A few phosphinicacids, such as phenylphosphinic acids, 1-hydroxy-3-phospholene 1-oxides and 1-hydroxyphospholane oxides are esterified with simple alcohols in the presence of propylphosphonic anhydride (T3P®). If 1.1 equiv of the T3P® reagent is used, the esterifications are fast and efficient at 25° C. In the case of more reactive models it was enough to apply 0.66 equiv of T3P® at 85° C under microwave
Depending on the molar ratio of the reactants and on the order of mixing, the reactions of a series of primary amines with 1-chloro-2,5-dihydro-1H-phosphole 1-oxides prepared in situ from the corresponding hydroxy-dihydrophosphole oxides afforded 1-amino-2,5-dihydro-1H-phosphole 1-oxides, or their N-phosphinoyl derivatives, bis(2,5-dihydro-1H-phosphol-1-yl)amine P,P'-dioxides. The latter family of P-heterocycles could also be synthesized by the reaction of 1-amino-2,5-dihydro-1H-phosphole oxides with chloro-dihydrophosphole oxides.