Polynuclear complexes of copper(I) halides: coordination chemistry and catalytic transformations of alkynes

Immobilization of Porphyrinatocopper Nanoparticles onto Activated Multi‐Walled Carbon Nanotubes and a Study of its Catalytic Activity as an Efficient Heterogeneous Catalyst for a Click Approach to the Three‐Component Synthesis of 1,2,3‐Triazoles in Water

“…As another validation for the formation of intermediate I, encouraged by previous reports, [88,89] phenylacetylene and CuTPP were mixed in a separate experiment in aqueous media, while the pH of water as solvent was monitored. A 0.7 unit decrease in pH after 10 min was detected, indicative of terminal proton release to the water due to the initial coordination of acetylide to porphyrinatocopper to form intermediate I (Scheme 6).…”

New Reactions of Copper Acetylides: Catalytic Dipolar Cycloadditions and Beyond

“…In many cases, amines are labeled as additives rather than ligands, since it is often the intention to aid in the deprotonation of the terminal alkyne rather than to coordinate to the metal center. However, this assumption is not accurate, as formation of copper (I) acetylides is so facile that it occurs even in strongly acidic media (up to 20-25% H 2 SO 4 ) [77]. Instead, the primary roles of amine ligands can be (i) to prevent the formation of unreactive polynuclear copper(I) acetylides; (ii) to facilitate the coordination of the azide to copper center at the ligand exchange step (vide infra); and (iii) to increase the solubility of the copper complex to deliver high solution concentrations of the necessary Cu(I)-species.…”

“…The chief complications are (i) the tendency of copper species to form polynuclear compounds [77,112] and (ii) the great facility of the ligand exchange at the copper center. As a result, mixtures of Cu(I), terminal alkynes, and other ligands (including solvents) usually contain multiple organocopper species in rapid equilibrium with each other.…”

Polymer “Clicking” by CuAAC Reactions

“…As kindly pointed out by one referee the complex nature of the Cu(I)halide-acetylene interaction and the structural diversity of the complexes have been described in an excellent review by Mykhalichko. [10] The non-catalyzed thermal version of the reaction, first described by Michael [11] and later investigated in detail by Huisgen, [1,2] has been reviewed in great detail and analyzed by Frontal Orbital -Perturbation theory by Lwowski. [12] The large effect of the Cu(I) catalysis on this reaction can be attributed to the unpolar nature [13] of the reacting partners in the absence of Cu(I) providing a high barrier of activation energy, in combination with a large DG of the reaction.…”