Highly Efficient Copper-Catalyzed N-Arylation of Nitrogen-Containing Heterocycles with Aryl and Heteroaryl Halides

Abstract

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.

Copper‐Catalyzed One‐Pot Synthesis of Imidazo/Benzoimidazoquinazolinones by Sequential Ullmann‐Type Coupling and Intramolecular CH Amidation

“…A 47 % yield was achieved in the absence of any ligand (Table 1, entry 12). The effect of the base was also investigated (Table 1, entry 1 versus entries [13][14][15][16] and Cs 2 CO 3 showed the highest efficiency. We screened various solvents and dry DMSO was superior (Table 1, entry 1 versus entries [17][18][19].…”

“…In recent decades, there has been remarkable progress in copper-catalyzed cross-couplings with inexpensive, low-toxicity copper catalysts, and wide applications with good functional group tolerance have been investigated. [13,14] Recently, several examples for efficient copper-catalyzed sp 2 -CÀH amination/amidation have been reported, [15] and some heterocycles have been constructed through copper-promoted arene sp 2 -CÀH activation [16] by using air/ O 2 as the ideal oxidant. [17] Herein, we report a convenient and efficient copper-catalyzed one-pot synthesis of imidazo/ benzoimidazoquinazolinones by sequential Ullmann-type coupling and aerobic oxidative intramolecular C À H amidation.…”

Kinetic Template‐Guided Tethering of Fragments

“…[283] D-prolinol (0.50 mL, 5.12 mmol, 1.0 equiv.) was added to formic acid (1 mL) at 0 °C followed by 37 % aqueous formaldehyde (0.75 mL).…”

Benzotriazol-1-ylmethanol: An excellent bidentate ligand for the copper/palladium-catalyzed C-N and C-C coupling reaction

“…3c Although, there are lot of development in palladium-catalyzed C-N bond forming reactions 6 but the copper catalyzed N-arylations of N-heterocycles with aryl halides promoted by ligands attracted much attention due to its economy and efficiency. 2,6 So far, many efficient ligands have been used with copper such as (S)-pyrrolidinylmethylimidazoles, 7 diazabutadiene, 8 2-aminopyrimidine-4, 6-diol, 9 1,10-phenanthroline derivatives, 10 diamines, 11 aminoarenethiol, 12 amino acid derivatives, 13 8-hydroxyquinoline, 14 pyrrolidine-2-phosphate, 15 oxime-phosphine oxides, 16 phosphoramidite, 17 N-hydroxymaleimide, 18a acylhydrazone 18b and L-histidine, 19 while various phosphine ligands have been explored in the case of palladium-catalyzed reactions. 2f The Pd-catalyzed C-C coupling reaction (Suzuki-Miyuara) also represents one of the most synthetically valuable methods for the synthesis of biaryl derivatives.…”