Abstract An efficient pathway for the selective preparation of monopropargyl-substituted phosphonocarboxylate (PC) has been developed via the addition of sodium acetylenide to ethylidenephosphonate. The reaction works perfectly on multi-gram scales. The synthesis of the corresponding methyl (propargyl)-, trifluoromethyl (propargyl)-, and dipropargyl- substituted derivatives was elaborated based on direct alkylation of either the ...