Pincer-type ligands, complexes, and catalyst design

过渡金属（TM）的有机化学可以说是现代科学的中心领域之一，这是由于TM配合物在石油化学品、药物以及农业和食品工业的化学品的催化有机合成中的应用。这项NSERC发现资助申请中提出的研究解决了几种重要且具有挑战性的均相催化反应类型。部分（a）寻求从天然氨基酸开发手性PNN配体。我们将制作一个家庭的手性PNN钳型配合物的四个金属（Re，Ru，Os，和Ir）的极性C=O和C=N键的不对称氢化和生产手性醇和胺。这种类型的络合物也可用于酯和酰胺的催化还原。部分（B）涉及引入中心亚吡啶（rNHC）片段的新型PCP和PCN卡宾配体的开发。我们的计算数据预测，这样的配体应该作为异常强大的电子供体时，形成钳型配合物。这些钌、锇、铑、铱配合物将被应用于催化碳氢和氮氢键活化、双偶联、脱氢和烃类官能化反应。PCP和PCN钳形碳烯配合物将用于氮氢化，以增强现有的氨技术并开发新的最先进的TM基催化剂。拟议的研究提供了一个很好的机会，培养本科生和研究生在有机过渡金属化学，主族和有机合成，催化和计算化学。

Organometallic chemistry of transition metals (TM) is arguably one of the central areas of modern science owing to the application of TM complexes in catalytic organic syntheses of petrochemicals, pharmaceuticals, and chemicals for agricultural and food industries. The research proposed in this NSERC Discovery grant application addresses several important and challenging types of homogeneously catalyzed reactions. Part (a) seeks to develop chiral PNN ligands from natural amino acids. We will make a family of chiral PNN pincer-type complexes of four metals (Re, Ru, Os, and Ir) for asymmetric hydrogenation of polar C=O and C=N bonds and production of chiral alcohols and amines. Complexes of this type can also be useful for catalytic reduction of esters and amides. Part (b) deals with the development of novel PCP and PCN carbene ligands incorporating a central pyridylidene (rNHC) fragment. Our computational data predict that such ligands should act as exceptionally powerful electron donors when forming pincer-type complexes. These complexes of Ru, Os, Rh, and Ir will be applied in catalytic C-H and N-H bond activation, dehydrogenative coupling, and dehydrogenation and functionalization reactions of hydrocarbons. The PCP and PCN pincer carbene complexes will be explored for nitrogen hydrogenation in an effort to enhance existing ammonia technology and develop new state-of-the-art TM-based catalysts. The proposed research presents an excellent opportunity for training of undergraduate and graduate students in organo-transition metal chemistry, main-group and organic synthesis, catalysis, and computational chemistry.