Efficient and Practical Synthesis of 4(5)-Aryl-1<i>H</i>-imidazoles and 2,4(5)-Diaryl-1<i>H</i>-imidazoles via Highly Selective Palladium-Catalyzed Arylation Reactions
作者:Fabio Bellina、Silvia Cauteruccio、Renzo Rossi
DOI:10.1021/jo701496p
日期:2007.10.1
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
通过PdCl 2(dppf)催化的Suzuki-Miyaura反应可在相转移条件下对市售4(5)-bromo-1 H-咪唑与芳基硼酸进行反应,可有效地选择性制备4(5)-Aryl-1 H-咪唑条件。另一方面,N-未保护的4(5)-芳基-1 H-咪唑可在碱下与多种芳基溴化物和碘化物进行高选择性Pd(OAc)2催化和CuI介导的直接C-2-芳基化无和无配体的条件下,以适度到良好的产率生产2,4(5)-二芳基-1 H-咪唑。在用于制备2,4(5)-二芳基-1 H-咪唑的实验条件下未观察到N-芳基化副产物。