作者:Peter G. Edwards、K. M. Abdul Malik、Li-ling Ooi、Andrew J. Price
DOI:10.1039/b509627h
日期:——
Primary and secondary phosphine piano-stool complexes of the type [η5-CpFeL3]+
(L = phenylphosphine, 3, (α-methyl)vinylphosphine, 4, allylphosphine, 5, (2-methylpropenyl)phosphine, 5b, allyl(phenyl)phosphine, 6) are described. The alkenyl phosphine complexes, 5 and 6, react by intramolecular hydrophosphination to give the corresponding [η5-CpFe]+ complexes of 1,5,9-triphosphacyclododecane (12-aneP3R3, 2, R = H), 9 and 10 respectively. Alkylation of the secondary phosphines in 9 is achieved by hydrophosphinations with ethene to give the 12-aneP3R3
(R = Et) derivative 11. These complexes are also obtained by reaction of suitable [η5-CpFe]+ containing precursor complexes with the corresponding free 12-aneP3R3 macrocycle as is the related [η5-Cp*Fe]+ derivative, 8. Direct substitution of acetonitrile in [Fe(CH3CN)6][BF4]2 by 12-aneP3Et3, leads to the macrocycle piano-stool complex, [(12-aneP3Et3)Fe(CH3CN)3][BF4]2, 7. The crystal structures of selected primary phosphine, η5-Cp, η5-Cp* complexes and 7, allow a comparison of steric influences upon key macrocycle ring closure reactions and hence an insight into parameters required for the formation of smaller ring sizes by template based methods.
描述了[η5-CpFeL3]+(L =苯基膦,3;(α-甲基)乙烯基膦,4;烯丙基膦,5;(2-甲基丙烯基)膦,5b;烯丙基(苯基)膦,6)类型的伯和仲膦钢琴络合物。烯基膦络合物 5 和 6 通过分子内水磷化反应,分别得到 1,5,9-三膦酰环十二烷(12-aneP3R3, 2, R = H)的相应 [η5-CpFe]+络合物 9 和 10。9 中的仲膦通过与乙烯的氢化膦反应进行烷基化,得到 12-aneP3R3 (R = Et) 衍生物 11。与相关的 [η5-Cp*Fe]+ 衍生物 8 一样,这些配合物也可以通过含有适当 [η5-CpFe]+ 的前体配合物与相应的游离 12-aneP3R3 大环反应得到。用 12-aneP3Et3 直接取代[Fe(CH3CN)6][BF4]2 中的乙腈,可得到大环钢琴凳配合物[(12-aneP3Et3)Fe(CH3CN)3][BF4]2,7。通过选定的伯胺膦、η5-Cp、η5-Cp* 复合物和 7 的晶体结构,可以比较关键大环闭环反应的立体影响,从而了解通过基于模板的方法形成较小尺寸环所需的参数。