One-Pot Protocol for the Synthesis of Imidazoles and Quinoxalines using<i>N</i>-Bromosuccinimide
作者:Sachin D. Pardeshi、Pratima A. Sathe、Kamlesh S. Vadagaonkar、Atul C. Chaskar
DOI:10.1002/adsc.201700900
日期:2017.12.11
N‐bromosuccinimide (NBS)‐mediated one‐pot, green, efficient and practical synthesis of substituted imidazoles and quinoxalines has been achieved by the reaction of styrenes with N‐arylbenzamidines and o‐phenylenediamines, respectively, in a water:1,4‐dioxane mixture. The reaction involves formation of an α‐bromo ketone as an intermediate in the presence of NBS and water, followed by condensation with
Facile Synthesis of 1,2,4-trisubstituted Imidazoles via Aerobic Copper Catalyzed Ligand-free [3+2] Cycloaddition
作者:Wei Li、Weixiang Tian、Ming Lei
DOI:10.2174/1570178611666140207221202
日期:2014.4
A simple and facile approach to highly functionalized imidazole derivatives in moderate to good yields has
been developed. This method involves copper catalyzed aerobic [3+2] cycloaddition of amidines with nitroolefins in
absence of ligand. Based on observation of the intermediates, possible reaction mechanism different from the same
reported approach was proposed.
A simple route for the synthesis of imidazole derivatives via copper-catalyzed [3 + 2] cycloaddition reaction is described. This strategy has achieved high regioselectivity and used oxygen as an oxidant without the addition of expensive catalysts to provide moderate to good yields.
§ Authors contributed equally to this work. Abstract A copper-catalyzed expedient, practical, and straightforward approach for the one-pot three-component modular synthesis of multisubstituted imidazoles has been described by using arylacetic acids, N-arylbenzamidines, and nitroalkanes. The reaction involves simultaneous activation of C–H and N–H bonds of arylacetic acids and N-arylbenzamidines, respectively
A novel and simple t‐BuOLi/I2‐mediated synthesis of 1,2,4‐trisubstituted imidazoles was developed without transition‐metal added. The transition‐metal‐free strategy tolerated a range of substrates and provided products in moderate to good yields with 100% regioselectivity.
在不添加过渡金属的情况下,开发了新颖,简单的t- BuOLi / I 2介导的1,2,4-三取代咪唑合成方法。不含过渡金属的策略可耐受多种底物,并提供中等至良好产率的产品,区域选择性为100%。