Synthesis Of Iron, Cobalt And Nickel Complexes Bearing A Pincer Ligand And Catalytic Studies Of Iron Hydride Complex

Under certain conditions, cut off the C-H bonds directly and transform them into other functional groups, which will make organic synthesis very efficient and atom economy. Transition metal compounds have incomparable advantages in C-H bonds activation and functionalization. C-H bonds activation and functionalization with transition metal has become a hot research area in organic chemistry. Compared with sp2C-H bonds, sp3C-H bonds are strong σ bonds with high bond energy and thermal stability and difficult to accordinate with metals, so the activation is more difficult. Pincer type ligands have unique double chelate structure and they can easily realize double cyclometallation with metal center, which make the activation of inert bond easier. At present, the sp3C-H activation and functionalization mainly concentrated on precious metals such as Ru, Rh, Pd etc., compared with them, Fe, Co, Ni etc.are unexpensive, easy to get and environmental friendly, so the research about them attracts more and more people’s attention. Transition metal hydrides have good catalytic activity and can be applied to hydrogenation reactions, hydrogen-transfer reactions, hydrosilylation reactions of unsaturated compounds (aldehydes, ketones, alkene, alkyne, etc.).This paper mainly divided into the following two parts, the first part is the synthesis of POCOP ligands with rigid phenyl skeleton, and the reactions with iron, cobalt, nickel compound supported by trimethylphosphine. The reaction with Fe (PMe3)4and CoMe (PMe3)4realize the C-H activation, get compounds1and2, and Ni (PMe3)4and NiMe2(PMe3)4failed to achieve C-H activation, only get simple coordination product4. Iron hydride complex1reacted with methyl iodide to generate3. The structure of compound1,2,3,4were characterized by IR, NMR, X-ray single crystal diffraction. In the second part, iron hydride compound1was used as catalyst,(EtO)3SiH was used as hydrogen source in THF at65℃, hydrosilylation of aldehydes ketones is realized. We further hydrolyzed silicon ether, obtained the corresponding alcohols compound. The alcohol compounds were characterized by HNMR.