A new polyamine was prepared by the ring opening polymerization of epichlorohydrin and properly characterized. The catalytic property of the prepared polymer was assessed by synthesizing 2‐aryl‐substituted benzimidazole and benzoxazole derivatives by the conjugation of o‐phenylenediamine/o‐aminophenol with various aromatic aldehydes in the presence of atmospheric oxygen. Significant attributes of the present synthesis include short reaction time, good to excellent yield, high purity, easy reusability, and room temperature reaction. The reaction was carried out in the absence of any metal catalyst and other cooxidants.