Development of Dynamic Multi-Functional Chiral Molecular Catalysts for Asymmetric Reduction and C-C Bond Formation

具有M/NH双功能单元的手性过渡金属酰胺络合物Ru(TsdPEN)η^6-芳烃或C_p^*M(TsdPEN)，(M=Rh，Ir)，具有足够的Bronsted碱度来去质子化2-丙醇或甲酸和酸性有机化合物，分别得到氢胺络合物和带有金属键合的C-亲核亲核剂的胺络合物。由于酰胺络合物和胺络合物之间快速有效的相互转化，手性酰胺络合物已被证明以高度立体选择性的方式实现了α取代芳香酮的不对称转移氢化和环烯的不对称Michael加成。动态M/NH双功能效应可应用于由Ru_3(CO)_(12)和手性二亚氨基二膦四齿配体原位生成的手性Ru簇基催化剂体系。该手性簇催化芳香酮在异丙醇中的不对称转移氢化反应，生成具有高ee的光学活性醇类。动态多…酰胺和胺类化合物具有更多的I-官能团效应，是催化剂具有高活性、高选择性和高实用性的原因。超临界流体是分子催化和特定流体利用的良好反应介质，SCCO_2使分子催化剂的反应活性和选择性得到显著提高。为了更深入地了解分子催化在这一特殊介质中的反应机理，利用配备高压氧化锆池的商用核磁共振波谱仪，发展了一种超临界流体核磁共振波谱方法。结果表明，三烷基亚磷酸盐配体能有效地提高二氯钯(II)和二氯铀络合物在SCCO_2中的溶解度，而Ru络合物促进苯乙炔、二乙胺和SCCO_2快速生成氨基甲酸乙烯酯。二乙胺在SCCO_2中的动态行为的核磁共振研究表明，N，N-二乙基氨基甲酸的生成是可逆的，氨基甲酸的浓度受压力和温度的影响很大。较少

A well-defined chiral transition metal amide complex with a M/NH bifunctional unit, Ru(Tsdpen)η^6-arene) or C_p^*M(Tsdpen), (M = Rh, Ir), has sufficient Bronsted basicity to deprotonate 2-propanol or formic acid and acidic organic compounds, leading to a hydrido amine complex and amine complexes bearing a metal bonded C- nucleophile, respectively. Thanks to a rapid and effective interconversion between the amide complex and the amine complex, the chiral amide complex has proven to effect asymmetric transfer hydrogenation of α-substituted aromatic ketones and asymmetric Michael addition to cyclic eneones in a highly stereoselctive manner. The dynamic M/NH bifunctional effect can be applied to the chiral Ru cluster-based catalyst systems generated in situ from Ru_3(CO)_<12> and chiral diiminodiphosphine tetradentate ligands. This chiral cluster effected asymmetric transfer hydrogenation of aromatic ketones in 2-propanol, leading to optically active alcohols with high ee. The dynamic mult … More i-functional effect of both the amide and the amine complexes is responsible for the excellent catalyst performance in terms of high reactivity, selectivity, and practicability.We have demonstrated that supercritical fluids are promising reaction media for molecular catalysis and the utilization of a particular fluid, scCO_2 caused a remarkable enhancement of reactivities and selectivities of molecular catalysts. In order to gain deeper understanding of the reaction mechanism of the molecular catalysis in this unique media, a supercritical fluid nuclear magnetic resonance (scNMR) spectroscopic method has been developed using a commercially available NMR spectrometer equipped with a high-pressure zirconia cell. We found that trialkylphosphite ligands are highly effective for increasing the solubility of dichloropalladium(II) and dichlororuthenium(II) complexes in scCO_2 and the Ru complex promoted rapid vinyl carbamate formation from phenylacetylene, diethylamine, and scCO_2. The scNMR investigation on a dynamic behavior of diethylamine in scCO_2 revealed that formation of N, N-diethylcarbamic acid was reversible and the concentration of the carbamic acid was highly influenced by the pressure and temperature. Less