Benzotriazole: an efficient ligand for the copper-catalyzed N-arylation of indoles

A general, efficient, and inexpensive method for the N-arylation of indoles using a catalytic system derived from CuI and benzotriazole is reported. Selective mono N-arylation of indoles with ortho-dihaloarenes has also been successfully achieved in good yields using this protocol.     

4,7-Dimethoxy-1,10-phenanthroline: an excellent ligand for the Cu-catalyzed N-arylation of imidazoles

[reaction: see text] 4,7-Dimethoxy-1,10-phenanthroline (L) was found to be an efficient ligand for the copper-catalyzed N-arylation of imidazole with aryl iodides and bromides under mild conditions. A variety of hindered and functionalized imidazoles and aryl halides were transformed in good to excellent yields.     

Ninhydrin: an efficient ligand for the Cu-catalyzed N-arylation of nitrogen-containing heterocycles with aryl halides

Cu₂O/ninhydrin was found to be an efficient catalyst system for the N-arylation of nitrogen-containing heterocycles with aryl and heteroaryl iodides, bromides and even unactivated chlorides to give the products in moderate to excellent yields.     

Tetrazole-1-acetic acid as a ligand for copper-catalyzed N-arylation of imidazoles with aryl iodides under mild conditions

Tetrazole-1-acetic acid was found to serve as a superior ligand for CuI-catalyzed N-arylation of imidazoles with aryl iodides under a low catalyst loading (5 mol% of CuI). A variety of aryl iodides could be aminated to provide the N-arylated products in good to excellent yields without the need of an inert atmosphere.     

2-aminopyrimidine-4,6-diol as an efficient ligand for solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides

Efficient and solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides have been demonstrated. In the presence of CuBr, 2-aminopyrimidine-4,6-diol, and TBAF (n-Bu4NF), a variety of imidazoles underwent the N-arylation reaction with aryl and heteroaryl halides smoothly in moderate to excellent yields. Noteworthy is that the reaction is conducted under solvent-free conditions.     

Simple copper salt-catalyzed N-arylation of nitrogen-containing heterocycles with aryl and heteroaryl halides

Relatively mild and highly efficient CuI-catalyzed N-arylation procedures for nitrogen-containing heterocycles (e.g., imidazoles, benzimidazoles, pyrroles, pyrazoles, indoles, triazoles, etc.) with aryl and heteroaryl halides have been developed. The protocols can be performed easily and tolerate a number of functional groups, such as ester, nitrile, nitro, ketone, free hydroxyl, and free primary amine on the aryl halide.     

Copper catalyzed N-arylation between aryl halides and nitriles in water: an efficient tandem synthesis of benzanilides

A series of benzanilide compounds were synthesized through copper-catalyzed tandem reactions. With the assistance of ionic liquid as phase transfer catalyst, aryl halides, and nitriles underwent a hydrolysis/coupling pathway to form benzanilides in water. Advantages of this reaction include the use of water as the environmental friendly solvent, short reaction time, and the tolerance of various functional groups. A proposed mechanism based on control experiments is also presented.     

Highly efficient copper-catalyzed N-arylation of nitrogen-containing heterocycles with aryl and heteroaryl halides

New (S)-pyrrolidinylmethylimidazole ligands (4a-c) have been readily synthesized in a straightforward fashion from least expensive starting materials in short steps in high yields. Relatively mild and highly efficient CuI-catalyzed N-arylation procedures for imidazoles with aryl and heteroaryl bromides or chlorides have been developed in the presence of 4a and Cs2CO3. It is important to note that the protocol could tolerate functional groups such as ester, nitrile, nitro, ketone, free hydroxyl, and free primary amine on the aryl halide. The protocol could also be applicable to other pi-electron-rich nitrogen heterocycles (pyrrole, pyrazole, indole, benzimidazole, and triazole), affording the N-arylazoles in good to excellent yields.     

A general and efficient CuI/BtH catalyzed coupling of aryl halides with thiols

We report an exceptionally mild, general and efficient copper catalyzed cross coupling reaction of aryl bromides and thiols using 0.5 mol % CuI and 1 mol % benzotriazole. Experimental simplicity, generality, functional group tolerance and low cost of the catalyst are advantages of the protocol.     

N-arylation of azaheterocycles with aryl and heteroaryl halides catalyzed by iminodiacetic acid resin-chelated copper complex

<正>Iminodiacetic acid resin-chelated copper(Ⅱ) complex is effective in cross-coupling reactions between azaheterocycles and aryl or heteroaryl halides,providing N-arylated products in good to excellent yields.The copper catalyst is air stable and can be readily recovered and reused with minimal loss of activity for three runs.     

β-Ketoimine as an efficient ligand for copper-catalyzed N-arylation of nitrogen-containing heterocycles with aryl halides

An efficient copper catalyst system, Cu₂O/β-ketoimine L₁, for the N-arylation of nitrogen-containing heterocycles with aryl iodides and bromides has been developed. The system works well with the electron-rich, -neutral, and -deficient aryl bromides to afford the products in good to excellent yields.     

Copper-catalyzed N-arylation of 2-arylindoles with aryl halides

10 mol% Cul combined with the DMEDA ligand can efficiently catalyze the N-arylation of 2-arylindoles with aryl iodides and aryl bromides in good to excellent yields. The aryl halides bearing electron-rich or electron-deficient functional groups can be well tolerated under this mild reaction conditions.     

Practical copper-catalyzed N-arylation of nitrogen heterocycles with aryl halides under ligand and additive free conditions

N-arylation of a wide variety of nitrogen heterocycles with aryl iodides catalyzed by copper iodide under mild ligand and additive free conditions (ⁿBu₄NBr, PhMe, NaOH, reflux, 22 h) was accomplished in good to excellent yields (up to 95%) and substrate conversions (up to 99%).     

Ligand-free copper nanoparticle promoted N-arylation of azoles with aryl and heteroaryl iodides

A relatively mild, efficient, and inexpensive method for the nucleophilic aromatic substitution of the N–H heterocycles with various aryl and heteroaryl iodides using copper nanoparticles (Cu-NP) is reported. The coupling reaction has been successfully achieved with moderate to good yields.     

Pyrrole-2-carboxylic acid as a ligand for the Cu-catalyzed reactions of primary anilines with aryl halides

Pyrrole 2-carboxylic acid (L5) was found to be an effective ligand for the Cu-catalyzed monoarylation of anilines with aryl iodides and bromides. Under the reported conditions (10% CuI/20% L5/DMSO/K3PO 4/80-100 degrees C/20-24 h), a variety of useful functional groups were tolerated, and moderate to good yields of the diaryl amine products were obtained.     

Coupling reactions of aryl and heteroaryl halides with a trimethylsilylethynylpyrazine

By the coupling reactions of trimethylsilylacetylene and 2-chloro-3,6-diisobutylpyrazine, 3,6-diisobutyl-2-trimethylsilylethynylpyrazine or 1,2-bis(3,6-diisobutylpyrazin-2-yl)acetylene was obtained, depending on the solvent used. The former substance coupled with various aryl and heteroaryl halides to give 1-aryl-2-pyrazin-ylacetylenes.     

Copper-catalyzed N-arylation of diazoles with aryl bromides using KF/Al2O3: an improved protocol

Copper-catalyzed N-arylation of diazoles can be accomplished using air-stable CuI as a copper source and 1,10-phenanthroline in the presence of KF/Al₂O₃ as a base. This is a simple and efficient method for the coupling of aryl bromide with diazoles. Different functionalized aryl bromides were coupled with diazoles using this system.     

Solvent-free copper-catalyzed N-arylation of amino alcohols and diamines with aryl halides

A simple and mild method for the coupling of aryl halides with amino alcohols and diamines is described. The reactions can be performed under ligand-free and solvent-free conditions, and generate the products in good yield.     

One-pot primary aminomethylation of aryl and heteroaryl halides with sodium phthalimidomethyltrifluoroborate

A one-pot primary aminomethylation of aryl halides, triflates, mesylates, and tosylates via Suzuki-Miyaura cross-coupling reactions with sodium phthalimidomethyltrifluoroborate followed by deamidation with ethylenediamine is reported.