One-Pot Synthesis of α-Amino Phosphonates with ZnO Nanoparticles

Significance

Zinc oxide nanoparticles (ZnO NPs, ca. 22 nm) catalyzed the three-component coupling of aromatic amines 1, aldehydes 2, and dialkyl phosphites 3 at ambient temperature under solvent-free conditions to give the corresponding α-amino phosphonates 4 in 72-91% yield (19 examples). The catalyst was readily removed from the reaction mixture by centrifugation and reused five times with minor decrease of its catalytic activity (for the formation of 4a, 2^nd use: 89% yield, 5^th use: 84% yield).