Development of a New Catalytic System for the Carbon Radical Generation and Its Application to Organic Syntheses.

实现高效和选择性地将碳氢化合物转化为有用的化学物质是合成化学的一个雄心勃勃的目标。利用N-羟基邻苯二甲酰亚胺（NHPI）作为碳自由基生成催化剂（CRPC），可以确定多种化合物的C-H键生成碳自由基的催化方法，开辟有机合成的新前景。以NHPI为催化剂，在温和条件下实现了烷烃的新型好氧氧化反应，其转化率和选择性均优于传统的自氧化反应。这种氧化方法提供了一系列重要的含氧化合物的入口。特别地，用分子氧以高转化率和选择性将环己烷直接转化为己二酸的成功作为环境友好的方法极大地有益于化学工业，因为目前通过硝酸氧化生产己二酸引起氮氧化物的释放，氮氧化物是严重的空气污染物质。此外，NHPI催化烷基苯的有氧氧化，因此，各种羧酸的高效合成由该方法。通过从KA油生成α-羟基过氧化物获得己内酯和己内酰胺前体，而不形成任何废物。该方法适用于烷烃与NO_2反应生成硝基烷烃的反应。最后，建立了一种新的烯烃与烷烃和O_2共存的催化烷氧基化反应，称为烯烃的催化烷氧基化反应。α-羟基-γ-内酯是一种很难用常规方法合成的化合物，在NHPI催化剂的作用下，醇、烯烃与氧气反应，可以很容易地合成α-羟基-γ-内酯。NHPI可作为极性反转催化剂用于烯烃与醛的氢酰化反应。

The achievement of highly efficient and selective transformations of hydrocarbons to useful chemical substances is an ambitious goal in synthetic chemistry. It is interesting to open up a new vista in organic synthesis and to confirm the catalytic method for the carbon radical generation from a C-H bond of a wide variety of compounds by the use of N-hydroxyphthalimide (NHPI) which serves as a carbon radical producing catalyst (CRPC). By employing NHPI as the catalyst, a novel aerobic oxidation of alkanes, which surpasses the conventional autoxidations in conversion and selectivity, has been achieved under mild conditions. This oxidation method provides entry to a diverse array of significant oxygen-containing compounds. In particular, a success in the direct conversion of cyclohexane to adipic acid with dioxygen in high conversion and selectivity has greatly benefited the chemical industry as an environmentally benign process, because the current production of adipic acid via nitric acid oxidation causes the evolution of nitrogen oxides that are serious air-polluting materials. In addition, the NHPI catalyzes the aerobic oxidation of alkylbenzenes, thus various carboxylic acids were efficiently synthesized by this method. Caprolactone and caprolactam precursors were obtained through generation of alpha-hydroxyperoxides from KA-oil without formation of any wastes. This new methodology is applicable to the functionalization of alkanes to afford nitroalkanes by allowing them to react with NO_2. Finally, a new type of reaction for the concomitant introduction of alkanes and O_2 to alkenes, which is referred to as catalytic oxyalkylation of alkenes, has been established. α-Hydroxy-γ-lactones, which are very difficult to synthesize by conventional methods, are easily prepared by the reaction of alcohols, alkenes and O_2 under the influence of the NHPI catalyst. The NHPI can be used as a polarity-reversal catalyst for hydroacylation of alkenes with aldehydes.