Mechanisms and models for homogeneous copper mediated ligand exchange reactions of the type: CuNu + ArX → ArNu + CuX

Couture, Christiane; Paine, Anthony J.

doi:10.1139/v85-019

Cited by 64 publications

(23 citation statements)

References 14 publications

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“…However, the greater dependence of the reaction rates on the identity of the halogen than on the reduction potential of the haloarene provides some evidence against a mechanism initiated by electron transfer to the type of π-arene complex proposed in previous work 20,45…”

Section: Resultsmentioning

confidence: 84%

“…In the mid 1980s, Paine reported mechanistic data on C–N coupling reactions catalyzed by “ligandless” copper(I) 20,45. This author suggested that the C–X cleavage of aryl halides by copper(I) catalysts proceeds by binding of Cu to the π system of the haloarene to form an η 2 -arene complex, followed by electron transfer to the arene and dissociation of iodide.…”

Section: Resultsmentioning

confidence: 99%

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Copper Complexes of Anionic Nitrogen Ligands in the Amidation and Imidation of Aryl Halides

et al. 2008

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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 L 2 Cu + cation and a CuX 2 − anion. A tetraalkylammonium salt of the CuX 2 − anion in which X = phthalimidate was also isolated. Conductivity measurements and 1 H 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) 2 Cu][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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Section: Resultsmentioning

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Copper Complexes of Anionic Nitrogen Ligands in the Amidation and Imidation of Aryl Halides

et al. 2008

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“…The ortho-carboxylate group has been known to effectively accelerate homogeneous copper-catalyzed exchange reactions. [13] Accordingly, a possible mechanism of formation of N-alkylanthranilic acids is proposed in Scheme 2 according to the results above. Reaction of the substituted 2-halobenzoic acid with K 3 PO 4 afforded the corresponding potassium benzoate (I), and treatment of I with CuI forms complex II.…”

Section: Resultsmentioning

confidence: 99%

“…The orthocarboxylate group has been known to effectively accelerate homogeneous copper-catalyzed exchange reactions. [13] Accordingly, a possible mechanism of formation of N-alkylanthranilic acids is proposed in …”

Section: Full Papersmentioning

confidence: 99%

Efficient Copper‐Catalyzed Synthesis of N‐Alkylanthranilic Acids via an ortho‐Substituent Effect of the Carboxyl Group of 2‐Halobenzoic Acids at Room Temperature

Zeng¹,

Fu²,

Qiao³

et al. 2009

Adv Synth Catal

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Abstract:We have developed an efficient copper-catalyzed method for the synthesis of N-alkylanthranilic acids. The protocol uses inexpensive copper(I) iodide/racemic 1,1'-binaphthyl-2,2'-diol (rac-BINOL) as the catalyst/ligand system, readily available 2-haloA C H T U N G T R E N N U N G benzoic acids and aliphatic amines as the starting materials, the coupling reactions were performed at room temperature, and various functionalities in the substrates were tolerated.

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“…Thankfully, this reaction has been modified and improved over the last century, and now modern variants of the Ullman‐type reaction not only serve for C–C bond formation but also for C–N, C–O, C–S, and some other bond formations . Moreover, some investigations have revealed that the efficiency of arylation could be greatly improved by the presence of suitable ligands in the copper‐catalysed systems . Special copper/ligand systems with a catalytic amount of copper could achieve the formation of C–C, C–N, and C–O bonds under much milder conditions .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of an anthraquinonoid disperse reactive dye based on a ligand‐free Ullmann reaction

Zhang

Sun

et al. 2017

Coloration Technology

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A new anthraquinonoid disperse reactive dye containing a dichlorotriazine reactive group was successfully synthesised on the basis of the Ullmann reaction in a ligand-free system by employing a copper(I) iodide as catalyst, in combination with a subsequent condensation reaction. The parameters of the cross-coupling reaction between 1-chloroanthraquinone and 2,5-diaminotoluene sulphate were investigated and optimised, such as the molar ratio of the reactants, the dosage of potassium carbonate and copper(I) iodide, the reaction temperature, and the reaction time. The results demonstrate that the dosage of potassium carbonate and the reaction time had significant impacts on the yield of the dye precursor, and an optimum synthesis process was also recommended. Moreover, the achieved dye was successfully characterised and confirmed from chemical structure and colour characteristics by employing Fourier transform infrared analysis, nuclear magnetic resonance spectroscopy, UV-vis absorption spectroscopy, elemental analysis, and liquid chromatography-mass spectrometry (LC-MS). Furthermore, a successful application of the obtained dye was achieved, with satisfactory coloration properties on silk and wool. Coloration Technology Society of Dyers and Colourists

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Mechanisms and models for homogeneous copper mediated ligand exchange reactions of the type: CuNu + ArX → ArNu + CuX

Cited by 64 publications

References 14 publications

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

Efficient Copper‐Catalyzed Synthesis of N‐Alkylanthranilic Acids via an ortho‐Substituent Effect of the Carboxyl Group of 2‐Halobenzoic Acids at Room Temperature

Synthesis of an anthraquinonoid disperse reactive dye based on a ligand‐free Ullmann reaction

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