Synthesis, Structure, and Reactivity of the Ethyl Yttrium Metallocene, (C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>Y(CH<sub>2</sub>CH<sub>3</sub>), Including Activation of Methane
作者:Matthew R. MacDonald、Ryan R. Langeslay、Joseph W. Ziller、William J. Evans
DOI:10.1021/jacs.5b08597
日期:2015.11.25
(C5Me5)(2)Y(mu-Ph)(2)BPh2, 1, reacted with ethyllithium at -15 degrees C to make (C5Me5)(2)Y(CH2CH3), 2, which is thermally unstable at room temperature and formed the C-H bond activation product, (C5Me5)(2)Y(mu-H)(mu-eta(1):eta(5)-CH2C5Me4)Y(C5Me5), 3, containing a metalated (C5Me5)(1-) ligand. Spectroscopic evidence for 2 was obtained at low temperature, and trapping experiments with (PrNC)-Pr-i-(NPr)-Pr-i and CO2 gave the Y-CH2CH3 insertion products, (C5Me5)(2)Y-[(PrNC)-Pr-i(Et)(NPr)-Pr-i-kappa N-2,N'], 4, and [(C5Me5)(2)Y(mu-O2CEt)](2), 5. Although 2 is highly reactive, low temperature isolation methods allowed the isolation of single crystals which revealed an 82.6(2)degrees Y-CH2-CH3 bond angle consistent with an agostic structure in the solid state. Complex 2 reacted with benzene and toluene to make (C5Me5)(2)YPh, 7, and (C5Me5)(2)YCH2Ph, 8, respectively. The reaction of 2 with [(C5Me5)(2)YCl](2) formed (C5Me5)(2)Y(mu-Cl)(mu-eta(1):eta(5)-CH2C5Me4)Y(C5Me5) in which a (C5Me5)(1-) ligand was metalated. C-H bond activation also occurred with methane which reacted with 2 to make [(C5Me5)(2)YMe](2), 9.
(C5Me5)(2)Y(mu-Ph)(2)BPh2, 1,与乙基锂在-15°C下反应生成(C5Me5)(2)Y(CH2CH3), 2。该化合物在室温下热力学不稳定,并形成了C-H键活化产物(C5Me5)(2)Y(mu-H)(mu-eta(1):eta(5)-CH2C5Me4)Y(C5Me5), 3,其中含有一个金属化的(C5Me5)(1-)配体。通过低温下的光谱分析获得了2的证据,并与(PrNC)-Pr-i-(NPr)-Pr-i和CO2进行捕捉实验,得到了Y-CH2CH3插入产物:(C5Me5)(2)Y-[(PrNC)-Pr-i(Et)(NPr)-Pr-i-kappa N-2,N'], 4,和[(C5Me5)(2)Y(mu-O2CEt)](2), 5。尽管2具有高度反应性,但低温分离方法允许分离出单晶,揭示了一个82.6(2)度的Y-CH2-CH3键角,这与固体状态下的agostic结构一致。2与苯和甲苯反应分别生成(C5Me5)(2)YPh, 7,和(C5Me5)(2)YCH2Ph, 8。2与[(C5Me5)(2)YCl](2)反应生成(C5Me5)(2)Y(mu-Cl)(mu-eta(1):eta(5)-CH2C5Me4)Y(C5Me5),其中(C5Me5)(1-)配体被金属化。甲烷的C-H键活化也与2反应,生成[(C5Me5)(2)YMe](2), 9。