Solvent-free sonochemical kabachnic-fields reaction to synthesize some new α-aminophosphonates catalyzed by nano-BF<sub>3</sub>•SiO<sub>2</sub>

<p>To obtain a rapid, efficient synthesis of some new α-aminophosphonates, ultrasonic irradiation has been applied to the reaction mixtures containing amine, aromatic or heteroaromatic aldehydes and triethyl phosphite. The Kabachnik-Fields reaction was performed by using nano-BF<sub>3</sub>•SiO<sub>2</sub> as a recyclable catalyst under solvent free conditions. Key advantages of this procedure consist in the eco-friendly and highly efficient reaction conditions, high yields, an easy work-up procedure, short reaction times and solvent free conditions. All title compounds were characterized by spectral and elemental analysis. They were further screened for their <i>in vitro</i> antioxidant activity by the DPPH, O<sup>2−</sup> and NO methods. The majority of the title compounds showed good antioxidant activity when compared with the standard antioxidants.</p>