Copper Nanoparticles Catalyzed Se(Te)Se(Te) Bond Activation: A Straightforward Route Towards Unsymmetrical Organochalcogenides from Boronic Acids

Abstract

A highly porous copper metal-organic framework, [Cu 3 (BTC) 2 ] (BTC = benzene-1,3,5-tricarboxylate) was synthesized and used as a precursor for the synthesis of copper nanoparticles (NPs) and characterized by several techniques, including XRD, SEM, TEM, EDX and BET measurements. The as-synthesized copper nanoparticles were immobilized onto activated charcoal (AC) by means of ultrasonication at room temperature without any pretreatment. The Cu NPs/AC was employed as a heterogeneous catalyst for the cross-coupling of diphenyl diselenide and boronic acids to form diphenyl selenides through SeÀSe bond activation under ligand-, base-, and additive-free conditions. The copper NPs/AC, which combines the architecture of MOFs and the high surface area of charcoal, could be an efficient heterogeneous catalytic system that is compatible with a variety of substituents on diphenyl selenides. Its promising catalytic activity relative to that of other homogeneous systems and low catalyst loading for the synthesis of unsymmetrical diaryl selenides is an important application in the area of nanocatalysis. The Cu NPs/AC catalyst, which exhibits excellent catalytic activity and remarkable tolerance to a wide variety of substituents, led to Se sp 3 -, sp 2 -, and sp-carbon bond formation by using DMSO as a solvent and atmospheric air as oxidant. This approach can also be extended to the preparation of unsymmetrical organotelluride derivatives.Copper catalysts for cross-coupling reactions are an intense field of research because they are cost-effective and hold promise for the replacement of expensive metal sources for industrial purposes. Over the past decade, the construction of carbonÀselenium bonds has been an intriguing topic for researchers and the number of related publications has increased exponentially to date, mainly owing to the important therapeutic characteristics of these bonds, such as their antimicrobial, antiviral, antitumor, and antioxidant properties. In addition, chalcogens are important constituents of functional groups in biomolecules (i.e., those associated with redox chemistry) in eukaryotic biochemistry.[1] Moreover, seleniumbased ionic liquids have proven to be efficient catalysts in reactions such as the carbonylation of aniline, oxidation of thiols, syntheses of octahydroacridines and thioacetals, and the Baylis-Hillman reaction of aldehydes and electron-deficient alkenes. [2][3][4][5][6][7] Over the past decade, extensive work has been devoted to developing new methodologies for the creation of bonds between sp 3 -, sp 2 -, sp-carbon atoms and organochalcogens, especially selenium-and tellurium-based compounds. To synthesize these moieties, a number of synthetic methods have been reported so far. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Of these, two methods are generally used. These methods involve the use of diphenyl diselenide (telluride) as starting precursor owing to its stability in air, environmental friendliness, and commercial availability. Diphenyl diselenide can be reacted w...

Copper-catalyzed direct C–H arylselenation of 4-nitro-pyrazoles and other heterocycles with selenium powder and aryl iodides. Access to unsymmetrical heteroaryl selenides

“…Structures bearing pyridine and thiophen moieties at selenium are available by previously mentioned methods from diselenides. [53][54][55] Special attention should be paid to those reagents in the context of unsymmetrical heteroaryl selenides' synthesis. In a recent review, Arsenyan summarizes the progress in this matter, listing all the possible synthetic pathways to obtain aryl-Se-heteroaryl compounds (bearing a variety of pharmacophores) from diaryl diselenides.…”

Nanocatalysts for C–Se cross-coupling reactions

“…The reaction was run in DMSO and gave good to quantitative yields (61-100%). 34 In 2014, Bhaumik and Islam along with their co-workers designed a novel reusable and non-leaching organo-copper catalyst (Cu II -CIN-1), based on loading of bivalent Cu(II) over the surface of a nitrogen-rich porous covalent imine network material (CIN-1). This novel heterogeneous copper catalyst was successfully used for the synthesis of a series of organoselenides 16 via C-Se bond forming cross-coupling reaction between aryl boronic acids 15 and diphenyl diselenide 2 in PEG-600.…”

Assembly of ZnIIand CdIIcoordination polymers with different dimensionalities based on the semi-flexible 3-(1H-benzimidazol-2-yl)propanoic acid ligand

“…The structures of coordination polymers are strongly influenced by the organic ligands and metal ions and it is important to choose suitable ligands and metal ions under appropriate synthetic conditions to synthesize coordination complexes with interesting structures. The exploration of metal-organic frameworks (MOFs) have received much attention because of their intriguing architectures and wide range of potential applications in different fields (Castellanos et al, 2016;Zhang et al, 2016;Kumar et al, 2015;Liu et al, 2016;Mü ller-Buschbaum et al, 2015;Duerinck & Denayer, 2015;Mohan et al, 2015). The assembly of Zn II (Jurcic et al, 2015;Karmakar et al, 2016a,b;Liang et al, 2016;Wannapaiboon et al, 2015;Ying et al, 2015) and Cd II (Xiao et al, 2015, Wu et al, 2011, Hu et al, 2015, Cao et al, 2014, Zhang et al, 2015 ions with multidentate nitrogen-containing ligands has produced various MOFs with fascinating structures and luminescent properties.…”