One-step synthesis of cyanated pyrazolo[1,5-a]pyridines utilizing N-aminopyridines as a 1,3-dipole and a nitrogen source

Abstract

By utilizing the dual reactivity function of N-aminopyridinium ylides, we developed a direct [3 + 2]-cycloaddition of N-aminopyridinium ylides and ynals to build the pyrazolo[1, 5-a]pyridine core while introducing a cyano group. In the transformation, N-aminopyridinium ylide serves as a 1,3-dipole and a nitrogen source, which results in the production of cyanated pyrazolo[1,5-a]pyridines and pyrazolo[1,5-a]pyrazines with a wide scope.