BI-OAc-Accelerated C3–H Alkylation of Quinoxalin-2(1<i>H</i>)-ones under Visible-Light Irradiation
作者:Xiang-Kui He、Juan Lu、Ai-Jun Zhang、Qing-Qing Zhang、Guo-Yong Xu、Jun Xuan
DOI:10.1021/acs.orglett.0c02080
日期:2020.8.7
photoredox-catalyst-free radical alkylation of quinoxalin-2(1H)-ones has been described. This reaction utilizes 4-alkyl-1,4-dihydropyridines (R-DHPs) as alkyl radicalprecursors and acetoxybenziodoxole (BI-OAc) as an electron acceptor to undergo single-electron transfer with photoexcited R-DHPs. The benign conditions allow for good compatibility in the scope of both quinoxalin-2(1H)-ones and R-DHPs. The
A direct C–H alkylation of quinoxalinones at the C‐3 position with sodiumalkylsulfinates and phenyliodine(III) dicarboxylates has been developed under catalyst‐free conditions. A series of 3‐alkylquinoxalinones were afforded in moderate to excellent yields in this protocol, which offers a practical and efficient access to biologically interesting 3‐alkylquinoxalin‐2(1H)‐one derivatives.
DTBP-promoted decarbonylative alkylation of quinoxaline-2(1H)-ones with aldehydes
作者:Bingqing Wang、Hua Yao、Xiaoyang Zhong、Zhaohua Yan、Sen Lin
DOI:10.1016/j.tetlet.2020.152720
日期:2021.2
An efficient DTBP-promoted directalkylation of quinoxaline-2(1H)-ones with aldehydes has been developed under metal-free conditions. The reaction undergoes sequential decarbonylation and radical addition using aliphatic aldehyde as a cheap and abundant alkyl radical source. A convenient and efficient approach for the synthesis of various 3-alkylquinoxaline-2(1H)-ones was provided.
commercially available and cheap carboxylicacids as alkylating reagents, a practical methodology for the visible-light induced decarboxylative alkylation of quinoxalin-2(1H)-ones was developed. The reaction proceeds in the absence of metal-catalyst, acid or basic additive, or external photosensitizer, making it an environmentally friendly and attractive protocol for the alkylation of quinoxalines.
使用市售廉价的羧酸作为烷基化试剂,开发了一种实用的方法,用于可见光诱导的 quinoxalin-2(1 H )-ones 的脱羧烷基化。该反应在没有金属催化剂、酸或碱添加剂或外部光敏剂的情况下进行,使其成为一种环境友好且有吸引力的喹喔啉烷基化方案。
Electro-oxidative C–H alkylation of quinoxalin-2(1<i>H</i>)-ones with organoboron compounds
作者:Kaikai Niu、Yanke Hao、Lingyun Song、Yuxiu Liu、Qingmin Wang
DOI:10.1039/d0gc03892j
日期:——
Radical cleavage of C–B bonds to accomplish C–H functionalization is synthetically appealing but practically challenging. We report herein a mild electro-oxidative method for efficient C–H alkylation of quinoxalin-2(1H)-ones by means of radical addition reactions of alkyl boronic acids and esters and alkyl trifluoroborates to afford C–C coupled products.