The present communication elicits the use of copper nanoparticles on aluminium oxide derived from Cu-Al hydrotalcite as a heterogeneous catalyst in the green and operationally simple approach for the synthesis of selective 1,2-disubstituted benzimidazoles and quinoxaline. Wide ranges of substituted o-phenylenediamines and aldehydes or alpha-bromo ketones were used to achieve the desired products using water as the reaction medium. The recoverability and reusability of the catalyst are the significant features in this eco-friendly green protocol. A simple and efficient process for the synthesis of benzimidazoles and quinoxaline in presence of Cu(0)/Al2O3 catalyst at room temperature is described.