Pd(II)-Catalyzed Enantioselective C–H Activation/C–O Bond Formation: Synthesis of Chiral Benzofuranones
摘要:
Pd(II)-catalyzed enantioselective C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded chiral benzofuranones. This reaction provides the first example of enantioselecctive C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.
Ligand-Accelerated Palladium(II)-Catalyzed Enantioselective Amination of C(sp<sup>2</sup>)–H Bonds
作者:Xiu-Fen Cheng、Fan Fei、Yan Li、Yi-Ming Hou、Xin Zhou、Xi-Sheng Wang
DOI:10.1021/acs.orglett.0c02216
日期:2020.8.21
The first example of the Pd(II)-catalyzed enantioselective amination of aryl C–H bonds is reported. The key to the successful realization of this asymmetric catalytic transformation was the identification of mono-N-protected α-amino-O-methylhydroxamic acid (MPAHA) ligands, which promote reactivity under mild conditions and control enantioselectivity. The counteranions in the solvent medium, hexafluoroacetylacetate
Pd(II)-Catalyzed Enantioselective C−H Olefination of Diphenylacetic Acids
作者:Bing-Feng Shi、Yang-Hui Zhang、Jonathan K. Lam、Dong-Hui Wang、Jin-Quan Yu
DOI:10.1021/ja909571z
日期:2010.1.20
Pd(II)-catalyzed enantioselective C-H olefination of diphenylaceticacid substrates has been achieved through the use of monoprotected chiral amino acid ligands. The absolute configuration of the resulting olefinated products is consistent with that of a proposed C-H insertion intermediate.
Electrochemical Decarboxylative Elimination of Carboxylic Acids to Alkenes
作者:Jiage Yu、Teng Liu、Wanhao Sun、Yunfei Zhang
DOI:10.1021/acs.orglett.3c02997
日期:2023.11.3
An electrochemical strategy for the decarboxylative elimination of carboxylic acids to alkenes at room temperature has been developed. This mild and oxidant-free method provides a green alternative to traditional thermal decarboxylation reactions. Structurally diverse aliphatic carboxylic acids, including biologically active drugs, underwent smooth conversion to the corresponding alkenes in good to
Pd(II)-catalyzed enantioselective C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded chiral benzofuranones. This reaction provides the first example of enantioselecctive C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.
stereocenters through cross-coupling reactions at distal positions of aryl substituents. The new class of amino acid-derived ionic chiral catalysts enables desymmetrizing (enantiotopic-group-selective) Suzuki–Miyaura reaction, Sonogashira reaction, and Buchwald–Hartwig amination between diverse diarylmethane scaffolds and aryl, alkynyl, and amino coupling partners, providing rapid access to enantioenriched
不对称催化的合成应用依赖于键构建的策略调整以产生目标分子的手性。远程去对称化提供了催化转化和立体元素生成的空间解耦的独特优势。然而,这种空间分离对于手性催化剂通过远离亲手性中心三个或更多键的反应来区分遥远的对映位点来说存在很大的困难。在这里,我们报告了一种通过芳基取代基远端位置的交叉偶联反应建立无环季碳立构中心的策略。新型氨基酸衍生的离子手性催化剂能够实现不同二芳基甲烷支架与芳基、炔基和氨基偶联伙伴之间的去对称(对映基团选择性)Suzuki-Miyaura反应、Sonogashira反应和Buchwald-Hartwig胺化,从而提供快速访问将取代基投射到三维空间中广泛分布的位置的对映体富集分子。实验和计算研究揭示了手性配体的 C 末端通过离子相互作用对底物进行静电转向。催化剂的酰胺基团和钾阳离子之间的协同离子偶极相互作用有助于预组织,从而将不对称性传递给产物。这项研究表明,通过设计离子催