A reliable method for preparing P(III)‐arylphosphinecarboxamide derivatives from N‐arylphosphinecarboxamides and aryne precursors has been developed. This reaction was carried out without transition‐metal catalysts, and a series of unsymmetrically structured phosphinecarboxamide derivatives were obtained under mild conditions. In addition, the reaction is carried out under air atomosphere, and the corresponding P(III)‐aryl phosphinecarboxamide compounds are also stable in air.