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.
|Titolo:||Efficient and practical synthesis of 4(5)-Aryl-1H-imidazoles and 2,4(5)-Diaryl-1H-imidazoles via highly selective palladium-catalyzed arylation reactions|
|Settore Scientifico Disciplinare:||Settore CHIM/06 - Chimica Organica|
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||10.1021/jo701496p|
|Appare nelle tipologie:||01 - Articolo su periodico|