Synthesis of 2-phosphonylated imidazo[1,2-a]pyridines under catalyst-free conditions

Abstract A series of novel 2-phosphonylated imidazo[1,2- a ]pyridines was accessed from C N coupling of chloroethynylphosphonates and commercially available N -unsubstituted 2-aminopyridines. The product yield depends on the nature and position of the substituent in the pyridine ring.