Copper complexes of anionic nitrogen ligands in the amidation and imidation of aryl halides.
Copper complexes of anionic nitrogen ligands in the amidation and imidation of aryl halides.
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DOI：
10.1021/ja076668w
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发表时间：
2008-07-30
影响因子：
15
通讯作者：
Hartwig, John F.
中科院分区：
文献类型：
--
作者：
Tye, Jesse W.;Weng, Zhiqiang;Johns, Adam M.;Incarvito, Christopher D.;Hartwig, John F.
本文合成了铜(I)咪酰铜和咪酰铜螯合N，N供体配体的配合物，并利用x射线衍射和详细的液相法对其进行了表征。在某些情况下，配合物在固态中采用中性的三坐标三角形平面结构，但在其他情况下，它们采用由L2Cu+阳离子和CuX2−阴离子组成的离子形式。还分离出了一种CuX2−阴离子的四烷基铵盐，其中X =邻苯二甲酸酯。两种配合物混合物的电导率测量和1H NMR谱均表明，配合物在DMSO和DMF溶液中主要以离子形式存在。一种配合物在极性较低的溶剂中可充分溶解，并在THF中采用一定程度的离子形式，在苯中主要采用中性形式。含氮配体的配合物与碘芳烃和溴芳烃反应生成C-N偶联产物，但与[Cu(phth)2]−的铵盐没有反应。与两种不同碘芳烃的化学计量和催化反应具有相似的选择性和更快的化学计量反应速率，这表明分离的酰胺和酰亚胺配合物是含N，N配体的铜配合物催化酰胺和亚胺与卤代芳烃反应的中间体。这些酰胺类和邻苯二甲酸酯与氯芳烃的反应要慢得多，包括具有比某些溴芳烃更有利的还原电位的氯芳烃，以及已知的氯与氯芳烃自由基阴离子的快速解离。o-（烯丙氧基）碘苯与[(phen)2Cu][Cu(pyrr)2]的反应产生了高收率的C-N偶联产物，并且没有检测到产生自由基的3-甲基-2,3-二氢苯并呋喃或3-亚甲基-2,3-二氢苯并呋喃的产物。这些数据和计算的反应势垒反驳了卤代芳烃与双配位阴离子铜反应的机制，以及从电子转移开始产生游离碘芳烃自由基阴离子的机制。相反，这些数据更符合金属配位球内碳卤素键裂解的机制。
Copper(I) imidate and amidate complexes of chelating N,N-donor ligands, which are proposed intermediates in copper-catalyzed amidations of aryl halides, have been synthesized and characterized by X-ray diffraction and detailed solution-phase methods. In some cases, the complexes adopt neutral, three-coordinate trigonal planar structures in the solid state, but in other cases they adopt an ionic form consisting of an L2Cu+ cation and a CuX2− anion. A tetraalkylammonium salt of the CuX2− anion in which X = phthalimidate was also isolated. Conductivity measurements and 1H NMR spectra of mixtures of two complexes all indicate that the complexes exist predominantly in the ionic form in DMSO and DMF solutions. One complex was sufficiently soluble for conductance measurements in less polar solvents and was shown to adopt some degree of the ionic form in THF and predominantly the neutral form in benzene. The complexes containing dative nitrogen ligands reacted with iodoarenes and bromoarenes to form products from C–N coupling, but the ammonium salt of [Cu(phth)2]− did not. Similar selectivities for stoichiometric and catalytic reactions with two different iodoarenes and faster rates for the stoichiometric reactions implied that the isolated amidate and imidate complexes are intermediates in the reactions of amides and imides with haloarenes catalyzed by copper complexes containing dative N,N ligands. These amidates and imidates reacted much more slowly with chloroarenes, including chloroarenes that possess more favorable reduction potentials than some bromoarenes and that are known to undergo fast dissociation of chloride from the chloroarene radical anion. The reaction of o-(allyloxy)iodobenzene with [(phen)2Cu][Cu(pyrr)2] results in formation of the C-N coupled product in high yield and no detectable amount of the 3-methyl-2,3-dihydrobenzofuran or 3-methylene-2,3-dihydrobenzofuran products that would be expected from a reaction that generated free radicals. These data and computed reaction barriers argue against mechanisms in which the haloarene reacts with a two-coordinate anionic copper species and mechanisms that start with electron transfer to generate a free iodoarene radical anion. Instead, these data are more consistent with mechanisms involving cleavage of the carbon–halogen bond within the coordination sphere of the metal.
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DOI：
10.1139/v85-019
发表时间：
1985-01-01
期刊：
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE
影响因子：
--
作者：
COUTURE, C;PAINE, AJ
通讯作者：
PAINE, AJ
影响因子：
2
作者：
de Lange, Ben;Lambers-Verstappen, Marielle H.;de Vries, Johannes G.
通讯作者：
de Vries, Johannes G.
影响因子：
--
作者：
Goldberg, I
通讯作者：
Goldberg, I
影响因子：
2.1
作者：
AALTEN, HL;VANKOTEN, G;SHELDON, RA
通讯作者：
SHELDON, RA
影响因子：
3.6
作者：
Goodbrand, HB;Hu, NX
通讯作者：
Hu, NX