Kabachnik-Fields Reaction by Mechanochemistry: New Horizons from Old Methods

alpha-Aminophosphonates are an important class of biologically active compounds, attracting considerable attention in medicinal chemistry, by inhibiting enzymes involved in amino acid metabolism. Herein, the Kabachnik-Fields domino reaction was investigated by mechanochemistry for the first-time preparation of alpha-aminophosphonate derivatives in high yields and with full selectivity, outperforming comparable solution procedures. The reaction occurs without the addition of any external catalyst, possibly via a metal-mediated process occurring on the surface of the jar (zirconium oxide was used as the milling media). The mechanism of the mechanochemical reaction was also investigated by in situ Raman spectroscopy, and the kinetic behavior was disclosed. The solid-state structures of two representative compounds have been determined by single-crystal X-ray diffraction.