Synthesis of Functionalized Pyrazolo[1,5-a]pyridines: [3+2] Cycloaddition of N-Aminopyridines and α,β-Unsaturated Carbonyl Compounds/Alkenes at Room Temperature

The synthesis of functionalized pyrazolo[1,5-a]pyridines through oxidative [3+2] cycloaddition of N-aminopyridines with α,β-unsaturated carbonyl compounds or electron-withdrawing olefins is described. The reactions proceed in N-methylpyrrolidone as the solvent under metal-free conditions at room temperature.