Simulation of Selective Chemical Reactions and Theoretical Elucidation of their Mechanisms.

选择性化学反应的模拟及其机理的理论阐明。

• 批准号: 09650901
• 负责人: KOGA Nobuaki
• 金额: $ 1.34万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650901/
• 关键词: MO-then-MM method; IMOMM method; selective reactions; transition metal complex catalyst; asymmetric catalyst; 不斉触媒; プロピレン重合; Sm錯体触媒; B3LYP法; MM3法

In order to analyze the mechanism of selective reactions catalyzed by transition metal complexes and obtain useful information on devising catalysts, we have performed theoretical calculations of several model chemical reactions using the methods combining quantum mechanical and molecular mechanics calculations. The model reactions are 1) altering copolymerization of propylene with carbon monoxide catalyzed by Pd complexes with BINAPHOS ligand, 2) isotactic propylene polymerization catalyzed by a Sm complex, and 3) hydroformylation catalyzed by Rh-BINAPHOS catalysts. As to the first reaction, we first studied with the DFT method the propylene insertion into the PdC bond of Pd(COCH_3)(PH_3)(P(OH)_3)+ to clarify the reaction mechanism and with the MO-then-MM method the retio- and stereoselectivity due to the BINAPHOS ligand. We found that the steric effect due to the BINAPHOS ligand actually controls the stereo- and regioselectivity. In the MO-then-MM calculations of propylene insertion into the Sm-C bond of substituted samarocene alkyl complex, we have found that the propylene insertion would be isotactic, and different from the reaction catalyzed by the d block transition metal complexes, secondary insertion is more favorable. The different control mechanism is operational.

为了分析过渡金属配合物催化选择性反应的机理，为设计催化剂提供有用的信息，我们采用量子力学和分子力学相结合的方法对几个模型化学反应进行了理论计算。模型反应是1）在Pd与BINAPHOS配体的配合物催化下的丙烯与一氧化碳的改变共聚，2）在Sm配合物催化下的等规丙烯聚合，和3）在Rh-BINAPHOS催化剂催化下的加氢。对于第一个反应，我们首先用密度泛函方法研究了丙烯插入Pd（COCH_3）（PH_3）（P（OH）_3）+的PdC键的反应机理，并用MO-then-MM方法研究了BINAPHOS配体的立体选择性。我们发现，由于BINAPHOS配体的空间效应实际上控制立体和区域选择性。在对取代的钐茂烷基配合物的Sm-C键中丙烯插入的MO-then-MM计算中，我们发现丙烯的插入将是全同立构的，并且与d区过渡金属配合物催化的反应不同，丙烯的二次插入更有利。不同的控制机制是可操作的。

项目成果

N.Koga: "Reaction of Samarium Methyl Complex with Ethylene.Ab Initio MO Study." Theor.Chem.Acc.in press.

N.Koga：“甲基钐络合物与乙烯的反应。Ab Initio MO 研究。”

N.KOGA: "Reaction of Samarium Methyl Complex with Ethylene. Ab Initio MO Study." Theoretical Chemistry Accounts. in press.

N.KOGA：“甲基钐络合物与乙烯的反应。从头开始 MO 研究。”

K.Nozaki: "Mechanistic Aspects of the Altering Copolymerization of Propene with Carbon Monoxide Catalyzed by Pd(II) Complexes of Unsymmetrical Phosphine-Phosphite Ligands" J.Am.Chem.Soc.119. 12779-12795 (1997)

K.Nozaki：“不对称膦-亚磷酸盐配体的 Pd(II) 配合物催化丙烯与一氧化碳共聚合的改变机理”J.Am.Chem.Soc.119。

N.Koga: "Reaction of Samarium Methyl Complex with Ethylene. Ab Initio MO Study." Theor.Chem.Acc.(In press).

N.Koga：“甲基钐络合物与乙烯的反应。从头开始 MO 研究。”