Asymmetric Synthesis of α-Keto Esters via Cu(II)-Catalyzed Aerobic Deacylation of Acetoacetate Alkylation Products: An Unusually Simple Synthetic Equivalent to the Glyoxylate Anion Synthon
作者:Kimberly M. Steward、Jeffrey S. Johnson
DOI:10.1021/ol200649u
日期:2011.5.6
alpha-keto esters is described using a copper(II)-catalyzed aerobic deacylation of substituted acetoacetate esters. The substrates for the title process arise from catalytic, enantioselectiveconjugateadditions and alkylation reactions of acetoacetate esters. The mild conditions do not induce racemization of the incipient enolizable alpha-keto ester. The reaction is tolerant of esters, certain ketones
Enantioselective Michael Reaction Catalyzed by Well-Defined Chiral Ru Amido Complexes: Isolation and Characterization of the Catalyst Intermediate, Ru Malonato Complex Having a Metal−Carbon Bond
Chiral Ru amido complexes promote asymmetric Michael addition of malonates to cyclic enones, leading to Michael adducts with excellent ee's, in which the chiral Ru amido complexes react with malonates to give isolable catalyst intermediates, chiral Ru malonato complexes bearing a metal bound C-nucleophile.
Well-defined 16-electron chiral Ru amido complexes, Ru[(R,R)-diamine](η6-arene), efficiently catalyze asymmetric Michael additions of Michael donors to cyclicenones to give adducts in high yields and with excellent ee’s. β-Ketoesters or nitroacetate as Michael donors react with 2-cyclopentenone in toluene or t-butyl alcohol containing the Ru amido catalyst (S/C=50) to afford the Michael adduct in
明确定义的16电子手性钌酰氨络合物,钌[([R ,- [R )-二胺](η 6 -arene),有效地催化迈克尔供体,以环状烯酮的非对称Michael加成,得到的加合物以高产率和具有优良的EE的。作为迈克尔供体的β-酮酸酯或硝基乙酸酯与2-环戊烯酮在含有钌酰胺催化剂(S / C = 50)的甲苯或叔丁醇中反应,以99%的收率和高达92%的ee提供迈克尔加合物。反应的结果受到二胺和芳烃配体的结构以及反应条件的微妙影响。
Mechanism of Enantioselective C−C Bond Formation with Bifunctional Chiral Ru Catalysts: NMR and DFT Study
作者:Ilya D. Gridnev、Masahito Watanabe、Hui Wang、Takao Ikariya
DOI:10.1021/ja107597w
日期:2010.11.24
The mechanism of Michael addition reactions of 1,3-dicarbonyl compounds to cyclic enones catalyzed by bifunctional Ru catalysts bearing N-sulfonylated (R,R)-DPEN ligands (DPEN = (R,R)-1,2-diphenylethylenediamine) was studied by NMR and DFT computational analyses. NMR investigation of the stoichiometric reactions of chiral amido Ru complexes, Ru(N-sulfonylated dpen)(η(6)-arene) 1a-c, with dimethyl malonate
研究了带有N-磺酰化(R,R)-DPEN配体(DPEN = (R,R)-1,2-二苯基乙二胺)的双功能Ru催化剂催化1,3-二羰基化合物与环烯酮的迈克尔加成反应机理通过 NMR 和 DFT 计算分析。手性酰氨基 Ru 配合物 Ru(N-磺酰化 dpen)(η(6)-芳烃) 1a-c 与丙二酸二甲酯 2 和 β-酮酯 3 的化学计量反应的 NMR 研究表明,在降低的温度下,去质子化在以立体选择性的方式提供胺配合物。与丙二酸酯 2 的反应仅提供了 C 结合的氨基 Ru 复合物 6a,c,而 β-酮酯 3 的反应产生了快速相互转化的 C 和 O 结合的复合物的平衡混合物。通过单晶X射线分析确定了C-结合Ru配合物6c和O-结合Ru配合物9c的结构。一项计算研究表明,对映选择性 CC 键的形成是通过螯合离子对的中间形成进行的,这些离子对通过 Ru 金属中心协调烯酮分子,为 CC 键的形成创造了一个
Asymmetric 1,4-addition of β-keto esters to cyclic enones catalyzed by Ru amido complexes
作者:Hui Wang、Masahito Watanabe、Takao Ikariya
DOI:10.1016/j.tetlet.2004.12.026
日期:2005.2
Well-defined Ru amido complexes effected asymmetric Michael addition of beta-keto esters to 2-cyclopenten-l-one to give quantitatively the corresponding Michael adducts with excellent ee although with a 1:1 diastereomer ratio. The stereochemical outcome of the reaction was significantly influenced by the structures of the catalysts and the structures of the P-keto esters; the ee value reaching up to 97%. (C) 2004 Elsevier Ltd. All rights reserved.