1-(2′-Benzimidazolylmethyl)-pyridinium ylide in the one-pot synthesis of indolizine and benzimidazo[1,2-a]pyridine derivatives

Abstract Four indolizine derivatives were obtained via 1,3-dipolar cycloaddition reaction of 1-(2′-benzimidazolylmethyl)pyridinium ylide with various electron-deficient alkynes. The reaction of this pyridinium N-ylide with dimethyl maleate gave an unexpected methyl 1-oxo-benzimidazo[1,2-a]pyridine-3-carboxylate. The structures of all reported compounds have been examined by X-ray crystallography and NMR spectroscopy.