光氧化还原催化串联自由基加成反应构建1,4-二酮官能团化喹喔啉-2(1H)-酮衍生物  

Photoredox Catalytic Cascade Radical Addition to Construct 1,4-Diketone-Functionalized Quinoxalin-2(1H)-one Derivatives

作　　者：孙鑫[1] 屈超凡 马超蕊 赵筱薇[1,2] 柴国璧 江智勇[1,2] Sun Xin;Qu Chaofan;Ma Chaorui;Zhao Xiaowei;Chai Guobi;Jiang Zhiyong(International Scientific and Technological Cooperation Base of Chiral Chemistry,Henan University,Kaifeng,Henan 475004;School of Chemistry and Chemical Engineering,Henan Normal University,Xinxiang,Henan 453007;Key Laboratory of Tobacco Flavor Basic Research of China National Tobacco Corporation,Zhengzhou Tobacco Research Institute of China National Tobacco Corporation,Zhengzhou 450001)

机构地区：[1]河南大学河南省手性化学国际联合基地,开封475004 [2]河南师范大学化学化工学院,新乡453007 [3]中国烟草总公司郑州烟草研究院烟草香料基础研究重点实验室,郑州450001

出　　处：《有机化学》2022年第5期1396-1406,共11页Chinese Journal of Organic Chemistry

基　　金：国家自然科学基金(No.21925103);中国科协青年人才托举工程(No.2017QNRC001)资助项目.

摘　　要：喹喔啉-2(1H)-酮的生物学重要性激发了开发高效简便合成方法学的持续追求.其中,对其C3—H官能团化已成为近年的研究热点,尤其是利用光催化平台.目前除了光催化产生的自由基直接加成喹喔啉-2(1H)-酮,已有零星三组分串联反应策略被报道,这一手段是基于烯烃优先接受自由基加成,由所产生的自由基物种随后加成到喹喔啉-2(1H)-酮.鉴于多组分反应能够有效丰富该化合物类型,发展新的策略成为必然.报道了α-溴代芳基乙酮与喹喔啉-2(1H)-酮的光氧化还原催化反应,用于构建重要的1,4-二酮官能团化衍生物.这是一个新的串联反应策略:自由基首先加成到喹喔啉-2(1H)-酮,所产生的中间体进一步接受溴代物产生的自由基加成或与溴代物发生SN2反应.The biological importance of quinoxalin-2(1H)-ones has inspired increasing pursuit for the development of efficient and expedient synthetic methods to access these entities.Among them,C3—H functionalization of quinoxalin-2(1H)-ones has been a sought-after strategy in recent years,especially using photocatalysis platform to trigger radical intermediates.Besides the direct addition of photocatalysis-yielding radicals to 3-position of quinoxalin-2(1H)-ones,a handful of threecomponent cascade reactions have been described,wherein olefins were used to preferentially accept radicals to generate new radical intermediates to experience the second addition process.Given the robust ability of cascade strategy to enrich the varieties of quinoxalin-2(1H)-ones,the exploration of new protocols remains a highly attractive task.Herein,we report photoredox catalytic reactions of quinoxalin-2(1H)-ones with 2-bromo-1-arylethan-1-ones as the partners,leading to a series of valuable 1,4-diketone-functionalized quinoxalin-2(1H)-one derivatives with satisfactory results.This is an unprecedented cascade reaction strategy,involving radical addition to quinoxalin-2(1H)-ones and the resultant intermediates to accept a second addition of radicals generated from bromide substrates or to experience SN2 reaction with bromides.

关 键 词：可见光 光氧化还原催化 自由基加成 串联反应 2-羟基喹喔啉 

分 类 号：O626[理学—有机化学]