Butterfly‐Like Tetranuclear Copper(I) Clusters for Efficient Alkyne Homocoupling Reactions

Abstract

In this work, we here prepare a new tetranuclear Cu I cluster with a precise configuration of Cu 4 (PPh 3) 4 (bis(prop-2-ynyloxy) biphenyl) 2. X-ray single-crystal diffraction shows that the bialkynyl ligands bind to two Cu atoms via a σ-bond and to the other two Cu atoms via a π-bond configuration, presenting a new alkynyl-Cu motif and a butterfly-like framework. Cu 4 (PPh 3) 4 L 2 clusters exhibit photoluminescence property at 410 and 505 nm. Cu 4 (PPh 3) 4 L 2 clusters also give good performances in the alkyne homocoupling reactions after its immobilization on different oxides. The copper(I) species is proved to be the catalytic active site during the homocoupling reactions. And the basic property of the oxides (e. g. NiO) can promote the coupling catalysis, and a side-group effect of the alkyne reactants is distinctly observed. In all, this study extends the catalytic application of the copper clusters to the carbon-carbon coupling reactions and gives some cue to develop the potential exploitation of copper clusters in other organic transformations.

Copper‐Bridged Tetrakis(4‐ethynylphenyl)ethene Aggregates with Photo‐Regulated 1O2 and O2.− Generation for Selective Photocatalytic Aerobic Oxidation

“…In addition, in the infrared (IR) spectra (Figure S8), the disappearance of the hydrogen alkyne (3271 cm À 1 ) and the appearance of the CuÀ C�C peak (1915 cm À 1 ) further confirmed the formation of the T 4 EPE-Cu coordination polymer. [39] Nitrogen adsorption-desorption isotherms reflect the change of the specific surface area of a material. The Brunauer-Emmett-Teller (BET) surface area of T 4 EPE-Cu was approximately 136 m 2 g À 1 , which was 5.4 times higher than that of T 4 EPE (25 m 2 g À 1 ) (Figure 1f), which implies that there is improved specific surface area for T 4 EPE-Cu.…”

Unsymmetrical Naphthyridine-Based Dicopper(I) Complexes: Synthesis, Stability, and Carbon–Hydrogen Bond Activations

“…This problem was fixed by Hay in 1962 with the use of a bidentate ligand to stabilize the copper complexes. 67 The Glaser-Hay reaction [68][69][70][71][72][73][74] is a good example of a green reaction as it is done under mild reaction conditions, uses no hazardous nor toxic reagents and provides diynes in excellent yield with water as the only side product. As this reaction only need terminal alkynes in presence of copper (I), the Glaser-Hay reaction often yields side products in the other reactions shown in There are two main types of cycloadditions with alkynyl-copper complexes and they both involve 1,3 dipoles to form either 4-membered ring (Kinugasa reaction) or 5-membered ring products (Figure I.9b and c).…”

Recent Advances in Aerobic Photo-Oxidation over Small-Sized IB Metal Nanoparticles

“…In recent decades, well-defined IB metal nanoclusters (NCs) have been documented as novel and promising model catalysts owing to their unique electronic configuration [1][2][3][4][5]. For example, Au/Ag NCs show intrinsically different catalytic behaviors in comparison with conventional gold or silver nanoparticles (Au/Ag NPs) [6][7][8][9][10], which results in superior catalytic properties in many organic reactions, such as selective oxidation and hydrogenation and carbon-carbon couplings.…”