An Improved Synthesis of Imidazo[4,5-<i>b</i>]pyridines and Imidazo[4,5-<i>b</i>]pyrazines by Palladium Catalyzed Amidation using Xantphos in a 1,4-Dioxane:<i>tert</i>-Amyl Alcohol Solvent System
作者:Adam J. Rosenberg、Ijaz Ahmed、Robert J. Wilson、Theresa M. Williams、Lauren Kaminsky、Daniel A. Clark
DOI:10.1002/adsc.201400465
日期:2014.11.3
AbstractHerein an improved protocol for the synthesis of imidazo[4,5‐b]pyridines and imidazo[4,5‐b]pyrazines using a palladium‐catalyzed amidation that utilizes Xantphos as an ancillary phosphine ligand is reported. The use of a binary solvent system comprised of 1,4‐dioxane and tert‐amyl alcohol was crucial in eliminating unwanted by‐products.magnified image
Synthesis of Imidazo[4,5-<i>b</i>]pyridines and Imidazo[4,5-<i>b</i>]pyrazines by Palladium Catalyzed Amidation of 2-Chloro-3-amino-heterocycles
作者:Adam J. Rosenberg、Jinbo Zhao、Daniel A. Clark
DOI:10.1021/ol300359s
日期:2012.4.6
A facile synthesis of imidazo[4,5-b]pyridines and -pyrazines is described using a Pd-catalyzed amide coupling reaction. This reaction provides quick access to products with substitution at N1 and C2. A model system relevant to the natural product pentosidine has been demonstrated, as well as the total synthesis of the mutagen 1-Me-5-PhIP.
使用Pd催化的酰胺偶联反应描述了咪唑并[4,5- b ]吡啶和-吡嗪的简便合成方法。通过该反应,可以快速获得在N1和C2处被取代的产物。已经证明了与天然产物戊糖苷有关的模型系统,以及诱变剂1-Me-5-PhIP的全合成。