond cleavage was induced to give one carbon less carboxylic acids such as propionic acid, while internal vic-diols were selectively oxidized to 1,2-diketones.
开发了一种通过N-羟基邻苯二甲酰亚胺（NHPI）与钴物种结合，利用分子氧对醇进行高效催化氧化的方法。在70℃下，于乙酸乙酯中，在催化量的NHPI和Co（OAc）₂存在下，在大气二氧气氛中对2-辛醇进行氧化，得到2-辛酮，产率为93%。通过添加少量苯甲酸，即使在室温下也能使氧化反应显著增强并顺利进行。在没有任何金属催化剂的情况下，伯醇被NHPI氧化，以良好的产率形成相应的羧酸。在末端邻二醇（如1,2-丁二醇）的氧化中，会引发碳-碳键断裂，生成少一个碳的羧酸（如丙酸），而内邻二醇则被选择性氧化为1,2-二酮。
