Cobalt catalyzed hydrogenations: Studies on the stabilization of catalytic intermediates through heteroatom-free pi-acceptor hydrocarbons

这一合作项目包括合成具有不同π-烃配体(即烯烃、芳烃、环戊二烯基)的均相和异相钴配合物，它们在不饱和C=C-和C=X-键体系的催化加氢反应中的应用，以及通过光谱(核磁共振，EPR，MS)，动力学(Kie，中毒)和理论(DFT)方法阐明反应机理。拟议的行动将涉及具有简单烯烃和芳烃配体的富电子钴配合物作为活性和选择性加氢催化剂的适宜性。在低氧化状态下使用钴-芳烃/烯烃预催化剂与具有更高氧化钴原子和杂原子给体配体的钴催化反应在概念上是不同的。在本项目结束时，将与文献中已知的杂原子供体配体/金属络合物进行详细的比较，这可能有助于开发高活性的加氢催化剂。

This collaborative project involves the synthesis of homoleptic and heteroleptic cobalt complexes bearing diverse pi-hydrocarbon ligands (i.e. alkenes, arenes, cyclopentadienyls), their applications to catalytic hydrogenations of unsaturated C=C- and C=X-bond systems, and the elucidation of reaction mechanisms by spectroscopic (NMR, EPR, MS), kinetic (KIE, poisoning) and theoretical (DFT) methods. The proposed actions will address the suitability of electron-rich cobalt complexes with simple alkene and arene ligands as active and selective hydrogenation catalysts. The use of cobalt-arene/alkene precatalysts in low oxidation states is conceptually different from cobalt catayzed reactions with higher oxidized cobalt atoms and heteroatom-donor ligands. At the end of this project, a detailed comparison to literature-known heteroatom-donor ligand/metal complexes will be available which may allow the development of highly active hydrogenation catalysts.