- Aluminium, gallium and indium complexes supported by a chiral phenolato-prolinolato dianionic ligand
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Congeneric complexes (S)-{?O}MCH2SiMe3 (M=Al, 3; Ga, 5; In, 6) of the triel metals supported by an enantiomerically pure phenolato-alkoxo {?O}2- dianionic tridentate ligand derived from prolinol, along with their chloro derivatives, have been prepared and characterised. The aluminium-alkyl species (S)-{?O}AlMe and 3 form four-coordinate complexes with slightly distorted tetrahedral geometries, whereas the geometry in the Lewis acidic five-coordinate (S)-{?O}GaCl·THF is a distorted trigonal bipyramid. These alkyl complexes do not react cleanly, if at all, with protic sources. The indium(III) compound 6, which is for instance inert towards iPrOH or BnOH even after hours at 70°C, catalyses at 95°C the controlled, immortal ring-opening polymerisation of racemic lactide (up to 1000 equivalents) in the presence of excess BnOH as a chain transfer agent. It affords atactic, monodisperse polylactides with predictable molecular weights.
- Maudoux, Nicolas,Tan, Eric,Hu, Yuya,Roisnel, Thierry,Dorcet, Vincent,Carpentier, Jean-Fran?ois,Sarazin, Yann
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- Dinuclear Aluminum Poly(phenolate) Complexes as Efficient Catalysts for Cyclic Carbonate Synthesis
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A series of dinuclear aluminum complexes 1-4 stabilized by amine-bridged poly(phenolato) ligands have been synthesized, which are highly active in catalyzing the cycloaddition of epoxides and CO2. In the presence of 0.3 mol % complex 3 and 0.9 mol % NBu4Br at 1 bar CO2 pressure, terminal epoxides bearing different functional groups were converted to cyclic carbonates in 60-97% yields. Complex 3 is one of the rare examples of Al-based catalysts capable of promoting the cycloaddition at 1 bar pressure of CO2. Moreover, reactions of more challenging disubstituted epoxides also proceeded at an elevated pressure of 10 bar and afforded cyclic carbonates in 52-90% yields.
- Gao, Pengfei,Zhao, Zhiwen,Chen, Lijuan,Yuan, Dan,Yao, Yingming
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- NOVEL CERIUM COMPLEX, AND LIGHT EMITTING MATERIAL
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PROBLEM TO BE SOLVED: To provide a novel cerium carbene complex suitable for LED phosphors, organic EL emission layer materials, wavelength conversion materials for solar cells, and wavelength conversion materials for agriculture facility, and a method of producing the same. SOLUTION: The present invention provides a cerium complex with trivalent cerium coordinated with a carbene compound; particularly, a cerium complex in which the carbene compound coordinated to trivalent cerium being represented by formula (1). (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10 each represent a hydrogen atom, or a C1-20 hydrocarbon group, or a hydrocarbon group containing an oxygen atom or a phosphorus atom, where they may be bound to each other, to form a ring. R11, R12 each represent a hydrogen atom or a C1-20 hydrocarbon group, where they may be bound to each other, to form a ring. x is an integer of 0 to 10). SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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- Enantioselective ring opening of meso-epoxides with aromatic amines catalyzed by dinuclear magnesium complexes
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The dinuclear magnesium complexes generated in situ from the reaction of chiral multidentate semi-azacrown ether ligands with n-Bu2Mg were found to be efficient catalysts for enantioselective ring-opening of meso-epoxides with aniline derivativ
- Bao, Hongli,Wang, Zheng,You, Tianpa,Ding, Kuiling
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- Magnesium and zinc complexes containing pendant pyrazolyl-phenolate ligands as catalysts for ring opening polymerisation of cyclic esters
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Reactions of HOPhtBu(CH2)Pz {4,6-di-tert-butyl-2- (pyrazol-1-yl-methyl)phenol} or HOPhtBu(CH2)Pz Me {4,6-di-tert-butyl-2-(3,5-dimethylpyrazol-1-yl-methyl)phenol} with 1.1 equivalent of MgnBu2 in toluene gave the binuclear compounds (nBuMgOPhtBu(CH2)Pz)2 (1) or (nBuMgOPhtBu(CH2)PzMe) 2 (2). Treatment of HOPhtBu(CH2)Pz or HOPh tBu(CH2)PzMe with 1.1 equivalent of ZnEt 2 in n-hexane yielded binuclear compounds (EtZnOPh tBu(CH2)Pz)2 (3) and (EtZnOPh tBu(CH2)PzMe)2 (4). Colourless crystals of (ClZnOPhtBu(CH2)Pz)2 (5) were obtained via the recrystallisation of 3 from a concentrated dichloromethane solution at room temperature. Alternative route for the synthesis of 5 can be achieved via the reaction of HOPhtBu(CH2)Pz with 1.1 equivalent of n-butyllithium in diethylether followed by the treatment of 1.1 equivalent of ZnCl2 in tetrahydrofuran gave compound 5 as binuclear chloride complex. The compounds 2 and 5 were crystallographically characterised. The catalytic activities of 1-5 towards the ring opening polymerisation reactions of cyclic esters in the presence of benzyl alcohol were under investigation.
- Chen, Chi-Tien,Hung, Chia-Chi,Chang, Yu-Jen,Peng, Kuo-Fu,Chen, Ming-Tsz
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