在1-(邻乙炔基芳基)脲的金(I)催化的杂环化反应中揭示了π和双σ,π-金激活模式之间的竞争。描述了金络合物中各种配体对这些活化方式的选择的显着影响。阳离子[Au(IPr)] +(IPr = 2,6-双(二异丙基苯基)咪唑-2-2-亚烷基)络合物可干净地促进末端炔烃的π活化,而[Au(P t Bu 3)] +有利于中间σ ,π种。
在1-(邻乙炔基芳基)脲的金(I)催化的杂环化反应中揭示了π和双σ,π-金激活模式之间的竞争。描述了金络合物中各种配体对这些活化方式的选择的显着影响。阳离子[Au(IPr)] +(IPr = 2,6-双(二异丙基苯基)咪唑-2-2-亚烷基)络合物可干净地促进末端炔烃的π活化,而[Au(P t Bu 3)] +有利于中间σ ,π种。
Gold(I)-Catalyzed Reactions of 1-(<i>ortho</i>-Alkynylaryl)ureas: Highly Selective Heterocyclization and Synthesis of Mixed<i>N</i>,<i>O</i>-Acetals
作者:Ana Gimeno、Ana B. Cuenca、Mercedes Medio-Simón、Gregorio Asensio
DOI:10.1002/adsc.201300730
日期:2014.1.13
The open chain amino O,O‐acetals and a series of new cyclic mixed N,O‐acetals containing the trifluoroethyl group were synthesized when the reactions were performed in ethanol or trifluoroethanol, respectively, as solvent. The procedure allows for an easy access to this versatile class of key intermediates in organic synthesis from simple startingmaterials. The effect of using either DMF or protic
NHC-Stabilized Gold(I) Complexes: Suitable Catalysts for 6-<i>exo</i>-dig Heterocyclization of 1-(<i>o</i>-Ethynylaryl)ureas
作者:Ana Gimeno、Mercedes Medio-Simón、Carmen Ramírez de Arellano、Gregorio Asensio、Ana B. Cuenca
DOI:10.1021/ol100595s
日期:2010.5.7
3-substituted 1-(o-ethynylaryl)ureas 1 selectively undergo either 6-exo-dig or 5-endo-dig cyclization (to give 4-methylene-3,4-quinazolin-2-ones 2 or indoles 3, respectively) depending on the choice of the metal, ligand, and reaction conditions. The best results (up to 96% yield) in the preparation of the hydroamination products 2 are achieved with the highly bulky NHC-stabilized cationic gold(I) complex
Well-Defined Dinuclear Gold Complexes for Preorganization-Induced Selective Dual Gold Catalysis
作者:Vincent Vreeken、Daniël L. J. Broere、Anne C. H. Jans、Marianne Lankelma、Joost N. H. Reek、Maxime A. Siegler、Jarl Ivar van der Vlugt
DOI:10.1002/anie.201603938
日期:2016.8.16
well‐defined dinuclear goldcomplexes as precursors for dual gold catalysis are explored. Using the preorganizing abilities of the ditopic PNHPiPr (LH) ligand, dinuclear AuI–AuI complex 1 and mixed‐valent AuI–AuIII complex 2 provide access to structurally characterized chlorido‐bridged cationic species 3 and 4 upon halide abstraction. For 2, this transformation involves unprecedented two‐electron oxidation of
Competitive Gold-Activation Modes in Terminal Alkynes: An Experimental and Mechanistic Study
作者:Ana Gimeno、Ana B. Cuenca、Samuel Suárez-Pantiga、Carmen Ramírez de Arellano、Mercedes Medio-Simón、Gregorio Asensio
DOI:10.1002/chem.201304087
日期:2014.1.13
between π‐ and dual σ,π‐gold‐activation modes is revealed in the gold(I)‐catalyzed heterocyclization of 1‐(o‐ethynylaryl)urea. A noticeable effect of various ligands in gold complexes on the choice of these activation modes is described. The cationic [Au(IPr)]+ (IPr=2,6‐bis(diisopropylphenyl)imidazol‐2‐ylidene) complex cleanly promotes the π activation of terminalalkynes, whereas [Au(PtBu3)]+ favors intermediate
在1-(邻乙炔基芳基)脲的金(I)催化的杂环化反应中揭示了π和双σ,π-金激活模式之间的竞争。描述了金络合物中各种配体对这些活化方式的选择的显着影响。阳离子[Au(IPr)] +(IPr = 2,6-双(二异丙基苯基)咪唑-2-2-亚烷基)络合物可干净地促进末端炔烃的π活化,而[Au(P t Bu 3)] +有利于中间σ ,π种。