【作者】 王华；

【导师】 康彦彪；

【作者基本信息】 中国科学技术大学 ， 有机化学， 2021， 博士

【摘要】 在有机合成中,氧化和氧化-还原反应是应用非常广泛的化学反应。通过氧化反应可以将众多诸如烃类的基础工业原料转化为各种含氧化合物,比如酚、醇、醛、酮、羧酸等。在相反的还原过程中,可以将这些氧化产物,尤其是羰基化合物,还原为醇类化合物。这些含氧化合物是天然产物、农药化学品以及生物医药中间体的重要结构单元。以甲苯为代表的芳烷烃是重要的化工原料,通过苄位氧化可以使之转化为芳基醛、酮、酸等。尽管目前发展的苄位亚甲基氧化成酮或醇的方法已经非常成熟,但是以下基本问题依然有待深入探索:1.氧化的绿色化,特别是利用分子氧作为氧化剂。2.氧化产物的高效利用新方法。基于我们课题组对芳烷烃氧化的研究兴趣,本论文开展了以下四部分的研究内容:1.发展了可以克服缺电子抑制效应和配位抑制效应的杂环苄位氧化新策略。利用催化量的N-羟基邻苯二甲酰亚胺和亚硝酸叔丁酯的协同作用,氧气为绿色氧化剂,我们发展了非金属催化的芳杂环苄位好氧氧化成酮的方法,在温和的条件下合成一系列的N-杂环基团的酮。该反应提供了克服杂苄基自由基氧化中的缺电子抑制作用和产物抑制作用的有力方法。2.发展了经由卤化的苄位氧化成醇的方法。在可见光条件下,利用常见、易得的可回收试剂(4-三氟甲基)二氯碘苯实现二芳基甲烷类活性化合物间接可控的氧化成醇的反应,避免了高活性苄位亚甲基氧化成酮的副反应。3.发展了苄位氧化产物还原偶联转化成二醇的新催化体系。利用我们课题组发现的有机催化剂CBZ6,高效地把醛,酮和亚胺等经由光促进的频哪醇偶联反应转化为相应的产物。该方法为苄位氧化产物的深度转化提供了一条便捷的途径,也为苄位的氧化和还原接力转化提供了有效的途径。另外,在对烷基芳烃的氧化产物的系统研究中,我们还利用醛及其衍生物作为催化剂,实现了光促进的自由基聚合。更多还原

【Abstract】 Oxidation and redox reactions are widely used chemical reactions in the field of organic synthesis.Many basic industrial raw materials such as hydrocarbons can be converted into various oxygen-containing compounds,such as phenols,alcohols,aldehydes,ketones,carboxylic acids and so on via oxidation reaction.On the contrary,these oxidation products,especially carbonyl compounds,can be reduced to alcohol compounds in the reduction process.These oxygen-containing compounds are important structural units of natural products,pesticide chemicals,and biomedical intermediates.Aromatic alkanes,such as toluene,are important chemical raw materials,which can be converted into aryl aldehydes,ketones,acids by oxidation at the benzylic position.Although the currently developed methods for the oxidation of benzylic methylene to ketones or alcohols are very mature,the following basic issues still need to be explored in depth:1.Green oxidation of the above,especially using molecular oxygen as an oxidant.2.New methods for efficient utilization of oxidation products.Based on the research interest of our research group in the oxidation of aromatic alkanes,the following four parts of research content has been carried out:1.A new strategy for heterocyclic benzylic oxidation that can overcome the electron-deficiency inhibition effect and the coordination inhibition effect has been developed.Utilizing the synergistic effect of catalytic amount of N-hydroxyphthalimide and tert-butyl nitrite,and oxygen as a green oxidant,we have developed a metal-free catalyzed method for aerobic oxidation of aromatic heterocycles to ketones.A variety of N-heterocyclic ketones could be prepared under relatively mild conditions.This reaction provides a powerful method for overcoming the electron-withdrawing inhibition effect as well as product-inhibition effects in heterobenzylic radical oxidation.2.A method for oxidation of halogenated benzyl positions to alcohols has been developed.The commonly and easily available recyclable reagent dichloro(4-(trifluoromethyl)phenyl)-λ3-iodane is used to achieve the indirect and controllable oxidation reaction of active diarylmethanes to alcohols under visible light conditions,which avoids the side reaction of high-activity benzylic methylenes oxidation to ketones.3.A new catalytic system for the conversion of benzyl oxidation products into diols via reductive coupling has been developed.Aldehydes,ketones and imines can be efficiently converted into the corresponding products using the organic catalyst CBZ6,discovered by our research group,via photo-promoted pinacol coupling reactions.This method provides a convenient way for the deep conversion of the benzyl oxidation product,and also provides an effective way for the benzylic position oxidation and reduction relay conversion.In addition,in the systematic study of the oxidation products of alkyl aromatic hydrocarbons,we also used aldehydes and their derivatives as catalysts to achieve light-accelerated free radical polymerization.更多还原