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A simple and highly efficient approach has been developed for a multicomponent one-pot reaction of aldehydes or ketones with amines and diethyl or triethyl phosphite to give the corresponding α-aminophosphonates. In the presence of quaternary ammonium salts, which are environmental friendly, inexpensive, and recyclable, α-aminophosphonates were obtained in excellent yields at room temperature within short times.

The scalable, operationally simple one-pot multicomponent procedure provides the products with high to excellent yields.

Polystyrene-supported DABCO was employed for the first time as a recyclable heterogeneous basic catalyst for one-pot synthesis of β-phosphonomalonates via tandem Knoevenagel–phospha-Michael reaction at room temperature. The reaction conditions are mild and the method is operationally simple. The catalyst could be easily separated from the reaction mixture by filtration and recycled six times without activity loss.

A novel and simple approach to the multicomponent one-pot reaction of aldehydes, diethyl phosphite, and azides to form α-aminophosphonates under solvent-free conditions at room temperature has been developed. In the presence of iodine and iron, aryl azides were, for the first time, used as substrates for the synthesis of α-aminophosphonates. The reactions were completed within 5 minutes to 12 hours and afforded the corresponding products in good yields.

A novel and efficient route for the regioselective synthesis of 5-aryl-2-[(4-aryl-2-oxo-1,3,2-dioxaphosphinan-2-yl)imino]-2,3-dihydro-1,3,4-oxadiazoles in high yield and purity by the de-sulfurization and cyclization of 1-benzoyl-4-[(4-aryl-2-oxo-1,3,2-dioxaphosphinan-2-yl)thiosemicarbazides under mild conditions is reported. The products are isolated as the TRANS-isomer only.