| In recent decades, asymmetric catalysis of unsaturated compounds containing carbonyl group has attracted much attention. Especially since 1990s, the study on asymmetric catalysis using late transition metal (Rh, Ru, Ir) complexes containing NH functionality has made a rapid progress. Noyori won the Nobel Prize in 2001 for his excellent study on asymmetric catalysis.In the reported studies about asymmetric catalysis using transition metal complexes containing NH functionality as catalysts are mainly concentrated on expensive metals, such as Rh,Ru,Ir. Much less studies were made on 3d transition metals. Our aim in this work is to use the much cheaper metal Ni as the metal center to synthesize the similar catalysts contaning NH functionalities and to investigate their catalytic hydrogenation of ketones. In this thesis, we have managed to synthesize a series of nickel complexes, and six among of them were selected to study the catalysis of hydrogenation of ketones.1. The reactions of NiCl2 with ethylenediamine (en), o-phenylene diamine (opda), or N,N,N',N'-tetramethylethylenediamine (tmen) gave [Ni(en)(2,2′-bipy)(H2O)2]Cl2 (1), [Ni(en)(H2O)2(tmen)]Cl2·2H2O (2) and [Ni(opda)(Phen)Cl2]CH3OH (3), respectively. Complex 1 crystallizes in the monoclinic space group P21/c with a = 14.132(5) A, b = 8.371(3) A, c = 15.454(6) A,β= 115.734(5)°. Complex 2 crystallizes in the Orthorhombic space group Pbcn with a = 15.005(4) A, b = 9.591(3) A, c = 12.505(3) A. Complex 3 crystallizes in the monoclinic space group C2/c with a = 13.898(4) A, b = 18.246(5) A, c = 10.015(3) A,β= 126.313(3)°.2. The reactions using NiCl2 and diaminocyclohexane (dach) or (R, R)-(+)-1,2- diphenylenediamine ((R, R)-dpen) as the main starting materials provided [Ni(dach)(tmen)(H2O)2]Cl2·2H2O (5), [Ni(dach)(2,2′-bipy)2(Cl)2]·2H2O (6), [Ni2((R, R)-dpen)4(H2O)2Cl2]Cl2·CH3CH2OCH3 (8), [Ni((R, R)-dpen)(phen)(CH3OH)2]Cl2 (9), [Ni2((R, R)-dpen)2(phen)2(Cl)2(H2O)2]Cl2 (10) and [Ni((R, R)-dpen)(tmen)(H2O)2]Cl2 (11). Complex 5 crystallizes in the Orthorhombic space group Ibam with a = 14.160(2) A, b = 9.8435(14) A, c = 15.221(2) ?. Complex 6 crystallizes in the monoclinic space group C2/c with a = 15.270(15) A, b = 17.732(17) A, c = 10.244(10) A,β= 127.535(10)°. Complex 8 crystallizes in the Triclinic space group P1with a = 9.738(7) A, b = 10.439(8) A, c = 16.418(12) A,α= 105.044(11)°,β= 98.591(10)°,γ= 90.003(11)°. Complex 9 crystallizes in the monoclinic space group C2/c with a = 15.270(15) A, b = 17.732(17) A, c = 10.244(10) A,β= 127.535(10)°. Complex 10 crystallizes in the monoclinic space group P21/n with a = 12.378(3) A, b = 13.836(3) A, c = 21.279(5) A,β= 1101.273(3)°. Complex 11 crystallizes in the Triclinic space group Pīwith a = 9.017(3) A, b = 11.690(4) A, c = 13.095(5) A,α= 77.431(4)°,β= 89.984(4)°,γ= 69.298(5)°.3. Another three compounds [Ni2(dant)4(DMF)2Cl2]Cl2·3H2O (12), [en(phen)24H2O]Cl2 (14) and [Ni(datm)2] (13) were isolated from the reactions of NiCl2 with 1,8-diaminonaphthalene (dant) or diacetamide (datm): 12 and 14 crystallize in the monoclinic space group P21/c with a = 15.0758(10) A, b = 22.7726(15) A, c = 16.3817(11) A,β= 113.3880(10)°for 12 and a = 8.822(2) A, b = 11.832(3) A, c = 15.635(3) A,β= 119.190(3)°for 14. 13 crystallizes in the triclinic space group P1 with a = 7.6518(8) A, b = 9.8985(10) A, c = 10.6525(11) A,α= 69.492(2)°,β= 70.416(2)°,γ= 80.602(2)°.4. Complexes 3, 4, 8, 9, 12 and 15 were selected to perform the asymmetric catalytic hydrogenation of ketones. Three kinds of asymmetric catalytic hydrogenation were carried out: (a) catalytic ionic hydrogenations using H2 as hydrogen source, (b) transfer hydrogenation using isopropanol as hydrogen source, (c) transfer hydrogenation using formic acid-triethylamine as hydrogen source. The products are checked by GC. The results revealed that these complexes show nice catalytic effects in catalytic ionic hydrogenations. Among of them a 72.1% conversion of acetophenone into the corresponding alcohol was found in the catalytic hydrogenation of ketone using complex 12 as catalyst. However they present nearly no catalytic effects in transfer hydrogenation using both isopropanol and formic acid-triethylamine as hydrogen source. |
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