β‐chloro aldimines with terminal alkynes leading to a rapid and efficient formation of 2‐alkynylazetidines in good to excellent yield has been described. The catalytic hydrogenation of the 2‐alkynylazetidines resulted in acyclic secondary amines by reductive cleavage of the 2‐alkynylazetidine. Further, these non‐activated 2‐alkynylazetidines were ring expanded in a reaction with dimethyl acetylenedicarboxylate