New Aspects of Early d-Block Metal Aryloxide Chemistry

Ian P. Rothwell博士，普渡大学化学系，由化学系无机、生物无机和有机金属化学项目支持，研究早期过渡金属羰基氧化物化学。该项目的中心主题涉及使用立体大体积的芳基氧化物连接来支持过渡金属中心的不饱和小分子的化学反应和催化反应活性。研究的目的是了解氧化钛催化[2+2+1]乙炔三聚化反应的机理，并开发该反应的合成用途。新的C2对称手性芳氧化合物将被用作单齿支撑配体来进行不对称碳-碳成键反应。对控制手性物质的动力学和热力学分解的因素进行基础研究。最后，制备阳离子金属环铌钽配合物。与过渡金属结合在一起的空间体积大的基团通常能有效地阻止一定尺寸和形状的反应物进入金属中心。因此，确实发生的反应产生具有首选几何形状的产物。在本研究中，大块的醇氧基将用于影响一些早期过渡金属促进反应的立体特异性反应，在有机化合物的合成中具有实用性。

Dr. Ian P. Rothwell, Department of Chemistry, Purdue University, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program of the Chemistry Division, for research into early transition metal aryloxide chemistry. The central theme of the project involves the use of sterically bulky aryloxide ligation to support both stiochiometeric and catalytic reactivity of unsaturated small molecules at transition metal centers. Studies will aim toward a mechanistic understanding of titanium-aryloxide catalyzed [2+2+1] acetylene trimerization and the development of the synthetic utility of the reaction. New C2 symmetric, chiral aryloxides will be used as monodentate supporting ligands to carry out asymmetric carbon-carbon bond forming reactions. Fundamental studies of the factors controlling both kinetic and thermodynamic resolution of the chiral species will be carried out. Finally, cationic metallacyclic niobium and tantalum complexes will be prepared. Sterically bulky groups bound to transition metals are often effective in preventing reactants of certain size and shape from accessing the metal center. As a consequence, the reactions that do occur produce products with a preferred geometry. In this study, bulky alkoxide groups will be used to effect stereospecific reactivity to some early transition metal promoted reactions of utility in the synthesis of organic compounds.