Catalyst- and Solvent-Free Room Temperature Synthesis of α-Aminophosphonates: Green Accomplishment of the Kabachnik-Fields Reaction

A catalyst- and solvent-free room temperature method has been elaborated for the three-component (carbonyl compounds, primary or secondary amines and phosphites) Kabachnik-Fields synthesis of a-aminophosphonates. First, we have studied some parameters that potentially influence the course of the reaction using benzaldehyde, aniline and diethyl phosphite. In order to extend the reaction under the new reaction conditions, we then carried out 3 series of experiments always varying one of the three reagents. In general, with a few exceptions, good yields were obtained, although in some cases long reaction times were required.