Quantification of theβ-Stabilizing Effect of the Dicarbonyl(η5-cyclopentadienyl)iron Group
作者:Felix Dulich、Karl-Heinz Müller、Armin R. Ofial、Herbert Mayr
DOI:10.1002/hlca.200590137
日期:2005.7
investigations of the reactions of (prop-2-enyl)dicarbonyl(cyclopentadienyl)iron complexes 1 with benzhydrylium ions 3, and of dicarbonyl(cyclopentadienyl)[(1,2-η)propene]iron(II) tetrafluoroborate (9⋅BF4) with π-nucleophiles have been performed to elucidate the magnitude of the β-effect of the [(CO)2FeCp] group (Fp group). Introduction of the Fp group into the allylic position of propene and 2-methylpropene
的(丙-2-烯基)二羰基(环戊二烯基)铁配合物的反应的动力学研究1与benzhydrylium离子3,和二羰基(环戊二烯基)[(1,2-的η)丙烯]铁(II)四氟硼酸盐(9 ⋅BF 4)已经用π-亲核试剂来阐明[(CO)2 FeCp]基团(Fp基团)的β-效应的大小。将Fp基团引入丙烯和2-甲基丙烯的烯丙基位置可将π键的亲核性分别提高9个和6个数量级,其结果是烯丙基-Fp络合物1a(N= 6.78)和1b(N = 8.45)是最强的中性π-亲核试剂。Fp基团取代异丙基阳离子中的一个β -H原子会使亲电性降低20个数量级以上,因此9 +在最弱的阳离子C-亲电体中排名(E = -11.2)。