Synthesis of a succession of new α‐aminophosphonates 4a‐j was achieved by the one‐pot three‐component Kabachnik‐Fields reaction by reacting equimolar quantities of 4‐morpholinoaniline (1), a variety of aromatic aldehydes 2a‐j and diethyl phosphite (3) using silica‐supported zinc bromide (ZnBr2‐SiO2) as a catalyst in solvent‐free conditions under microwave (MW) irradiation. Products 4a‐j were characterized by IR, 1H, 13C, 31P, NMR and mass spectral data. For these new set of compounds, two‐dimensional structures are drawn, three‐dimensional coordinates are generated and studied for their anti‐cancer activity against breast cancer. To support theoretical findings, experimental studies are performed using breast cancer cell lines. The results of these studies suggested that analogue, 4f has the maximum activity against breast cancer cells (MDA‐MB‐231). Since α‐aminophosphonates are less toxic compared to drugs currently available in the market, this new classes of drugs have very good potential for the treatment of Breast cancer.