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

在合成化学中，将碳氢化合物高效、选择性地转化为有用的化学物质是一个雄心勃勃的目标。利用n -羟基邻苯酰亚胺（NHPI）作为碳自由基生成催化剂（CRPC），为多种化合物的C-H键生成碳自由基开辟了新的有机合成领域。以NHPI为催化剂，在温和条件下实现了一种新型的烷烃好氧氧化反应，在转化率和选择性上均优于传统的自氧化反应。这种氧化方法提供了多种重要含氧化合物的入口。特别是，环己烷与二氧直接转化为己二酸的高转化率和选择性的成功，极大地有利于化学工业作为一个环境友好的过程，因为目前通过硝酸氧化生产己二酸导致氮氧化物的演变，这是一种严重污染空气的物质。此外，NHPI还能催化烷基苯的好氧氧化，因此可以高效地合成各种羧酸。已内酯和已内酰胺前体由ka油生成α -羟基过氧化物而不产生任何废物。该方法适用于使烷烃与NO_2反应而官能化生成硝基烷烃。最后，建立了一种烷烃与氧同时引入烯烃的新型反应，即烯烃催化氧烷基化反应。α-羟基-γ-内酯在NHPI催化剂的作用下，可以很容易地由醇类、烯烃和O_2反应制备出常规方法难以合成的α-羟基-γ-内酯。NHPI可作为烯烃与醛氢酰化反应的极性反转催化剂。

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.