Addition of 1,3-dicarbonyl compounds to terminal alkynes catalyzed by a cationic cobalt(<scp>iii</scp>) complex
作者:Mohan Chandra Sau、Manish Bhattacharjee
DOI:10.1039/d0ra05923d
日期:——
The Nakamura reaction using a cationic cobalt(III) complex, [Cp*Co(CH3CN)3][SbF6]2 as the catalyst under neutral and aerobic conditions at 110 °C has been described. In solution, the complex is expected to lose a hemilabile acetonitrile ligand to produce a highly electron-deficient cobalt(III) center, and the Lewis acidic nature of the cobalt center has been exploited for the enolization of the dicarbonyl
已经描述了使用阳离子钴( III ) 配合物[Cp*Co(CH 3 CN) 3 ][SbF 6 ] 2作为催化剂在中性和有氧条件下在110 °C 下的Nakamura 反应。在溶液中,该配合物预计会失去半可溶的乙腈配体,从而产生高度缺电子的钴(III) 中心,并且钴中心的路易斯酸性已被用于二羰基化合物的烯醇化。1,3-二羰基化合物与炔烃反应得到相应的烯基衍生物。然而,苯乙炔及其衍生物与 β-酮酯反应得到相应的三联苯化合物。已经基于原位LCMS 测量提出了反应机制的细节。
Indium-Catalyzed 2-Alkenylation of 1,3-Dicarbonyl Compounds with Unactivated Alkynes
the position of C-C bond formation on the acetylene moiety. In most of the cases, the reaction requires less than 1-mol % loading of the catalyst and does not require solvent. The reaction tolerates a wide variety of functional groups including ester, ether, allylic halide, furan, thiophene, and protected amine. Experimental and theoretical studies suggested that the reaction proceeds via a concerted
A ruthenium-catalyzed coupling of alkynes with 1,3-diketones
作者:Megan K. Pennington-Boggio、Brian L. Conley、Travis J. Williams
DOI:10.1016/j.jorganchem.2012.05.017
日期:2012.10
Ruthenium(III) chloride hydrate is a convenient catalyst for the addition of active methylene compounds to aryl alkynes. These reactions are rapid, operationally simple, and high yielding in cases. Most significantly, no precautions are required to exclude air or water from the reactions. All reagents are commercially available at reasonable prices, and the reactions can be conducted in disposable glassware with minimal solvent. (C) 2012 Elsevier B.V. All rights reserved.
Rhenium-Catalyzed Insertion of Terminal Acetylenes into a C−H Bond of Active Methylene Compounds
[GRAPHICS]A rhenium complex, [ReBr(CO)(3)(thf)](2), Catalyzed the intermolecular reactions of 1,3-dicarbonyl compounds with terminal acetylenes and gave the corresponding alkenyl derivatives in excellent yields. These reactions could apply to an intramolecular version and gave the corresponding cyclic compounds quantitatively.