4(5)-Ary1-1H-imidazoles can be efficiently and selectively prepared by PdCl2(dppf)-catalyzed Suzuki-Miyaura reaction of commercially available 4(5)-bromo-1H-imidazole with arylboronic acids under phase-transfer conditions. On the other hand, N-unprotected 4(5)-aryl-1H-imidazoles can undergo highly selective Pd(OAc)(2)-catalyzed and CuI-mediated direct C-2-arylation with a variety of aryl bromides and iodides under base-free and ligandless conditions to produce 2,4(5)-diaryl-1H-imidazoles in modest to good yields. No N-arylation byproducts are observed under the experimental conditions used to Prepare 2,4(5)-diaryl-1H-imidazoles.
Efficient and practical synthesis of 4(5)-Aryl-1H-imidazoles and 2,4(5)-Diaryl-1H-imidazoles via highly selective palladium-catalyzed arylation reactions / F. Bellina, S. Cauteruccio, R. Rossi. - In: JOURNAL OF ORGANIC CHEMISTRY. - ISSN 0022-3263. - 72:22(2007), pp. 8543-8546. [10.1021/jo701496p]
Efficient and practical synthesis of 4(5)-Aryl-1H-imidazoles and 2,4(5)-Diaryl-1H-imidazoles via highly selective palladium-catalyzed arylation reactions
S. Cauteruccio;
2007
Abstract
4(5)-Ary1-1H-imidazoles can be efficiently and selectively prepared by PdCl2(dppf)-catalyzed Suzuki-Miyaura reaction of commercially available 4(5)-bromo-1H-imidazole with arylboronic acids under phase-transfer conditions. On the other hand, N-unprotected 4(5)-aryl-1H-imidazoles can undergo highly selective Pd(OAc)(2)-catalyzed and CuI-mediated direct C-2-arylation with a variety of aryl bromides and iodides under base-free and ligandless conditions to produce 2,4(5)-diaryl-1H-imidazoles in modest to good yields. No N-arylation byproducts are observed under the experimental conditions used to Prepare 2,4(5)-diaryl-1H-imidazoles.Pubblicazioni consigliate
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