可见光诱导氯化铁催化苯并噁嗪-2-酮与烷烃的脱氢偶联烷基化反应  

Photoinduced FeCl_3-catalyzed Cross-Dehydrogenative Alkylation of Benzoxazin-2-ones with Alkanes

作　　者：辛翠[1] 蒋俊 邓紫微 欧丽娟 何卫民 Xin Cui;Jiang Jun;Deng Zi-Wei;Ou Li-Juan;He Wei-Min(Key Laboratory of Food&Environment&Drug Monitoring and Testing of Universities in Hunan Province,Hunan Police Academy,Changsha 410138,China;School of Materials Science and Engineering,Hunan Institute of Technology,Hengyang 421002,China;School of Chemistry and Chemical Engineering,University of South China,Hengyang 421001,China;National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]湖南警察学院食药环及毒品检验技术湖南省普通高等学校重点实验室,长沙410138 [2]湖南工学院材料科学与工程学院,衡阳421002 [3]南华大学化学化工学院,衡阳421001 [4]南京林业大学林木生物质低碳高效利用国家工程研究中心,南京210037

出　　处：《化学学报》2024年第11期1109-1113,共5页Acta Chimica Sinica

基　　金：湖南省教育厅科学研究项目(22B0944)资助。

摘　　要：以价廉易得的烷烃为烷基化试剂,发展了一种基于配体-金属电荷转移(ligand-to-metal charge transfer)机制的可见光诱导铁催化苯并噁嗪-2-酮烷基化新方法.以氯化铁为光催化剂,空气为氧化剂,四丁基氯化铵为氢原子转移促进剂,在390nm可见光诱导下实现了苯并噁嗪-2-酮C(sp^(2))—H键和烷烃C(sp^(3))—H键之间的交叉脱氢偶联反应,构建新的C(sp^(2))—C(sp^(3))键,实现烷基化苯并噁嗪-2-酮衍生物的高效合成.该方法具有反应条件绿色温和、位点选择性高、操作简单等优点,在生物活性分子后续结构修饰中具有较高的应用价值.Homogeneous visible-light photoredox catalysis has emerged as a powerful tool in modern organic synthesis,which utilizes inexhaustible light to facilitate carbon-carbon and carbon-heteroatom bond formation under eco-friendly and mild conditions.Due to the incapablity of most organic compounds to absorb visible light,homogeneous photocatalysts such as precious metals(rhodium and iridium-complexes)and elaborate organic dyes were often employed through their visible light-driven electron/energy transfer to sensitize organic molecules in photoredox catalysis.However,these photocatalysts are not conducive to large-scale production due to the relatively high cost.Iron is an ideal candidate for economical and eco-friendly catalysis because of its abundant availability and nontoxicity.Recently,iron-photocatalyzed bond formation reactions via ligand-to-metal charge transfer(LMCT)have attracted huge attention.Functionalized benzoxazin-2-ones are important N-heterocycles found in many natural products,bioactive molecules and pharmaceuticals.Among these benzoxazin-2-one derivatives,alkylated benzoxazin-2-ones have received significant attention due to their valuable biological and pharmacological activities.From a synthetic point of view,the direct C—H alkylation of benzoxazin-2-ones represents one of the most straightforward and efficient methods for producing alkylated benzoxazin-2-ones due to its high atom and step economy.Alkanes are low cost and abundant feedstock materials,which have been widely used as the alkylation reagents in organic synthesis.In the present work,we report the development of iron-catalyzed C—H alkylation of benzoxazin-2-ones with alkanes via photoinduced LMCT.With FeCl_(3)as the photocatalyst,ambient air as the oxidant,tetrabutylammonium chloride as the promoter,a series of 3-alkylbenzoxazin-2-ones were efficiently synthesized under mild and eco-friendly conditions.The chlorine radical generated in situ serves as a hydrogen atom-transfer reagent.In addition,the present reaction can be smoothly

关 键 词：光催化 烷烃 苯并噁嗪-2-酮 烷基化反应 配体-金属电荷转移 

分 类 号：O64[理学—物理化学]