Cyclopentadiene Alkylation and Nickel Complexes with Tri-, Tetra-, or Pentaisopropylcyclopentadienide or an Even Bulkier Lithium Alkylcyclopentadienide
作者:Daniel Weismann、Dirk Saurenz、Roland Boese、Dieter Bläser、Gotthelf Wolmershäuser、Yu Sun、Helmut Sitzmann
DOI:10.1021/om200372j
日期:2011.12.12
respectively. The triphenylphosphine derivative 10 displays a dissociation equilibrium with small amounts of 9 in deuteriobenzene solution and could be converted to the methylnickel(II) derivative [(C5iPr4H)NiMe(PPh3)] (11) or to the phenyl complex [(C5iPr4H)NiPh(PPh3)] (12), respectively. Substitution reactions of the bromide 9 yielded a dinuclear complex with two bridging 2,6-dimethylphenolate ligands, [(C5iPr4H)Ni(μ-2
相转移催化已经适合于以高收率和高纯度合成三异丙基环戊二烯异构体1。已显示三异丙基环戊二烯酸钠与异丙基溴在四氢呋喃中的烷基化反应是目前最有效的生成四异丙基环戊二烯异构体2的方法,该异构体在金属化后可得到四异丙基环戊二烯酸钠(3)。引入第五个异丙基的关键步骤是,亚胺盐选择性攻击5位的四异丙基环戊二烯阴离子,并生成相应的1,2,3,4-四异丙基(6-二甲基氨基)富勒烯(4),已按照公开的程序进行。将1-萘基锂加到二甲基氨基富勒烯4中,产生非常庞大的二甲基氨基(1-萘基)甲基四异丙基环戊二烯化锂(7)。由三异丙基环戊二烯酸钠和溴化镍(II)获得纯的1,2,4,1',2',4'-六异丙基镍茂(8)。四异丙基环戊二烯基镍(II)溴化物[(C 5 i Pr 4 H)Ni(μ-Br)] 2(9)加入三苯基膦,三甲基膦,亚磷酸三甲酯和三异丙基膦,并形成反磁性膦络合物[(C 5 i Pr 4H)NiBr(PPh