四甲基二硅桥连二(环已基环戊二烯基)四羰基二铁的合成、结构及热重排反应研究

Synthesis, Structure and Thermal Rearrangement Reaction of Tetramethyldisilane-bridged Bis (cyclohexylcyclopentadienyl) tetracarbonyldiiron

1,2-二(环己基环戊二烯基)四甲基二硅烷与Fe(CO)_5在二甲苯中加热回流生成二铁化合物(Me_2SiSiMe_2)[(c-C_6H_(11)-C_5H3)Fe(CO)]_2(μ-CO)_2(2).通过柱层析分离到2的顺反两种异构体2c和2t,并分别进行热重排反应,发现顺式底物2c重排生成反式重排产物[Me_2Si(c-C_6H_(11)C_5H_3)Fe(CO)_2]_2(3t),而反式底物2t重排则生成顺式重排产物3c.这表明重排反应是立体专一性的。通过X射线衍射分析测定了化合物2c和3t的晶体结构。

The reaction of 1,2-bis(cyclohexylcyclopentadienyl)tetramethyldisilane with Fe(CO)(5) in refluxing xylene afforded a mixture of cis and trans isomers of the diiron complex (Me2SiSiMe2) [(c-C6H11C5H3)Fe(CO)](2)(mu-CO)(2) (2), which were separated by column chromatography. When the two isomers were heated in refluxing xylene, the cis substrate 2c rearranged to the trans product [Me2Si(c-C6H11C5H3)Fe(CO)(2)](2) (3t), while the trans substrate 2t to the cis product 3c. This indicates that the rearrangement reaction is stereospecific. Molecular structures of 3c and 4t were determined by X-ray diffraction analysis.