One-pot synthesis of novel alpha-amino phosphonates using tetramethylguanidine as a catalyst

alpha-Aminophosphonates (4a-I) were synthesized in high yields by the Kabachnik-Fields reaction. One-pot simultaneous reaction of indole-3-carboxaldehyde, a dialkyl- or diphenyl phosphite, and different heterocyclic-, cyclic-, or other primary amines in the presence of tetramethylguanidine (10 mole %) as catalyst in toluene at reflux temperature afforded 4a-I. They exhibited moderate to high antimicrobial activity.