Sterically and Electronically Designed Metal Species for Reactions

用于反应的空间和电子设计金属物质

基本信息

批准号：
17550102
负责人：
YASUDA Makoto
金额：
$ 2.24万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17550102/
关键词：
Lewis acid Indium Boron Silicon Cage-Shape Steric Effect Selectivity Catalyst

项目摘要

A structurally strained borate was generated in the reaction of tris(2-hydoxyphenyl)methane with borane. The formed boron species has a cage-shape and a pyramidal structure around the boron metal. The cage-shape and structural strain enhance the Lewis acidity and catalytic turn-overs. The cage-shaped borate catalyzed the allylation of benzaldehyde with allyltributyltin, while phenyl borate B(OPh)_3,which has a planar structure, did not show catalytic acitivity. Its pyridine complex was analyzed by NMR which shows strong interaction of the borate with pyridine and a tetrahedral structure around the metal. The pyridine complex in solid state was characterized by X-ray crystallography. Boron has a tetrahedral coordination sphere with the average of bond angles (O-B-O,114.2(9)° and N-B-O,104.1(9)°). The structure without pyridine shows C_3 symmetry. The aromatic rings deviate from a perpendicular plane to that of three oxygens (ca.19.2°) and thus, the pyridine-complex has chiality that is caused by the cage-shape.The combined Lewis acid system using indium and silicon showed very high activity of some reactions. An NMR study clearly showed the interaction of the indium with silicon mediated by Cl as a bridged atom. The high Lewis acidity showed up on the silicon center in situ. The high oxophilicity accelerated the direct subsitution of alcohols in a catalytic manner. The catalyst system accomplished the catalytic substitution of alcohols in a halogen-free solvent. The system is considered to be an ideal and practical process for industrial chemisty.

在Tris（2-羟基苯基）甲烷与硼烷的反应中产生了结构上紧张的硼酸盐。形成的硼物种在硼金属周围具有笼子形状和锥体结构。笼形和结构应变增强了刘易斯的酸度和催化转折。笼形的硼酸盐用全甲丁基蛋白催化了苯甲醛的全元，而具有平面结构的苯基硼酸盐B（OPH）_3并未表现出催化效率。通过NMR分析了其吡啶络合物，该吡啶复合物在金属周围显示出硼酸酯与吡啶和四面体结构的强烈相互作用。固态的吡啶复合物的特征是X射线晶体学。硼的平均值（O-B-O，114.2（9）°和N-B-O，104.1（9）°）具有四面体配位球体。没有吡啶的结构显示C_3对称性。芳族环从垂直平面偏离了三个氧气（约19.2°）的垂直平面，因此，吡啶 - 复合物具有由笼形形状引起的尖锐性。使用Indium和Silicon组合的路易斯酸系统表现出某些反应的极高活性。 NMR的一项研究清楚地表明，由Cl作为桥接原子介导的硅与硅的相互作用。高刘易斯酸度位于原位硅中心。高氧素性以催化方式加速了酒精的直接延展。催化剂系统在无卤素溶液中实现了醇的催化取代。该系统被认为是工业化学的理想且实用的过程。