Environmentally Friendly and Recyclable CuCl2-Mediated C–S Bond Coupling Strategy Using DMEDA as Ligand, Base, and Solvent

Abstract

Simple reaction conditions and recyclable reagents are an irreplaceable advantage for environmentally friendly industrial applications. An environment friendly, recyclable and economic strategy was developed to synthesize diaryl chalcogenides by the CuCl2 catalyzed C-S bond formation reaction via iodobenzenes and benzenethiols/1,2-diphenyldisulfanes using N,N’-dimethylethane-1,2-diamine (DMEDA) as ligand, base and solvent. For these reactions, especially the reactions of diiodobenzenes and aminobenzenethiols/disulfanediyldianilines, a range of substrates is compatible to give the corresponding products in good to excellent yields. Both the reaction reagents of the catalytic system (CuCl2/DMEDA) are inexpensive, conveniently separable and recyclable for more than 5 cycles.

Evaluating Diazene to N2 Interconversion at Iron‐Sulfur Complexes

“…Therefore, we used a more recently developed copper-catalyzed aryl CÀ S coupling method, which led to the dianiline intermediate in 49 % yield on a 20 g scale. [27] The dianiline was then converted to the dithiol using Sellmann's method, and the dithiol was deprotonated with lithium methoxide to form the lithium dithiolate. [17c] Next, the free ligand was metalated with iron(II) chloride followed by the addition of PPr 3 .…”

Preparation of 2,5‐Disubstituted Tetrazoles using a Copper‐Catalysed Regioselective Direct Coupling of Tetrazoles with Free NH Groups and Boronic Acid Derivatives

“…These ligands help in preventing copper aggregation, enhancing solubility, stimulate milder conditions and stabilise active catalyst species during the catalysis process. [43,44] Later in 2016, Phukan and co-workers reported a facile Chan-Lam reactions designing [Cu(DMAP) 4 I]I as an excellent catalytic system. Other ligand based copper catalytic system, such as Cu(II)-salen complexes were also found to be effective for various CÀ N bond transformations.…”

“…Several coordinating ligands, such as N,N′‐ dimethylethylenediamine (DMEDA)and N,N,N′,N′ ‐tetramethylethylenediamine (TMEDA), [33] pyridine N ‐oxide, [34] thiophene‐2‐carboxylate (TC), [35] 1,10‐phenanthroline (phen) [36] and 4‐(Dimethylamino)pyridine (DMAP), [37–39] have been found promoting various copper catalysed C−N bond forming [40–42] reactions. These ligands help in preventing copper aggregation, enhancing solubility, stimulate milder conditions and stabilise active catalyst species during the catalysis process [43,44] . Later in 2016, Phukan and co‐workers reported a facile Chan‐Lam reactions designing [Cu(DMAP) 4 I]I as an excellent catalytic system.…”

Cascade Nucleophilic Attack/Addition Cyclization Reactions to Synthesize Oxazolidin-2-imines via (Z)-2-Bromo-3-phenylprop-2-en-1-ols/3-phenylprop-2-yn-1-ols and Diphenyl Carbodiimides

“…Recently, the oxazolidin-2-imines were synthesized by an intermolecular annulation reaction of 3-aminooxetanes with isocyanates by Sun et al Although the above reactions could form the 1,3-oxazolidines efficiently, these protocols usually require noble metal catalysts and some other additives. As our continuing effort, here we describe two new and direct nucleophilic attack/addition cyclization reactions, which provide economic and efficient one-pot cascade transformations to synthesize oxazolidin-2-imines under catalyst-free conditions by ( Z )-2-bromo-3-phenylprop-2-en-1-ols/3-phenylprop-2-yn-1-ols with diphenyl carbodiimides. We also reported a convenient strategy to synthesize 3-phenylprop-2-yn-1-ols by ( Z )-2-bromo-3-phenylprop-2-en-1-ols under the reaction conditions.…”