A Three-Component Strategy for Benzoselenophene Synthesis under Metal-Free Conditions Using Selenium Powder
作者:Penghui Ni、Jing Tan、Wenqi Zhao、Huawen Huang、Fuhong Xiao、Guo-Jun Deng
DOI:10.1021/acs.orglett.9b00739
日期:2019.5.17
An efficient three-component benzoselenophenes formation has been developed from substituted indoles, acetophenones, and selenium powder under metal-free conditions. 2-Aryl indoles played an important role to promote benzoselenophene formation from acetophenone derivatives and selenium powder. One C–C and two C–Se bonds were selectively formed to provide 40 new benzoselenophenes in good yields.
TEMPO-Mediated Cross-Dehydrogenative Coupling of Indoles and Imidazo[1,2-<i>a</i>]pyridines with Fluorinated Alcohols
作者:Dhananjay S. Nipate、Sonam Jaspal、Vikki N. Shinde、Krishnan Rangan、Anil Kumar
DOI:10.1021/acs.orglett.1c00031
日期:2021.2.19
A simple and highly efficient metal-free method has been developed for hydroxyfluoroalkylation of indoles and imidazo[1,2-a]pyridines via TEMPO-mediated C(sp3)–H and C(sp2)–H bond cross-dehydrogenative coupling of fluorinated alcohols and indoles. The protocol showed broad substrate scope, afforded good yields of hydroxyfluoroalkylated products, and was amenable for scale-up. Mechanistic investigation
已经开发了一种简单高效的无金属方法,用于通过TEMPO介导的C(sp 3)–H和C(sp 2)–H键交叉脱氢偶联将吲哚和咪唑并[1,2- a ]吡啶进行羟基氟烷基化氟化醇和吲哚。该方案显示出广泛的底物范围,提供了良好的羟基氟烷基化产物收率,并且适合规模扩大。机理研究表明该自由基途径的参与。
Internal Oxidant-Triggered Aerobic Oxygenation and Cyclization of Indoles under Copper Catalysis
作者:Huawen Huang、Jinhui Cai、Xiaochen Ji、Fuhong Xiao、Ya Chen、Guo-Jun Deng
DOI:10.1002/anie.201508076
日期:2016.1.4
A concise synthesis of pyrazolo[1,5‐a]indole derivatives by copper‐catalyzed aerobic oxygenation and cyclization of indoles with oxime acetates is described. This protocol represents an elegant example of N‐1, C‐2, and C‐3 tri‐functionalization of indoles in one‐pot. Mechanistic studies indicate the reaction proceeds through a radical procedure. Oximes as an internal oxidant have been demonstrated
The reaction of N-heteroaromatic compounds, such as 2-aryl-pyrrole, benzimidazole, imidazole, indole, and pyrazole derivatives, with alkynes in the presence of a catalytic amount of a nickel complex results in C–H/N–H oxidative annulation. The reaction shows a high functional group compatibility. While both Ni(0) and Ni(II) complexes show a high catalytic activity, Ni(0) is proposed as a key catalytic
N-杂芳族化合物(例如 2-芳基吡咯、苯并咪唑、咪唑、吲哚和吡唑衍生物)与炔烃在催化量的镍配合物存在下发生反应,导致 C-H/N-H 氧化成环。该反应表现出较高的官能团相容性。虽然Ni(0)和Ni( II )配合物均表现出高催化活性,但Ni(0)被认为是主催化循环中的关键催化物种。在 Ni( II ) 体系的情况下,反应的进行需要催化量的强碱(例如 KOBu t )的存在。与此形成鲜明对比的是,Ni(0) 系统不需要碱。所提出的机制得到了 DFT 研究的支持。
Pd-catalyzed C–H bond activation of Indoles for Suzuki reaction
作者:Isita Banerjee、Keshab Ch Ghosh、Surajit Sinha
DOI:10.1007/s12039-019-1649-y
日期:2019.8
practical method for Suzuki coupling by which unprotected or N-protected indoles may be selectively arylated in the C2-position through direct C–H bond activation by electrophilic \(\hbox Pd(TFA)}_2}\) catalyst. The protocol is operationally simple as it is carried out in dioxane/water mixture, and air as the sole oxidant at room temperature. Various 2-arylated indoles were obtained in good yields