rings: Treatment of N‐arylallylamine with an aryl or alkenylhalide under palladium catalysis (see scheme; dba=dibenzylideneacetone, SPhos=2‐dicyclohexylphosphanyl‐2′,6′‐dimethoxybiphenyl) resulted in intramolecular cyclization to form the arylmethyl‐substituted aziridine with concomitant CC bond formation. The experiments for the elucidation of the reaction mechanism are also described.