Transition Metal Complexes with Chiral Pincer Ligands: Reactions, Catalyses, Mechanisms

本研究项目涉及手性钳形配体作为立体定向配体在对映选择性催化中的配位化学。一个主要的目标将是评估这类配体在多大程度上可以在不同范围的对映体选择性转化中为肌萎缩侧索硬化症的“特权”立体定向配体系统服务。计划研究的目的将是分离和表征作为这些3D金属对映体选择性催化还原的关键中间体的(高自旋)锰、铁、钴和镍配合物的氢化物和硼酸衍生物，以及将分离的配合物用于化学计量比和催化还原的系统动力学研究。此外，我们的目标是开发基于最近发现的Ni(I/II)催化的以O2为共底物的径向氧化反应的高效氧化催化剂，并将继续对这些转化进行更深入的机理研究。最后，我们计划研究黄锰络合物作为酮的对映选择性α-酰氧基化的可能催化剂，反应机理(S)，并鉴定所涉及的(电子开壳层，顺磁性)络合物。

The research project concerns the coordination chemistry of such chiral pincer ligands as stereodirecting ligands in enantioselective catalysis. A main objective will be to assess to which extent this class of ligands may serve als "privileged" stereodirecting ligand systems in a diverse range of enantioselective transformations. An aim of the planned research will be the isolation and characterization of (high spin) hydrido and boranato-derivatives of Boxmi-manganese, iron, cobalt and nickel complexes as key intermediates of enantioselective catalytic reductions with these 3d metals as well as the use of the isolated complexes in systematic kinetic studies of the stoichiometric and catalytic reductions. Furthermore, we aim to develop efficient oxidation catalysts based on the recently discovered Ni(I/II) catalyzed radikal oxygenations with O2 as co-substrate, and ongoing mechanistic studies of these transformations will be continued and pursued to greater depth. Finally we plan to investigate Boxmi-manganese complexes as possible catalysts for the enantioselective alpha-acyloxylation of ketones, the reaction mechanism(s) and identify the (electronically open shell, paramagnetic) complexes involved.