Eco-Friendly Accomplishment of the Extended Kabachnik-Fields Reaction; a Solvent- and Catalyst-Free Microwave-Assisted Synthesis of α- Aminophosphonates and α-Aminophosphine Oxides

The Kabachnik-Fields reaction may be carried out under a variety of conditions. More recently, the application of “exotic” catalysts, in most cases in traditional solvents and a few instances in ionic liquids, came into fashion. Using a pool of simple model compounds, still extending the scope of the reaction under discussion, it is shown that the simplest, most straightforward and most environmentally friendly accomplishment of the condensation of the oxo-component, the amine and the >P(O)H species to afford α-aminophosphonates or phosphine oxides involves microwave irradiation of the neat reaction mixture without the use of any catalyst. In some cases, the reaction is more clear-cut if the title compounds are prepared by a two-step one-pot procedure.