Synthesis,Structure And Reactivity Of Rare-earth Metal Complexes Incorporating Chiral Cyclonexyl Bridged Bis(β-diketiminato) Or β-ketoiminate Ligands

A series of cyclohexyl bridged bis（β-diketiminato）compounds Cy[NHC（Me）CHC（Me）NAr]₂（Cy =（1R,2R）-（-）-1,2-cyclohexyl,Ar = 2,6-iPr₂C₆H₃（1）,Ar = 2,6-Me₂C₆H₃（2）;Cy =（1S,2S）-（+）-1,2-cyclohexyl,Ar = 2,6-Et₂C₆H₃（3）;Cy = Trans-1,2-cyclohexyl,Ar = 2,6-iPr₂C₆H₃（4））and Cy[NC（Me）CHC（OH）（Me）]₂（Cy =（1R,2R）-（-）-1,2-cyclohexyl）（5）were synthesized in good yields.Treatment of cyclohexyl bridged bis（β-diketiminato）or β-ketoiminate ligands with[（Me₃Si）₂N]₃RE^Ⅲ（μ-Cl）Li（THF）₃ afforded series of novel rare earth metal complexes bearing cyclohexyl bridged bis（β-diketiminato）or P-ketoiminate ligands in good yields.Application in organic synthesis or magnetic properties of the above rare earth metal complexes has also been further examined.The thesis consists of the following sections:1.A series of novel five coordinate rare earth metal alkylides with general formula{Cy[NC（Me）CHC（Me）NAr]₂}RECH₂SiMe₃[RE = Dy（6）,Er（7）,Yb（8）,Y（9）]were synthesized in good yields via reaction of RE[CH₂SiMe₃]₃（THF）₂ with the corresponding chiral diamine Cy[NHC（Me）CHC（Me）NAr]₂（Cy =（1R,2R）-（-）-1,2-cyclohexyl,Ar = 2,6-iPr₂C₆H₃（1））.The structures of all complexes were determined by single-crystal X-ray analyses.The catalytic activity of complexes 6-9 for the hydroamination/cyclization of aminoalkenes were evaluated,and results indicated that the complexes exhibited high catalytic activity and good enantioselectivity,afforded Markovnikov products.Under the same amount of catalyst and reaction temperature,the construction of a nitrogen-containing six-membered heterocyclic ring required a longer reaction time.2.A series of five coordinate rare earth metal amides with general formula{Cy[NC（Me）CHC（Me）NAr]₂}REN（SiMe₃）₂[RE = Nd（10）,Dy（11）,Yb（12）,Y（13）]were synthesized in good yields via reaction of[（Me₃Si）₂N]₃REm（μ-Cl）Li（THF）₃ with the corresponding chiral diamine Cy[NHC（Me）CHC（Me）NAr]₂（Cy =（1S,2S）-（+）-1,2-cyclohexyl,Ar = 2,6-Et₂C₆H₃（3））.Reaction of[（Me₃Si）₂N]₃RE^Ⅲ（μ-Cl）Li（THF）₃ with the chiral cyclohexyl bridged bis（β-diketiminato）compound 1 also afforded the corresponding rare earth metal amides with general formula {Cy[NC（Me）CHC（Me）NAr]₂}REN（SiMe₃）₂[RE=Nd（14）,Gd（15）,Dy（16）,Er（17）,Y（18）]in good yields.All compounds were fully characterized by spectroscopic methods and elemental analyses.The structures of complexes 10-13 were determined by single-crystal X-ray analyses.The catalytic activities of rare-earth complexes for diphenyphosphine oxide to β-nitroalkene or a,p-unsaturated carbonyl derivatives were investigated.The results indicated that all complexes exhibited a high catalytic activity towards the addition of diphenyphosphine oxide to β-nitroalkene and a,P-unsaturated carbonyl derivatives.3.Reaction of[（Me₃Si）₂N]₃RE^Ⅲ（μ-Cl）Li（THF）₃ with the trans-cyclohexyl bridged bis（β-diketiminato）compound 4 gave a series of rare earth metal amides with general formula {Cy[NC（Me）CHC（Me）NAr]₂}REN（SiMe₃）₂[RE = Nd（19）,Sm（20）,Dy（21）,Er（22）,Y（23）]in good yields.All compounds were fully characterized by spectroscopic methods and elemental analyses.The structures of all complexes were determined by single-crystal X-ray analyses.Catalytic activities of complexes 19-23 for hydrophosphonylation of aldehydes and ketones were developed,and results showed that these complexes exhibited a high catalytic activity towards the hydrophosphonylation of aldehydes and ketones in the presence of a very low loading of rare-earth metal amides at room temperature in a short time.4.Reaction of rare-earth metal[（Me₃Si）₂N]₃RE（μ-Cl）Li（THF）3 with 3/2 equiv of chiral ligand Cy[NC（Me）CHC（OH）（Me）]₂（Cy =（1R,2R）-（-）-1,2-cyclohexyl）（5）produced two oxygen-bridged dinuclear rare-earth metal complexes{Cy[NC（Me）CHCO（Me）]₂}₃RE₂[RE = Dy（24）,Eu（25）].Reaction of rare-earth metal[（Me₃Si）₂N]₃RE（μ-Cl）Li（THF）₃ with 4/3 equiv of chiral ligand 5 produced two oxygen and nitrogen-bridged trinuclear rare-earth metal complexes{Cy[NC（Me）CHCO（Me）]₂}₃RE₃ {Cy[NC（Me）CHCO（Me）][NC（CH₂）CHCO（Me）]}[RE = Y（26）,Gd（27）].Reaction of rare-earth metal[（Me₃Si）₂N]₃Yb（μ-Cl）Li（THF）₃ with 1 equiv of chiral ligand 5 produced chlorine and oxygen-bridged tetranuclear ytterbium complexe {Cy[NC（Me）CHCO（Me）]₂}₄（μ₂-Cl）₂（μ₃-Cl）₂Yb₄（28）.Reaction of rare-earth metal[（Me₃Si）₂N]₃RE（μ-Cl）Li（THF）3 with 2 equiv of chiral ligand 5 produced mixed polynuclear neodymium complex{Li（Cy[NC（Me）CHCO（Me）]₂）₂Nd}₁₀（29）.All compounds were fully characterized by spectroscopic methods and elemental analyses.The structures of all complexes were determined by single-crystal X-ray analyses.Preliminary studies revealed that complex 24 have the behavor of Single-Molecular Magnets.