Short communication Cellulose sulfuric acid as a bio-supported and recyclable solid acid catalyst for the one-pot three-component synthesis of a-amino nitriles Ahmad Shaabani * , Ali Maleki Department of Chemistry, Shahid Beheshti University, P.O. Box 19396-4716, Tehran, Iran Received 27 May 2007; received in revised form 16 July 2007; accepted 18 July 2007 Available online 22 July 2007 Abstract a-Amino nitriles are synthesized by a one-pot three-component condensation reaction of amines, aldehydes and trimethylsilylcyanide in the presence of a catalytic amount of cellulose sulfuric acid as a bio-supported catalyst, in excellent yields with short reaction times at ambient temperature. The reaction work-up is simple and the catalyst can be easily separated from the product and reused in subsequent reactions. # 2007 Elsevier B.V. All rights reserved. Keywords: Cellulose sulfuric acid; Bio-supported catalyst; a-Amino nitriles; Trimethylsilylcyanide; Multi-component reaction 1. Introduction a-Amino nitriles are an important and very useful class of intermediates for the synthesis of versatile a-amino acids, various nitrogen-containing heterocyclic compounds and other biologically useful molecules such as saframycin A [1–4]. Among various methods reported in the literature for the preparation of a-amino nitriles, the most important route for the synthesis of them is the Strecker reaction [5]. The classical Strecker reaction is generally carried out with alkaline cyanides in aqueous solution. The experimental procedure is tedious and, thus, several modified methods have been reported using a variety of catalysts such as LiClO 4 [6], Sc(OTf) 3 [7], vanadyl triflate [8], Ni(Cl) 2 [9], zinc halides [10,11], Ru(Cl) 3 [12], ytterbium triflate [13], Bi(Cl) 3 [14],H 14 [NaP 5 W 30 O 110 ] [15], Montmorillonite KSF [16], Cu(OTf) 2 [17], In(Cl) 3 [18], [bmim]BF 4 [19],I 2 [20] and NH 2 SO 3 H [21] under various conditions. However, most of these methods require expensive reagents, long reaction times, harsh reaction conditions and tedious work-up procedure and give unsatisfactory yields. Considering these facts, there is still a need to introduce new, efficient and inexpensive catalysts for this reaction. Biopolymers, especially cellulose and its derivatives [22], have some unique properties, which make them attractive alternatives for conventional organic or inorganic supports for catalytic applications. Cellulose is the most abundant natural material in the world and it has been widely studied during the past decades because it is a biodegradable material and a renewable resource. Recently, science and technology are shifting emphasis on environmentally friendly and sustainable resources and processes. In this regard, biopolymers are attractive candidates to explore for supported catalysis [23,24]. Several interesting biopolymers have been utilized as a support for catalytic applications, such as alginate [25], gelatin [26,27], starch [28] and chistosan [29] derivatives. In connection with our previous work using solid acid catalysts, and our interest in multi-component reactions [30– 34], we now report herein the facile synthesis of a-amino nitriles 4a–j, by a one-pot three-component condensation of an aldehyde 1, an amine 2, and trimethylsilylcyanide (TMSCN) 3, in the presence of a catalytic amounts of cellulose sulfuric acid [35,36] at ambient temperature in high yields with rather short reaction times (45–80 min) (Scheme 1). 2. Experimental 2.1. Instruments and characterization Melting points were measured on an Electrothermal 9100 apparatus and are uncorrected. The elemental analyses were performed with an Elementar Analysensysteme GmbH www.elsevier.com/locate/apcata Applied Catalysis A: General 331 (2007) 149–151 * Corresponding author. Tel.: +98 21 29902800. E-mail address: a-shaabani@cc.sbu.ac.ir (A. Shaabani). 0926-860X/$ – see front matter # 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.apcata.2007.07.021