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.
§ 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
We have successfully developed the I2-catalysed synthesis of substituted imidazole derivatives from amidines and ketones in good to excellent yields and 100% regioselectivity.
A one-pot, four-component synthesis of 1,2,4-trisubstituted 1H-imidazoles is described. Heating a mixture of a 2-bromoacetophenone, an aldehyde, a primary amine, and ammonium acetate under solvent-free conditions affords functionalized imidazoles in good to excellent yields.