RESEARCH ARTICLE Microwave‐assisted facile synthesis of propargylamine library by robust nitro functionalized cross‐linked polystyrene resin supported Cu NPs Anuj S. Sharma | Harjinder Kaur | Nirav Barot Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad, India Correspondence Harjinder Kaur, Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad, India. Email: hk_ss_in@yahoo.com Funding information GUJCOST, Grant/Award Number: /MRP/ 2014‐15/403 Abstract In the present investigation, we study catalytic activity of copper nanoparticles stabilized onto a nitro functionalized polystyrene resin (Cu NPs@ Nitro‐Resin). The size of stabilized copper nanoparticles was found between 3 and 9 nm. This work reports a cost‐effective and sustainable protocol for the synthesis of propargylamines. Herein, we have developed microwave‐assisted synthesis of propargylamine from 3 components coupling of aldehyde, alkynes, and amines (A 3 coupling) in truly heterogeneous catalytic system. Reaction parameters, such as solvent, catalyst concentration reaction time, and recyclability, were investigated, and reaction conditions were optimized. The present method has advantages such as environmentally benign, ease to handle, short reaction time (≈25 min), excellent yields (98%), low E‐factor (0.15), and high atom economy (94%). KEYWORDS A 3 coupling, microwave heating, nanocatalysis, propargylamines, resin supported nanoparticles 1 | INTRODUCTION In the 21st century, there has been an increased awareness towards green chemistry approach to synthesize of important organic moieties. The need for developing sus- tainable reaction protocols with state‐of‐the‐art use of technology, alternate reaction media, energy saving, waste minimization, etc has become vital. One such tech- nique that has gained attention is synergistic use of microwave reactors and nanoparticles as catalyst. In the last few decades, microwave radiation in synthetic organic chemistry became popular and attracted consid- erable practical and theoretical attention along with the development of resource friendly and environmentally benign processes in terms of sustainable chemistry. [1,2] Although use of homogeneous and heterogeneous cata- lysts is common under microwave heating, there are some important parameters that need to be looked carefully. During the reaction process, there is not only usual agglomeration and Ostwald ripening of nanoparti- cles but also increased chances of sintering and hot spot development even at low temperature as metal nanoparti- cles are efficient absorbers of microwave. So careful choice of solvents, supports, reaction temperature, etc needs to be evaluated. [3–6] Transition metal catalyzed multicomponent reactions are a powerful synthetic strategy to generate multiple molecular scaffolds and to increase structural as well as skeletal, diversity from simple and readily available mole- cules. [7] Three components coupling of aldehyde, alkynes, and amines (A 3 coupling) is one of the best examples of such a process, and this transformation has received much more attention in recent year. Propargylamine scaffolds show remarkable biological activity and are used in drugs such as rasagiline, a potent cardiovascular drug. [8] Besides, they also act as enzyme inhibitors, [9] antitumor, [10] Received: 16 February 2017 Revised: 25 April 2017 Accepted: 30 June 2017 DOI: 10.1002/poc.3749 J Phys Org Chem. 2017;e3749. https://doi.org/10.1002/poc.3749 Copyright © 2017 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/poc 1 of 8