Base-Mediated Syntheses of Di- and Trisubstituted Imidazoles from Amidine Hydrochlorides and Bromoacetylenes
作者:Xiao Yun Chen、Ulli Englert、Carsten Bolm
DOI:10.1002/chem.201502707
日期:2015.9.14
A new transition metal‐free method for the preparation of substituted imidazoles from easy‐to‐handle amidinehydrochlorides and bromoacetylenes has been developed. The reactions proceed in air and use inexpensive K2CO3 as base. Additions of 2,2′‐bipyridine and water have beneficial effects on the product yields. Various di‐ and trisubstituted imidazoles have been prepared in good yields (up to 88 %)
已开发出一种新的无过渡金属的方法,该方法由易于处理的am盐酸盐和溴乙炔制备取代的咪唑。反应在空气中进行,并使用廉价的K 2 CO 3作为碱。添加2,2'-联吡啶和水对产品收率有有利影响。各种二,三取代的咪唑均以高收率(高达88%)制备。
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 iodidesunderbase-free and