Phosphine-bound zinc halide complexes for the coupling reaction of ethylene oxide and carbon dioxide
Phosphine-bound zinc halide complexes for the coupling reaction of ethylene oxide and carbon dioxide
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DOI：
10.1016/j.jcat.2005.01.033
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发表时间：
2005-05-15
影响因子：
7.3
通讯作者：
Lee, SH
中科院分区：
文献类型：
--
作者：
Kim, HS;Bae, JY;Lee, SH
由卤化锌(II)与两个当量的膦反应得到的卤化锌膦加成物--锌(II)的膦加合物--锌(Ⅱ)与环氧乙烷的偶联反应生成碳酸乙二酯，表现出较高的催化活性。除ZnX2(PCy3)(2)外，其催化活性几乎不受膦配体亲核性的影响，而与卤化物配体的性质密切相关。分离得到了一个含乙氧基膦配体的活性物种--Zn3Br6[Mu-OCH2CH2-P(C6H5)(3)](3)，并用X-射线单晶衍射、元素分析和核磁共振光谱对其结构进行了表征。讨论了活性物种和环状碳酸盐形成的机理途径。(C)2005 Elsevier Inc.保留所有权利。
Phosphine adducts of zinc(II) halides, ZnX2L2 (X = Cl, Br, 1; L = PMe2Ph, PEt3, PBu3, PPh3, PCy3), prepared by the reaction of ZnX2 with two equivalents of corresponding phosphines, showed high activities for the coupling reaction Of CO2 and ethylene oxide to produce ethylene carbonate. The catalytic activity of ZnX2L2 was hardly affected by the nucleophilicity of the phosphine ligands, with the exception of ZnX2(PCy3)(2), but depended strongly on the nature of halide ligands. An active species containing ethoxyphosphonium ligands, Zn3Br6[mu-OCH2CH2-P(C6H5)(3)](3), was isolated and characterized by X-ray crystallography, elemental analysis, and NMR spectroscopy. The mechanistic pathway for the formation of active species and cyclic carbonates is discussed. (c) 2005 Elsevier Inc. All rights reserved.