Chinese Journal of Catalysis 34 (2013) 2217–2222 催化学报 2013年第34卷第12期 | www.chxb.cn available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/chnjc Article Cu(ΙI) salen complex catalyzed synthesis of propargylamines by a three‐component coupling reaction Mahmood Tajbaksh a, *, Maryam Farhang a , Hamid Reza Mardani b , Rahman Hosseinzadeh a , Yaghoub Sarrafi a a Faculty of Chemistry, Mazandaran University, Babolsar, 47415, Iran b Department of Chemistry, Payame Noor University, Iran ARTICLE INFO ABSTRACT Article history: Received 10 June 2013 Accepted 20 August 2013 Published 20 December 2013 A one pot three‐component coupling reaction of phenylacetylene, aldehyde, and amine derivatives in the presence of Cu(II) Salen complex as an efficient heterogeneous catalyst under solvent‐free conditions is reported. The catalyst displayed high activity and afforded the corresponding propar‐ gylamines in good to excellent yields. This method provides a wide range of substrate applicability. The catalyst was reused several times without significant loss of its catalytic activity. © 2013, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved. Keywords: Propargylamine Salen Copper Coupling reaction Solvent‐free 1. Introduction Propargylamines are important synthetic intermediates for the synthesis of potential therapeutic drug molecules. Poly‐ functional amino derivatives are versatile building blocks and are value‐added intermediates in organic synthesis [1]. Tradi‐ tionally, propargylamines have been prepared by the amination of propargylic halides [2], propargylic phosphates [3], and propargylic triflates [4] or through the nucleophilic attack of lithium acetylides and Grignard reagents on imines or their derivatives [5]. However, these methods suffer from issues such as moisture sensitivity and the requirement for strictly controlled reaction conditions. Recently, a three‐component coupling among aldehyde, alkyne, and amine, commonly re‐ ferred to as A 3 coupling, has been reported to be a convenient and general approach for the preparation of propargylamines [6]. Generally, the A 3 coupling reaction is catalyzed by transi‐ tion metals by C–H activation. For example, Ag(Ι) salts [7], Au(Ι,ΙΙΙ) salts [8], Au(ΙΙΙ) salen complexes [9], Cu(Ι) salts [10], Ir complexes [11], Hg2Cl2 [12], Zn salts [13], InCl3 [14], InBr3 [15], and the Cu/Ru bimetallic system [16] under homogeneous conditions. Recently Ag(I) [17] and Cu(I) [18] in ionic liquids and supported Au(III) [19], Ag(I) [20], and Cu(I) [21] were successfully used to catalyze three‐component coupling reac‐ tions under heterogeneous conditions with catalyst recycling and reuse. However, some of these methods require expensive metal catalysts (Ag, Au, Ir, etc.) [7,8,11], hazardous catalysts [12], inert conditions [16], harmful solvents [13,15], and long reaction times [9,21] and catalyst recycling can be difficult [7–14]. On the other hand, salen complexes are stable solid compounds that have been used as catalysts for various organic transformations [22–24]. Herein, we report a high yield syn‐ thesis of propargylamines catalyzed by the Cu(ΙI) salen com‐ plex 1a under solvent‐free conditions at 80 °C (Scheme 1). * Corresponding author. Fax: +98‐1125242002; E‐mail: Tajbaksh@umz.ac.ir DOI: 10.1016/S1872‐2067(12)60683‐4 | http://www.sciencedirect.com/science/journal/18722067 | Chin. J. Catal., Vol. 34, No. 12, December 2013