Water mediated deprotective intramolecular hydroamination of N-propargylaminopyridines: synthesis of imidazo[1,2-a]pyridines
摘要:
Metal-free synthesis of substituted imidazole [1,2-alpha]dpyridines from deprotective N-(prop-2-yn-1-yl)pyridin-2-amines in water is elucidated. Electron releasing substituents on pyridine ring provided pure products in quantitative yields without separation by column chromatography. (C) 2013 Elsevier Ltd. All rights reserved.
Aqueous syntheses of methylimidazo[1,2-a]pyridines without any deliberate addition of catalyst are reported. Imidazo[1,2-a]pyrazine and imidazo[2,1-a]isoquinoline were also obtained in good yields under similar conditions. With acetonitrile as solvent, Ag-catalyzed intra-molecular aminooxygenation produced imidazo[1,2-a]pyridine-3-carbaldehydes in moderate to good yields.