Cu II 2 (μ-η 2 :η 2 -过氧化) 和 Cu III 2 (μ-氧化) 2核代表铜/双氧化学中的关键中间体,它们对于双核介导的生物羟基化和氧化反应具有重要的机械作用。 III) 铜金属酶。虽然不同酶中活性物质的确切性质仍存在争议,但 Cu x /O 2物质之间平衡的转变越来越被认为是在这些中间体的不同反应模式之间切换的一种手段。在此,我们报告了一系列合成 Cu II 2 (μ-η 2 :η 2 -过氧化) 和 Cu III 2 (μ-氧化) 2二铜配合物与双(恶唑啉) (BOX)的全面光谱、晶体学和计算分析。封端配体。特别是,我们证明了 [Cu 2 O 2 ]核心的可逆过氧化物/双(μ-氧化物)相互转化可以通过配体主链上的外围(去)质子化事件触发。由于酶中的铜离子通常由组氨酸咪唑支持,组氨酸咪唑提供易于潜在(去)质子化的背面 N 原子,因此可以想象,[Cu 2 O 2 ] 物种之间的平衡会随着当地的
Design of boron bis-oxazolinate (B-BOXate) complexes: a new class of stable organometallic catalysts
作者:Marco Bandini、Pier Giorgio Cozzi、Magda Monari、Rossana Perciaccante、Simona Selva、Achille Umani-Ronchi
DOI:10.1039/b103571c
日期:——
A new class of remarkably stable B-BOXate complexes has been
synthesised, isolated and employed as chiral catalysts for asymmetric
reduction of variously substituted prochiral ketones.
ChiralC2-Boron-Bis(oxazolines) in Asymmetric Catalysis – A Theoretical Study of the Catalyzed Enantioselective Reduction of Ketones Promoted by Catecholborane
作者:Marco Bandini、Andrea Bottoni、Pier Giorgio Cozzi、Gian Pietro Miscione、Magda Monari、Rossana Pierciaccante、Achille Umani-Ronchi
DOI:10.1002/ejoc.200600133
日期:2006.10
computational results have provided a complete mechanistic picture, which explains the stereochemicaloutcome of the reaction. The B–BOXate complex binds both the reducing agent CATBH and the carbonylcompound, activating the former as a hydride donor and enhancing the electrophilicity of the latter. Moreover, the structure of two boron–BOX (BOXate) complexes has been confirmed by means of X-ray diffraction
Hexaalkylguanidinium salts as ionic liquids – applications in titanium and aluminium alcoholate assisted synthesis
作者:Maria Arkhipova、Svetlana Eichel、Gerhard Maas
DOI:10.1039/c4ra09567g
日期:——
hexaalkylguanidinium-based roomtemperature ionic liquids was screened. The solvent/solute combinations which displayed the highest alcoholate solubility and stability were applied as Lewis-acidic catalytic media for several dehydrating cyclocondensations: lactamisation of ω-aminocarboxylic acids, directamidation of carboxylicacids, synthesis of oxazolines from carboxylicacids and 2-aminoethanol, lactonisation
bioinorganic model studies. Here, it is shown that simple bis(oxazoline)s (BOXs), which are classified among the so-called “privileged ligands”, provide a suitable scaffold for supporting such biomimetic copper/dioxygen chemistry. Three derivatives R,HBOX-Me2 (R = H, Me, tBu) with different backbone substituents have been used. Their bis(oxazoline)-copper(I) complexes bind dioxygen to yield biomimetic