Vol.:(0123456789) 1 3 Catal Lett DOI 10.1007/s10562-017-2166-6 Nano Copper(0)-Stabilized on Alumina: Efficient and Recyclable Heterogeneous Catalyst for Chemoselective Synthesis of 1,2-Disubstituted Benzimidazoles and Quinoxalines in Aqueous Medium Jaya Pogula 1  · Soumi Laha 1  · Pravin R. Likhar 1   Received: 25 May 2017 / Accepted: 7 August 2017 © Springer Science+Business Media, LLC 2017 ranges of substituted o-phenylenediamines and aldehydes or α-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. Graphical Abstract A simple and efficient process for the synthesis of benzimidazoles and quinoxaline in presence of Cu(0)/Al 2 O 3 catalyst at room temperature is described. Keywords Benzimidazole · Quinoxaline · Heterogeneous catalysis · Copper nanoparticles on alumina · Recyclability · Aqueous medium 1 Introduction Benzimidazole and quinoxaline are important N-heterocyclic units in pharmaceutical industry due to their broad biologi- cal functions such as antiviral, antiulcer, antihypertensive and anticancer activities [1–5]. Additionally, benzimidazole Abstract 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 selec- tive 1,2-disubstituted benzimidazoles and quinoxaline. Wide Electronic supplementary material The online version of this article (doi:10.1007/s10562-017-2166-6) contains supplementary material, which is available to authorized users. * Pravin R. Likhar plikhar@iict.res.in 1 Organometallic Gp., I& PC Division, CSIR-IICT, Hyderabad 500007, India