Cationic Zirconium Dialkyl and Alkyl Complexes Supported by DAC (Deprotonated 4,13-Diaza-18-crown-6) Ligation
作者:Lawrence Lee、David J. Berg、Gordon W. Bushnell
DOI:10.1021/om961027n
日期:1997.6.1
trans-1a. Reaction of Zr(CH2Ph)2Cl2 with H2DAC, followed by treatment with LiR (2 equiv), gives cis-Zr(DAC)R2 (R = CH2SiMe3, cis-1b; R = CH2CMe3, cis-1c) exclusively. Alkyl abstraction from cis- or trans-1a using B(C6F5)3 (1 equiv) produces the stable cation [Zr(DAC)(CH2Ph)]+[B(CH2Ph)(C6F5)3]- (2a) as a yellow oil. NMR studies on 2a in CD2Cl2 show no evidence for η2-benzyl formation or anion coordination.
报道了由DAC(去质子化的4,13-diaza-18-crown-6)连接支持的一系列中性和阳离子Zr烷基的合成,表征和反应性。H 2 DAC与Zr(CH 2 Ph)4的反应得到顺式-和反式-Zr(DAC)(CH 2 Ph)2(顺式/反式-1a)的1:4混合物。纯异构体在溶液中经历缓慢的顺-反异构化,以再生1:4的顺:反平衡混合物。X射线晶体学的结果汇报了顺式-和反式- 1A。Zr(CH 2 Ph)2 Cl 2与H 2 DAC反应,然后用LiR(2当量)处理,得到顺式-Zr(DAC)R 2(R = CH 2 SiMe 3,顺式-1b ; R = CH 2 CME 3,顺式- 1C)独占。使用B(C 6 F 5)3(1当量)从顺式或反式-1a烷基提取产生稳定的阳离子[Zr(DAC)(CH 2 Ph)] + [B(CH 2Ph)(C 6 F 5)3 ] -(2a)为黄色油。核磁共振研究2A在CD