Construction of All-Carbon Quaternary Centers through Cu-Catalyzed Sequential Carbene Migratory Insertion and Nucleophilic Substitution/Michael Addition
作者:Chengpeng Wang、Fei Ye、Chenggui Wu、Yan Zhang、Jianbo Wang
DOI:10.1021/acs.joc.5b01592
日期:2015.9.4
cross-coupling reaction of terminal alkyne, α-diazo ester, and alkyl halide has been developed. This transformation involves sequent migratory insertion of copper-carbene and nucleophilic substitution, in which a C(sp)–C(sp3) bond and a C(sp3)–C(sp3) bond are formed successively on a carbenic center. Michael addition acceptors can also be employed instead of alkyl halides that enable Michael addition to
Straightforward Synthesis of Allylated Keto Esters: The Palladium-Catalysed Haloketone Alkoxycarbonylation/ Allylation Domino Reaction
作者:Benoit Wahl、Steven Giboulot、André Mortreux、Yves Castanet、Mathieu Sauthier、Frédéric Liron、Giovanni Poli
DOI:10.1002/adsc.201100848
日期:2012.4.16
The palladium‐catalysed α‐chloro ketone methoxycarbonylation and allylic alkylation reactions can be efficiently combined to provide a new catalytic domino reaction. The first, carbonylative, step generates the β‐keto ester, which acts as the nucleophile in a subsequent allylation step. The use of allyl phenates in combination with Xantphos ligand are the key features allowing one to obtain the allylated
Monoallylation and monoalkylation of diketones and β-keto esters with allylic and benzylic alcohols catalysed by [Cp*Co(CH3CN)3][SbF6]2 (I) are reported. The method does not require any additive and affords regioselective products. The mechanistic investigations were done by in situ 1H NMR spectroscopy as well as control experiments. It has been shown that reactions proceed via η3-allyl complex formation or
报道了[Cp*Co(CH 3 CN) 3 ][SbF 6 ] 2 ( I )催化的二酮和β-酮酯与烯丙醇和苄醇的单烯丙基化和单烷基化。该方法不需要任何添加剂并提供区域选择性产物。通过原位1 H NMR 光谱以及对照实验进行了机理研究。已表明反应通过形成 η 3 -烯丙基络合物或烯丙基醚中间体进行。烷基化仅通过醚中间体发生。所得烯丙基化和烷基化产物已用于合成十一种新的三取代吡唑和一种吡唑啉酮。
Regiocontrol in palladium-catalysed allylic alkylation by addition of lithium iodide
作者:Motoi Kawatsura、Yasuhiro Uozumi、Tamio Hayashi
DOI:10.1039/a707652e
日期:——
Regioselectivity in the palladium-catalysed allylic alkylation of 1-arylprop-2-enyl acetates [ArCH(OAc)CHCH2] or (E)-3-phenylprop-2-enyl acetate (PhCHCHCH2OAc) with sodium enolates of soft carbon nucleophiles is controlled by addition of a catalytic amount of lithium iodide to give lienar products [(E)-ArCHCHCH2Nu] exclusively; their branch isomers [ArCH(Nu)CHCH2] were not detected.
Oxidative reactions of α-allyl-β-keto esters 5 with Mn(OAc)3·2H2O give the δ-hydroxy-β-,γ-unsaturated-α-keto esters 6 in good yields. The mechanism of this reaction is discussed.