Quantum-chemical investigation of reactions of (dialkylamino)ethynylphosphonates with amines

Structural parameters and molecular energies of diethyl piperidylethynylphosphonate, dimethyl (diethylamino)ethynylphosphonate, dimethyl2-(t-butylamino)-2-(diethylamino)vinyl]phosphonate, N,N-diethyl-N′-t-butyl(dimethoxyphosphinoyl)acetamidine, dimethyl 2-(diethylamino)-2-(phenylamino)vinyl]phosphonate, N,N-diethyl-N′-phenyl(dimethoxyphosphinoyl)acetamidine, and the cations formed by protonation of the phosphinoyl group, nucleophilic carbon atom, or nitrogen were determined by means of B3LYP/6-311G(d₅,p)&;6-31G(d₅,p) quantum-chemical calculations. Acid-base properties of the related amines and their adducts with boron trifluoride in CCl₄ are estimated. The mechanism of the reactions of (dialkylamino)ethynylphosphonates with amines is discussed.