Sustainable Cascades to Difluoroalkylated Polycyclic Imidazoles
作者:Sheng‐Nan Lin、Yu Chen、Xiao‐Dong Luo、Yi Li
DOI:10.1002/ejoc.202100868
日期:2021.8.20
synthesis of imidazoles from alkenes is described here. Series of highly functionalized polycyclic imidazoles were prepared efficiently with 0.01 equiv. of fac-Ir(ppy)3 as photocatalyst under the irradiation of 3 W blue LEDs. This method is characterized by a wide substrate scope with up to 95 % isolated yield under mild conditions. Mechanistic studies indicated a photocatalyzed direct radical difluoroalkylated
The exo-selective C-H cycloaddition of imidazoles to 1,1-disubstitutedalkenes has been achieved for the first time by using half-sandwich scandium catalysts. A wide range of imidazole compounds bearing various 1,1-disubstituted aliphatic alkenes, styrenes, dienes and enynes have been selectively converted in high yields to the corresponding bicyclic imidazole derivatives bearing -all-carbon-substituted
Copper-Catalyzed Direct Cycloaddition of Imidazoles and Alkenes to Trifluoromethylated Tricyclic Imidazoles
作者:Shengnan Lin、Jianchao Cui、Yu Chen、Yi Li
DOI:10.1021/acs.joc.1c01832
日期:2021.11.5
We reported herein a copper-catalyzed trifluoromethylarylated cycloaddition of imidazoles and olefins using CF3SO2Cl as the radical source to synthesize highly functionalized tricyclic imidazoles. This procedure exhibits a wide range of substrate scope with 25%–93% isolated yields (36 examples). Mechanistic studies were carried out to support a free trifluoromethyl radical pathway.
我们在此报道了铜催化的咪唑和烯烃的三氟甲基芳基化环加成反应,使用 CF 3 SO 2 Cl 作为自由基源合成高度官能化的三环咪唑。该程序展示了广泛的底物范围,分离产量为 25%–93%(36 个示例)。进行了机理研究以支持游离三氟甲基自由基途径。
Cu‐Catalyzed C−H Perfluoroalkylation/Cyclization of Unactivated Alkenes: Synthesis of Perfluoroalkylated Tricyclimidazoles
A copper-catalyzed cascade difunctionalization of unactivated olefins with readily available Rf-I reagents to construct Csp3−CF2/C−C bonds has been reported. This strategy provides a convenient access to a variety of useful perfluoroalkylatedtricyclimidazole derivatives in reasonable yields. Preliminary mechanistic studies indicate that the present reaction probably undergo a radical/SET (single electron
已经报道了使用现成的 R f -I 试剂对未活化烯烃进行铜催化级联双官能化以构建 C sp 3 -CF 2 /C-C 键。该策略提供了一种以合理的收率方便地获得各种有用的全氟烷基化三环咪唑衍生物的途径。初步的机理研究表明,目前的反应可能经历自由基/SET(单电子转移)途径。该转化条件温和、操作简单、原子经济、底物适用范围广。
Catalyst-Controlled Nickel-Catalyzed Intramolecular <i>endo</i>-Selective C–H Cyclization of Benzimidazoles with Alkenes
作者:Zi-Jian Liu、Jiang-Fei Li、Feng-Ping Zhang、Xue-Tao Xu、Mengchun Ye
DOI:10.1021/acs.orglett.2c04012
日期:2023.1.20
Compared with the widely explored exo-selective C–H cyclization, transition metal-catalyzed endo-selective C–H cyclization of benzimidazoles with alkenes has been a formidable challenge. Previous efforts mainly rely on substrate-controlled methods, rendering the product complexity restricted. Herein we report a catalyst-controlled method to facilitate endo-cyclization, in which a bulky N-heterocyclic