Organotransition Metal Chemistry and Catalysis

我们的研究项目涉及有机过渡金属化合物的化学和催化的研究，是一个可以追溯到40多年前的基础和应用研究的长期项目的延伸。我2015年的DG申请描述了三个重要的、相关的研究主题，随着它们在未来五年显著推进，将极大地有助于加拿大金属催化的潜在工业应用。 主题1：烯烃聚合催化中难以捉摸的中间体。在我们的工作之前，研究人员在茂金属催化的烯烃聚合反应中检测到几种类型的短暂中间物种的成功很少。我们解决了这个问题，使用的烯烃可以配位，但由于空间原因，不能进行一次以上的插入反应。结果表明，我们不仅可以用核磁共振观察到不寻常的烷基烯烃物种，而且还可以观察到前所未有的无机盐络合物。这是一个探索[Cp2MMe(烯烃)]+(M=Zr，Hf)类型的络合物的建议，对于这些络合物，我们已经有了引人入胜的初步结果。 研究结果将有助于我们更好地理解这类非常重要的工业催化剂。 主题2.镍对交叉偶联反应的催化作用。与通常使用的钯相比，镍在交叉偶联催化中具有重要的优势，因为除了成本较低外，镍还可用于比钯更多类型的底物。这项建议扩展了我们正在进行的使用钯催化剂的计划，并涉及对几种类型的镍化合物的催化活性的研究。成功将提供通过修饰配体来系统地定制催化剂的机会，以实现不对称和立体收敛的交叉偶联反应。 这些结果除了增加了催化过程的基本知识外，还将对加拿大的制药行业产生明显的潜在好处。 主题3.吲哚膦(Phins)的配位化学这类在很大程度上未被开发的芳香族配体特别令人感兴趣，因为它们与过渡金属结合形成构型稳定的平面手性络合物；因此，它们很可能作为良好的不对称催化剂用于前手性底物的反应，因为催化剂将直接在金属上刚性手性，而不是通常情况下在配体的外围。这项建议描述了几种金属的平面手性化合物的研究，之所以选择这些化合物，是因为它们与其他配体的络合物催化了非常广泛的重要催化反应。与主题2的情况一样，成功的结果将对加拿大的制药业产生明显的潜在好处。 我们的计划将继续，就像它多年来所做的那样，每年培训四到八名本科生、研究生和博士后研究员。

Our research program involves investigations of the chemistry of and catalysis by organotransition metal compounds, and is an extension of a very long term program in basic and applied research which goes back over 40 years. My 2015 DG application describes three important, related research Themes which, as they are significantly advanced over the next five years, will greatly contribute to potential industrial applications of metal catalysis in Canada. Theme 1. Elusive intermediates in alkene polymerization catalysis. Prior to our work, researchers had had very little success in detecting several types of short-lived intermediate species in metallocene catalyzed alkene polymerization reactions. We solved this problem using alkenes which can coordinate but cannot, for steric reasons, undergo more than one insertion reaction. As a result, we show that we can use NMR to observe not only unusual alkyl alkene species but also unprecedented types of agostic complexes. This is a proposal to explore complexes of the types [Cp2MMe(alkene)]+ (M = Zr, Hf) for which we have fascinating preliminary results in hand. The results will contribute greatly to our understanding of this very important class of industrial catalysts. Theme 2. Catalysis of cross-coupling reactions by nickel. Nickel has important advantages over the normally used palladium for cross-coupling catalysis because, in addition to its lower cost, nickel works with many more types of substrates than does palladium. This proposal extends our ongoing program on the use of palladium-based catalysts and involves a study of several types of nickel compounds for their catalytic activities. Success will provide opportunities to systematically tailor catalysts by modifying the ligands in order to to effect asymmetric and stereoconvergent cross-coupling reactions. The results, in addition to adding much to basic knowledge of catalytic processes, will be of obvious potential benefit to Canada's pharmaceutical industry. Theme 3. Coordination chemistry of phosphonium indenylides (PHINs). This largely unexplored class of aromatic ligands is of special interest because they bind to transition metals to form planar chiral complexes which are configurationally stable; thus they may well serve as excellent asymmetric catalysts for reactions of prochiral substrates because the catalysts will be rigidly chiral directly at the metal rather than at the periphery of a ligand as is normally the case. This proposal describes research on planar chiral compounds of several metals, chosen because their complexes with other ligands catalyze a very wide range of important catalytic reactions. As is the case with Theme 2, successful results will be of obvious potential benefit to Canada's pharmaceutical industry. Our program will continue, as it has for many years, to train four to eight undergraduate, graduate and postdoctoral researchers per year.