Short Communication Magnetically recoverable Fe 3 O 4 @SBA-15: An improved catalyst for three component coupling reaction of aldehyde, amine and alkyne Diganta Bhuyan a , Mrinal Saikia a,b , Lakshi Saikia a,b, ⁎ a Materials Science Division, CSIR-North East Institute of Science and Technology, Jorhat 785006, Assam, India b Academy of Scientific and Innovative Research, New Delhi, India abstract article info Article history: Received 22 July 2014 Received in revised form 4 September 2014 Accepted 6 September 2014 Available online 18 September 2014 Keywords: Fe 3 O 4 @SBA-15 nanocomposite material Magnetically recoverable catalyst C–H activation A 3 coupling We have synthesized Fe 3 O 4 nanoparticles on mesoporous SBA-15 by an “in situ” approach. The synthesized nanocomposite material was well characterized using wide and low angle XRD, N 2 adsorption–desorption iso- therm, TEM, FTIR, XPS, and VSM analysis. The Fe 3 O 4 @SBA-15 nanocomposite material was used as a magnetically recoverable catalyst (MRC) for three component coupling reaction of aldehyde, amine and alkyne. The reported catalyst was recycled up to five times without significant loss in its catalytic activity. © 2014 Elsevier B.V. All rights reserved. 1. Introduction In the past few years, synthesis of nanocatalysts using environmen- tally benign methodology, having high catalytic activity, high chemical stability and easy separation process is highly desirable to address industrial and environmental concerns [1,2]. The strategy of magnetic separation of the catalysts attracted much attention over filtration or cen- trifugation as it prevents the loss of catalyst [3,4]. In recent years, Fe 3 O 4 is extensively studied as a magnetically recoverable catalyst (MRC) for var- ious organic transformations, e.g. synthesis of propargylamines [5,6] and α-aminonitriles [7], Sonagashira–Hagihara reaction [8], synthesis of 1,4-dihydroquinoline derivatives [9] etc. Although reports are avail- able of Fe 3 O 4 nanoparticle catalyzed organic reactions, it has certain drawbacks. As Fe 3 O 4 nanoparticles have a great tendency to deform and aggregate in organic solvents during the course of the reaction, its surface area is very less. Moreover, unmodified Fe 3 O 4 nanoparticles generally required higher amount of catalyst and takes longer reaction time [5–9]. In order to overcome these drawbacks, surface modification of Fe 3 O 4 nanoparticles by polymers or surfactants is demonstrated suc- cessfully, but organic surfactants have a tendency to decompose at high temperature [10,11]. Therefore, development of a suitable catalyst for these types of reactions is a challenging task. Propargylamines are versatile intermediates in various nitrogen containing organic compounds and key intermediates in various bioactive pharmaceutical drugs and natural products [12,13]. The tradi- tional synthesis of propargylamine derivatives are performed by nucle- ophilic attack of lithium acetylides or Grignard reagents on imines or their derivatives [14,15]. However, these reagents are highly moisture sensitive and so they require strictly controlled reaction conditions. In recent years, various homogeneous and heterogeneous catalysts were developed for efficient synthesis of propargylamines by C–H activation [5,6,16–23]. SBA-15 material was previously reported as an inert support of nanocatalysts for A 3 coupling reaction [23] and other organic reac- tions [24,25]. Herein, Fe 3 O 4 nanoparticles are synthesized on SBA-15 support by an “in situ” approach and the catalytic activity of the Fe 3 O 4 @SBA-15 nanocomposite material was studied for A 3 coupling reaction of aldehyde, amine and alkyne. 2. Experimental SBA-15 was synthesized as per the reported procedure [26]. Synthe- sis of Fe 3 O 4 @SBA-15, procedure for A 3 coupling reaction is provided as reference [35]. 3. Result and discussion The low angle XRD pattern of SBA-15 [Fig. S1 (a), ESI] corresponds to a 2D hexagonal symmetry. The well resolved (100), (110) and (200) reflections consistent with long-range mesopores ordering, appeared at 2θ values of 0.967, 1.641 and 1.865° respectively [26–31]. SBA-15 ex- hibited type IV N 2 adsorption–desorption isotherm [Fig. S1 (b), ESI] with H1 hysteresis loop and BJH pore size distribution curve [Fig. S1 Catalysis Communications 58 (2015) 158–163 ⁎ Corresponding author at: Materials Science Division, CSIR-North East Institute of Science and Technology, Jorhat 785006, Assam, India. Tel.: +91 376 2370 081; fax: +91 376 2370 011. E-mail address: lakshi_saikia@yahoo.com (L. Saikia). http://dx.doi.org/10.1016/j.catcom.2014.09.011 1566-7367/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Catalysis Communications journal homepage: www.elsevier.com/locate/catcom