Visible-light-mediated photoredox minisci C–H alkylation with alkyl boronic acids using molecular oxygen as an oxidant
作者:Jianyang Dong、Fuyang Yue、Hongjian Song、Yuxiu Liu、Qingmin Wang
DOI:10.1039/d0cc05946c
日期:——
report a protocol for direct visible-light-mediated Minisci C–H alkylation reactions of heteroarenes with alkyl boronic acids using molecular oxygen as the sole oxidant. This mild protocol uses an inexpensive, green oxidant; permits efficient functionalization of various N-heteroarenes with a broad range of primary and secondaryalkyl boronic acids; and is scalable to the gram level. We demonstrated the
Transition-metal-free alkylation strategy: facile access to alkylated oxindoles <i>via</i> alkyl transfer
作者:Wen-Qin Yu、Jian-Hong Fan、Pu Chen、Bi-Quan Xiong、Jun Xie、Ke-Wen Tang、Yu Liu
DOI:10.1039/d2ob00019a
日期:——
The transition-metal-free alkylation/cyclization of activated alkenes using Hantzschesterderivatives as effective alkyl reagents is described. A wide variety of valuable oxindoles was constructed in a single step with excellent selectivity. The reaction occurs through the formation of alkyl radical species followed by the tandem addition/annulation of olefins under oxidative conditions. This protocol
Oxidant-Assisted Sulfonylation/Cyclization Cascade Synthesis of Alkylsulfonylated Oxindoles via the Insertion of SO2
作者:Long-Jin Zhong、Hui Chen、Xuan Shang、Bi-Quan Xiong、Ke-Wen Tang、Yu Liu
DOI:10.1021/acs.joc.3c02860
日期:2024.4.19
An oxidant-assisted tandem sulfonylation/cyclization of electron-deficient alkenes with 4-alkyl-substituted Hantzsch esters and Na2S2O5 for the preparation of 3-alkylsulfonylated oxindoles under mild conditions in the absence of a photocatalyst and transition metal catalyst is established. The mechanism studies show that the alkyl radicals, which come from the cleavage of the C–C bond in 4-substituted
缺电子烯烃与4-烷基取代的Hantzsch酯和Na 2 S 2 O 5的氧化剂辅助串联磺酰化/环化反应,在温和条件下,在没有光催化剂和过渡金属催化剂的情况下制备3-烷基磺酰化羟吲哚的方法是已确立的。机理研究表明,在氧化剂条件下,4-取代Hantzsch酯中C-C键断裂产生的烷基自由基,随后经历二氧化硫的原位插入,生成关键的烷基磺酰自由基中间体。这种三组分反应为构建烷基磺酰化羟吲哚提供了有效且简便的路线,并避免使用剧毒的烷基磺酰氯或烷基磺酰肼作为烷基磺酰基源。
Metal-free synthesis of 5-alkylated dihydrobenzimidazo[2,1-a]isoquinolines from pendent unactivated alkenes via double C–H functionalizations
作者:Mai Zhang、Xiao-Jing Tian、Yi-Han Gao、Ying Wen、Ting Xiao、Zhao-Yuan Yu、Jiang-Sheng Li、Zhi-Wei Li、Wei-Dong Liu