Sequential Protocol for C(sp3)–H Carboxylation with CO2: Transition-Metal-Catalyzed Benzylic C–H Silylation and Fluoride-Mediated Carboxylation
摘要:
One of the most challenging transformations in current organic chemistry is the catalytic carboxylation of a C(sp(3))-H bond using CO2 gas, an inexpensive and ubiquitous Cl source. A sequential protocol for C(sp(3))-H carboxylation by employing a nitrogen-directed, metal-assisted, C-H activation/catalytic silylation reaction in conjunction with fluoride-mediated carboxylation with CO2 was established. The carboxylation proceeded only at the benzylic C(sp(3))-Si bond, not at the aromatic C(sp(2))-Si, which is advantageous for further manipulations of the products.
Nonbifunctional Outer-Sphere Strategy Achieved Highly Active α-Alkylation of Ketones with Alcohols by <i>N</i>-Heterocyclic Carbene Manganese (NHC-Mn)
作者:Xiao-Bing Lan、Zongren Ye、Ming Huang、Jiahao Liu、Yan Liu、Zhuofeng Ke
DOI:10.1021/acs.orglett.9b03030
日期:2019.10.4
nonbifunctional outer-sphere strategy was successfully utilized in developing an easily accessible N-heterocyclic carbene manganese (NHC-Mn) system for highly active α-alkylation of ketones with alcohols. This system was efficient for a wide range of ketones and alcohols under mild reaction conditions, and also for the green synthesis of quinoline derivatives. The direct outer-sphere mechanism and the high activity
Palladium-Catalyzed Methylation of Aryl C−H Bond by Using Peroxides
作者:Yuhua Zhang、Jianqing Feng、Chao-Jun Li
DOI:10.1021/ja0775063
日期:2008.3.1
A novel Pd(OAc)2-catalyzed methylation reaction by dicumylperoxide via aryl C−H bond activation was discovered. Various 2-phenylpyridine and acetanilides can be used as reactants in these reactions. Peroxide was used as both the methylatingreagent and the hydrogenacceptor.
Delineating the Role of Substituents on the Coordination Behavior of Aroylhydrazone Ligands in Pd
<sup>II</sup>
Complexes and their Influence on Suzuki–Miyaura Coupling in Aqueous Media
piperonal aroylhydrazone ligands (HL1–HL4) with [PdCl2(PPh3)2] in CH3OH and CHCl3 afforded four new Pd(II) complexes (1–4) featuring diverse coordination behaviors. These complexes 1–4 were fully characterized by elemental analyses, UV/Visible, FT‐IR and 1H/13C NMR spectra. The variant coordination modes of piperonal aroylhydrazone ligands with Pd(II) ion in these complexes were unambiguously confirmed
Sequential Protocol for C(sp<sup>3</sup>)–H Carboxylation with CO<sub>2</sub>: Transition-Metal-Catalyzed Benzylic C–H Silylation and Fluoride-Mediated Carboxylation
作者:Tsuyoshi Mita、Kenichi Michigami、Yoshihiro Sato
DOI:10.1021/ol301431d
日期:2012.7.6
One of the most challenging transformations in current organic chemistry is the catalytic carboxylation of a C(sp(3))-H bond using CO2 gas, an inexpensive and ubiquitous Cl source. A sequential protocol for C(sp(3))-H carboxylation by employing a nitrogen-directed, metal-assisted, C-H activation/catalytic silylation reaction in conjunction with fluoride-mediated carboxylation with CO2 was established. The carboxylation proceeded only at the benzylic C(sp(3))-Si bond, not at the aromatic C(sp(2))-Si, which is advantageous for further manipulations of the products.