Effective and Variable Functionalization of Pyrazolo[1,5-a]pyridines Involving Palladium-Catalyzed Coupling Reactions

Abstract

Various 7-substituted pyrazolo[1,5-a]pyridines were synthesized by palladium-mediated cross-coupling reactions. Starting from the corresponding 7-iodo derivatives, incorporation of phenyl, vinyl, ethynyl, cyano, and amino was accomplished. Pyrazolo[1,5-a]pyridine-7-ylzinc iodide could be reacted under Negishi conditions to afford the coupling product 16.