site‐selective C3‐arylation of N‐methyl‐2‐oxindole with arylboronic acids at room temperature in aqueous media to yield a series of 3‐aryl‐N‐methyl‐2‐oxindoles. This catalytic reaction progressed well with a low catalyst loading (0.01 mol %) under open‐flask conditions. Notably, a column‐chromatography‐free method for the quantitative preparation of C3‐arylated N‐methyl‐2‐oxindoles is reported. The catalyst
两种新型Pd II ONO钳形络合物可有效地用作均相催化剂,用于在室温下在水性介质中将N-甲基-2-氧吲哚与芳基硼酸进行定点C3芳基化,生成一系列3-芳基-N-甲基-2-氧吲哚 在开瓶条件下,该催化剂的催化反应进展顺利,催化剂负载量低(0.01 mol%)。值得注意的是,据报道,采用了无柱色谱法定量制备C3芳基化的N-甲基-2-氧吲哚。该催化剂与多种底物表现出良好的相容性,并在多达五个连续运行中具有可回收性,而没有明显的收率损失。
Palladium(II) Complexes Bearing a Mixed Set of aNHC/Py/PR3/I2 Ligands: Applications in α-Arylation of Amide and Suzuki-Miyaura Coupling Reactions
been tested as potent precatalysts for α-arylation of oxindole and Suzuki-Miyaura cross couplingreactions. Different donor ligands such as pyridine, 3-chloropyridine, 4-methoxypyridine, PPh3 and PCy3 have been used to compare the catalytic activities. The PdII complexes containing mixed aNHC/PR3/I2 donor set appeared to be more active catalysts when compared with the complexes bearing mixed aNHC/Py/I2
具有异常或介离子卡宾络合物(一个NHC或MIC)配体在有机金属化学由于它们的各种催化应用找到广泛适用性。载有混合的NHC/Py/PR 3 /I 2 (R = Ph, Cy) 供体组的钯 (II) 配合物以联苯衍生的三唑鎓盐为起始原料。该配合物已通过核磁共振光谱和 ESI 质谱进行表征。两种配合物也已通过单晶 XRD 进行结构表征。Pd II配合物已被测试为有效的预催化剂,用于 oxindole 的 α-芳基化和 Suzuki-Miyaura 交叉偶联反应。不同的供体配体,如吡啶、3-氯吡啶、4-甲氧基吡啶、PPh3和 PCy 3已用于比较催化活性。将Pd II包含混合络合物一个NHC / PR 3 / I 2供体组出现时与所述配合物混合轴承相比更具活性的催化剂一NHC / PY / I 2供体在两个催化转换集。
Palladium-Catalyzed Chemoselective Activation of sp<sup>3</sup> vs sp<sup>2</sup> C–H Bonds: Oxidative Coupling To Form Quaternary Centers
作者:Gang Hong、Pradip D. Nahide、Uday Kumar Neelam、Peter Amadeo、Arjun Vijeta、John M. Curto、Charles E. Hendrick、Kelsey F. VanGelder、Marisa C. Kozlowski
DOI:10.1021/acscatal.9b00091
日期:2019.4.5
activation of alkyl C–H bonds vs arene C–H bonds with Pd(OAc)2 has been found to be generalizable to a number of nucleophilic substrates, allowing the formation of a range of hindered quaternary centers. The substrates share a common mechanistic path wherein Pd(II) initiates an oxidative dimerization. The resultant dimer modifies the palladium catalyst to favor activation of alkyl C–H bonds, in contrast to
作者:Gino Occhialini、Vignesh Palani、Alison E. Wendlandt
DOI:10.1021/jacs.1c12043
日期:2022.1.12
The positional isomerization of C═C double bonds is a powerful strategy for the interconversion of alkene regioisomers. However, existing methods provide access to thermodynamically more stable isomers from less stable starting materials. Here, we report the discovery of a dual catalyst system that promotes contra-thermodynamic positional alkeneisomerization under photochemical irradiation, providing
BF<sub>3</sub>·OEt<sub>2</sub> catalyzed decarbonylative arylation/C–H functionalization of diazoamides with arylaldehydes: synthesis of substituted 3-aryloxindoles
作者:Sengodagounder Muthusamy、Ammasi Prabu
DOI:10.1039/d2ob00003b
日期:——
A metal-free BF3·OEt2 catalyzed direct decarbonylative arylation of diazoamides with readily accessible aryl aldehydesunder an open-air atmosphere was developed to afford 3-aryloxindoles via 1,2-aryl migration with high selectivity. The reaction offers an efficient pathway for 3-arylation of diazoamides under relatively mildconditions, which shows a high level of functional group tolerance of both