Insertion of Carbon Monoxide into Nickel-Alkyl Bonds of Monoalkyl-and Dialkylnickel(II) Complexes, NiR(Y)L<sub>2</sub>and NiR<sub>2</sub>L<sub>2</sub>. Preparation of Ni(COR)(Y)L<sub>2</sub>from NiR(Y)L<sub>2</sub>and Selective Formation of Ketone, Diketone, and Aldehyde from NiR<sub>2</sub>L<sub>2</sub>
作者:Takakazu Yamamoto、Teiji Kohara、Akio Yamamoto
DOI:10.1246/bcsj.54.2161
日期:1981.7
Reactions of monoalkylnickel(II) complexes, NiR(Y)L2 (R=CH3, C2H5; Y=Cl, suc(succinimido), pht(phthalimido), OC6H4-p-CN; L=1/2 bpy (2,2′-bipyridine), PEt3 (triethylphosphine)), with CO afford monoacylnickel(II) complexes, Ni(COR)(Y)L2, which are characterized by elemental analysis and spectroscopies (IR and NMR). Reactions of the acylnickel(II) complexes with alcohols and aniline give the corresponding esters and amides, respectively. Exposure of Ni(COR)(Y)L2 to dry air leads to oxidation of RCO to a RCOO ligand giving a complex formulated as Ni(OCOR)(Y)L2. Reactions of dimethylnickel(II) complexes, Ni(CH3)2L2 (L=1/2 bpy, PEt3, 1/2 dpe (1,2-bis(diphenylphosphino)ethane, 1/2 dpp (1,3-bis(diphenylphosphino)propane), with carbon monoxide afford acetone and/or 2,3-butanedione in medium to high yields, the acetone/2,3-butanedione ratio varying with the ligand L, reaction temperature, and additives such as maleic anhydride and triphenylphosphine. Generally the acetone/2,3-butanedione ratio decreases with increase in thermal stabilities of Ni(CH3)2L2. Ni(C2H5)2(bpy) and Ni(n-C3H7)2(bpy) give 3-pentanone and 4-heptanone, respectively, on treating them with CO, whereas Ni(C2H5)2(dpe) produces C2H5CHO and C2H4.
甲基或乙基镍(II)配合物NiR(Y)L2 (R=CH3, C2H5; Y=Cl, succ(琥珀酰亚胺), pht(酞酰亚胺), OC6H4-p-CN; L=1/2 bpy (2,2'-联吡啶), PEt3 (三乙基膦))与CO反应生成单酰基镍(II)配合物Ni(COR)(Y)L2, 该化合物通过元素分析和光谱学(IR和NMR)进行表征。酰基镍(II)配合物与醇和苯胺反应生成相应的酯和酰胺。将Ni(COR)(Y)L2暴露于干燥空气中会导致RCO氧化成RCOO配体, 生成化学式为Ni(OCOR)(Y)L2的配合物。二甲基镍(II)配合物Ni(CH3)2L2 (L=1/2 bpy, PEt3, 1/2 dpe (1,2-双(二苯基膦)乙烷), 1/2 dpp (1,3-双(二苯基膦)丙烷))与一氧化碳反应生成中等至高产率丙酮和/或2,3-丁二酮, 丙酮/2,3-丁二酮的比例随配体L、反应温度和马来酸酐及三苯基膦等添加剂的不同而变化。通常, 随着Ni(CH3)2L2热稳定性的增加, 丙酮/2,3-丁二酮的比例下降。Ni(C2H5)2(bpy)和Ni(n-C3H7)2(bpy)用CO处理分别生成3-戊酮和4-庚酮, 而Ni(C2H5)2(dpe)生成C2H5CHO和C2H4.