作者:Andrew P. Dove、Vernon C. Gibson、Pimpa Hormnirun、Edward L. Marshall、John A. Segal、Andrew J. P. White、David J. Williams
DOI:10.1039/b303550f
日期:——
A series of magnesium(II) alkyl, alkoxide, carboxylate, amide and halide complexes stabilised by the bulky β-diketiminate ligand, HC(C(Me)N-2,6-iPr2C6H3)2
(BDI), have been synthesised and structurally characterised. (BDI)H reacts with MgMe2 in Et2O to give the four-coordinate complex (BDI)MgCH3(Et2O), 1, and in toluene to afford [(BDI)Mg(μ-CH3)]2, 2. Three coordinate complexes may be accessed by increasing the size of the alkyl ligand; hence, the reaction of (BDI)H with tBu2Mg yields (BDI)MgtBu, 3, while Li(BDI) reacts with iPrMgCl to afford (BDI)MgiPr, 4; a similar reaction with PhMgCl affords the diethyl ether adduct (BDI)MgPh(Et2O), 5. The etherates 1 and 5 may be converted into the base-free complexes, 2 and (BDI)MgPh, 6, respectively, upon heating in vacuo. The direct reaction of (BDI)H with RMgX (X = Cl or Br) results in relatively inert halide-bridged dimers of formula [(BDI)Mg(μ-X)]2, (X = Cl, 7; X = Br, 8). The alkylmagnesium derivatives react readily with alcohols, amines or carboxylic acids to yield alkoxide, amide and carboxylate complexes, respectively. For example, 4 reacts with iPrOH (or O2) to form [(BDI)Mg(μ-OiPr)]2, 9. Convenient one-pot synthetic procedures have been developed using commercially available Bu2Mg. Treatment of Bu2Mg with (BDI)H, followed by its reaction with MeOH, tBuOH, iPr2NH, (Me3Si)2NH, MeCO2H or PhCO2H affords [(BDI)Mg(μ-OMe)]2, 10, [(BDI)Mg(μ-OtBu)]2, 11, (BDI)Mg(NiPr2), 12, (BDI)Mg(NTMS2), 13, [(BDI)Mg(μ-O2CMe])]2, 14, and [(BDI)Mg(μ-O2CPh)]2, 15, respectively. The molecular structures of complexes 4â8 and 12â15 are reported.
一系列由庞大β-二酮亚胺配体HC(C(Me)N-2,6-iPr2C6H3)2(BDI)稳定的镁(II)烷基、烷氧化物、羧酸盐、氨基和卤化物配合物已被合成并结构表征。(BHDI)与MgMe2在Et2O中反应得到四配位的配合物(BHDI)MgCH3(Et2O),1,在甲苯中得到[(BHDI)Mg(μ-CH3)]2,2。通过增大烷基配体的大小可以获得三配位配合物;因此,(BHDI)H与tBu2Mg反应生成(BHDI)MgtBu,3,而Li(BHDI)与iPrMgCl反应得到(BHDI)MgiPr,4;类似的反应与PhMgCl生成二乙醚加合物(BHDI)MgPh(Et2O),5。醚合物1和5在真空加热下分别转化为无碱配合物2和(BHDI)MgPh,6。(BHDI)H与RMgX(X = Cl或Br)的直接反应生成相对惰性的卤素桥联二聚体,分子式为[(BHDI)Mg(μ-X)]2,(X = Cl,7;X = Br,8)。烷基镁衍生物易于与醇、胺或羧酸反应,分别生成烷氧化物、氨基和羧酸盐配合物。例如,4与iPrOH(或O2)反应生成[(BHDI)Mg(μ-OiPr)]2,9。采用商业上可获得的Bu2Mg,开发了方便的一锅合成程序。Bu2Mg与(BHDI)H反应,随后与MeOH、tBuOH、iPr2NH、(Me3Si)2NH、MeCO2H或PhCO2H反应,分别得到[(BHDI)Mg(μ-OMe)]2,10,[(BHDI)Mg(μ-OtBu)]2,11,(BHDI)Mg(NiPr2),12,(BHDI)Mg(NTMS2),13,[(BHDI)Mg