Synthesis Of Silyl Pincer Fe,Co And Ni Complexes Supported With Trimethylphosphine And Their Applications In Catalytic Reactions

Organic chemistry plays a very important roleduring the development of human society,the synthesis and functionalization reactionof compounds containing inert bonds have been occupying the frontier of Organic chemistry.In recent decades,the activation of silicon hydrogen bonds in the field of inert bonds activation has attracted more and more attention from researchers.In the beginning,the research focused on complexes containing precious metals to activate the silicon hydrogen bonds,however,the use of cheap transition metals to participate in the activation of silicon hydrogen bond is on the increase.Lots of researches have found that the activation mechanism of small molecule compounds containing silicon hydrogen bondsis relatively simple.Nowadays,the activation of silicon hydrogen bonds in the ligands containing anchored atoms(such as nitrogen or phosphorous)has being taken more attentions.The metal complexes produced by activating silicon hydrogen bond have very important application value in the study of property and catalytic reaction.In recent years,the activation of silicon hydrogen bonds has been mainly focused on the following aspects:the synthesis of nitrogen adduct and the reduction of nitrogen by nitrogen adduct;the capture of CO2 and application in transfer hydrogenation reaction of carboxylic acid using CO2 as raw material;the hydrogenation of aldehydes and kentones;the borohydrogenation reaction of alkenes and alkynes.The application of metal complexes containing silicon atoms can be seen in these fields.In conclusion,the design,synthesis and application of compounds containing silicon hydrogen bondis an important direction of development of organic chemistry in the future.The main contents of this paper are the synthesis of[PSiP]and[P,Si]containing iron,cobalt and nickel and the applications of these complexes in catalytic reaction.The research includes four parts as follows:1.We used P as anchoring group to designed different kinds of silyl ligands and combined with Fe(PMe3)4,Co(PMe3)4,CoMe(PMe3)4,CoCl(PMe3)3 to generate a series of new silyl transition-metal complexes through the activation of Si-H bonds.Threetridentate[PSiP](L1,L2,L3)silyl ligands were synthesized and a new bidentate ligand(phosphino)silyl ligand([P,Si]L4)was synthesized.The isopropyl on the auxiliary molecule of the[PSiP]ligands and[P,Si]result in the unique electronegativity and space resistanceof these ligands.2.The metal complexes with unique electronegativity and space resistancewere applied to the hydrogenation and hydrosilylation of carbonylcompound,the catalytic reaction of amide reduction,and the catalysts showed good catalytic effect in the reaction.Furthermore,treatment these tridentate ligands or bidentate ligands with CoCl(PMe3)3 generatedCo(III)complexes.These Co(III)complexes were excellent catalysts in the kumada coupling reaction.3.The hydrogenation of carbondioxide to formate was explored.We used the hydrido ironsilyl pincer complex ascatalyst to investigate the influence of base andreactionpressure.4.The cobalt-dinitrogen complexwas found to work as effective catalyst toward the direct conversionof molecular dinitrogen into silylamine under mild reaction conditions.