作者:Catherine L. Boyd、Aldo E. Guiducci、Stuart R. Dubberley、Ben R. Tyrrell、Philip Mountford
DOI:10.1039/b207184c
日期:2002.11.12
Reactions of the lithiated pendant arm functionalised benzamidinates LiMe2NCH2CH2NC(Ph)NSiMe3} and LiMe2NCH2CH2CH2NC(Ph)NSiMe3} with the compounds [Ti(NR)Cl2(py)3]
(R =
tBu, 2,6-Me2C6H3, 2,6-iPr2C6H3) afforded five-coordinate [Ti(NR)Me2NCH2CH2NC(Ph)NSiMe3}Cl]
1–3 and [Ti(NR)Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
4–6, respectively. Reaction of [Ti(NtBu)Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
4 with C6F5NH2 gave elimination of tBuNH2 and the corresponding perfluoroarylimido complex 7. The X-ray crystal structures of [Ti(NtBu)Me2NCH2CH2NC(Ph)NSiMe3}Cl]
1 and [Ti(N-2,6-R2C6H3)Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
(R = Me 5 or iPr 6) have been determined. Reaction of either 1 or 4 with H2N-2,6-Me2C6H3 in C6D6 afforded the corresponding arylimido compounds 2 and 5, but this route is not amenable to easy scale-up. For better evaluation of the effects of the pendant NMe2 donor group in 1–6, the bis(pyridine) compound [Ti(NtBu)MeCH2CH2NC(Ph)NSiMe3}Cl(py)2]
9 was prepared from LiMeCH2CH2NC(Ph)NSiMe3}
8 and [Ti(NtBu)Cl2(py)3]. The compounds 1–3 with two-carbon pendant arms are quite sensitive to adventitious protonation, and the X-ray crystal structures of the products of two such reactions, namely [Ti2Me2NCH2CH2NC(Ph)N(H)SiMe3}2(NtBu)2Cl2(μ-Cl)2]
10 and [Ti2(N-2,6-C6H3Me2)2Cl2(μ-O)Me2NCH2CH2NC(Ph)N(H)SiMe3}2]
11, have been determined. Both possess amidine ligands that show interesting intramolecular N–H⋯X (X =
μ-Cl or μ-O) hydrogen bonds.
锂化侧臂功能化苯甲脒酯 LiMe2NCH2CH2NC(Ph)NSiMe3} 和 LiMe2NCH2CH2CH2NC(Ph)NSiMe3} 与化合物 [Ti(NR)Cl2(py)3] 的反应
(R =
tBu, 2,6-Me2C6H3, 2,6-iPr2C6H3) 提供五配位 [Ti(NR)Me2NCH2CH2NC(Ph)NSiMe3}Cl]
1–3 和 [Ti(NR)Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
分别为 4-6。 [Ti(NtBu)Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]的反应
4 与 C6F5NH2 消除 tBuNH2 和相应的全氟芳基亚氨基络合物 7. [Ti(NtBu)Me2NCH2CH2NC(Ph)NSiMe3}Cl] 的 X 射线晶体结构
1和[Ti(N-2,6-R2C6H3)Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
(R = Me 5 或 iPr 6) 已确定。 1或4与C6D6中的H2N-2,6-Me2C6H3反应得到相应的芳基酰亚氨基化合物2和5,但该路线不易于放大。为了更好地评估 1-6 中 NMe2 供体侧基的影响,使用双(吡啶)化合物 [Ti(NtBu)MeCH2CH2NC(Ph)NSiMe3}Cl(py)2]
9由LiMeCH2CH2NC(Ph)NSiMe3}制备
8和[Ti(NtBu)Cl2(py)3]。具有双碳侧臂的化合物1-3对偶然的质子化非常敏感,并且两个此类反应的产物的X射线晶体结构,即[Ti2Me2NCH2CH2NC(Ph)N(H)SiMe3}2(NtBu) )2Cl2(μ-Cl)2]
10 和 [Ti2(N-2,6-C6H3Me2)2Cl2(μ-O)Me2NCH2CH2NC(Ph)N(H)SiMe3}2]
11、已确定。两者都具有脒配体,显示出有趣的分子内 N–H⋯X (X =
μ-Cl或μ-O)氢键。