<p>α,β-Unsaturated imines carrying cinnamoyl moiety are used for the synthesis of novel azaphosphole substitutes. 1-(4-Chlorophenyl)-2-(diethylamino)-3-phenyl-1,5-dihydro-1,2-azaphosphole-2-oxide and phosphonate compounds are produced by 1,4-nucleophilic attack of aminophosphine on cinnamylidene-4-chloroaniline. Furthermore, <i>N</i>-(3-phenylallylidene)thiazol-2-amine reacted with trisaminophosphine in dry boiling toluene to produce thiazol-1,2-azaphosphole-2-oxide adduct. The reactions of imine derivatives of 4-acetocinnamone with aminophosphine produced new cyclic azaphosphole 1,2-azaphosphole-2-oxide derivatives. Structural elucidations for the new products are based upon IR, MS, and ¹H, ¹³C NMR spectroscopic data. Moreover, the structure assigned for compound 2-(diethylamino)-3-phenyl-1,5-dihydro-1,2-azaphosphole-2-oxide is unambiguously confirmed by X-ray crystallographic measurements.</p> Graphical Abstract <p></p>