Novel Lanthanide Amides Incorporating Neutral Pyrrole Ligand in a Constrained Geometry Architecture: Synthesis, Characterization, Reaction, and Catalytic Activity
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- 作者：Fenhua Wang ; Shaowu Wang ; Xiancui Zhu ; Shuangliu Zhou ; Hui Miao ; Xiaoxia Gu ; Yun Wei ; Qingbing Yuan
- 刊名：Organometallics
- 出版年：2013
- 出版时间：July 22, 2013
- 年：2013
- 卷：32
- 期：14
- 页码：3920-3931
- 全文大小：613K
- 年卷期：v.32,no.14(July 22, 2013)
- ISSN：1520-6041
文摘
The first series of lanthanide amido complexes incorporating a neutral pyrrole ligand in a constrained geometry architecture were synthesized, and their bonding, reactions, and catalytic activities were studied. Treatment of [(Me3Si)2N]3Ln(渭-Cl)Li(THF)3 with 1 equiv of (N-C6H5NHCH2CH2)(2,5-Me2C4H2N) (1) afforded the first example of bisamido lanthanide complexes having the neutral pyrrole 畏5-bonded to the metal formulated as [畏5:畏1-(N-C6H5NCH2CH2)(2,5-Me2C4H2N)]Ln[N(SiMe3)2]2 (Ln = La (2) and Nd (3)). Reaction of [(Me3Si)2N]3Sm(渭-Cl)Li(THF)3 with 2 equiv of 1 produced the complex [畏5:畏1-(N-C6H5NCH2CH2)(2,5-Me2C4H2N)][畏1-(N-C6H5NCH2CH2)(2,5-Me2C4H2N)]]SmN(SiMe3)2 (4). Treatment of 3 with 2 equiv of 1 gave the sandwich neodymium complex [畏5:畏1-(N-C6H5NCH2CH2)(2,5-Me2C4H2N)]2Nd[畏1-(N-C6H5NCH2CH2)(2,5-Me2C4H2N)] (5), in which two neutral pyrroles bonded with metal in an 畏5 mode. Complex 5 could also be prepared by reaction of [(Me3Si)2N]3Nd(渭-Cl)Li(THF)3 with 3 equiv of 1. Reactivities of the lanthanide bisamido complexes were further investigated. Reaction of complex 2 with pyrrolyl-functionalized imine [2-(2,6-iPr2C6H3N鈺怌H)C4H3NH] afforded a mixed 畏5-bonded neutral pyrrole and 畏1-bonded anionic pyrrolyl lanthanum complex [畏5:畏1-(N-C6H5NCH2CH2)(2,5-Me2C4H2N)]{畏1-2-[(2,6-iPr2C6H3)NCH]C4H3N}La[N(SiMe3)2] (6). Reactions of complexes 2 and 3 with pyrrolyl-functionalized secondary amine afforded the mixed 畏5-bonded neutral pyrrole and the 畏1-bonded anionic pyrrolyl lanthanide complexes [畏5:畏1-(N-C6H5NCH2CH2)(2,5-Me2C4H2N)][(畏1-2-tBuNCH)C4H3N]2Ln (Ln = La (7), Nd (8)) with dehydrogenation of the secondary amine. Investigation of the catalytic properties of complexes 2鈥?b>8 indicated that all complexes exhibited a high activity with a high chemo- and regioselectivity on the addition of dialkyl phosphite to 伪,尾-unsaturated carbonyl derivatives. An interesting result was found that 1,2-hydrophosphonylation substrates could be catalytically converted to 1,4-hydrophosphinylation products when the substrates are the substituted benzylideneacetones by controlling the reaction conditions.