ORIGINAL PAPER A mild and clean Baeyer–Villiger oxidation of ketones using sodium peroxydisulfate as oxidant catalyzed by silica-supported aluminum chloride Nosrat Ollah Mahmoodi • Seyedeh Zahra Dalil Heirati • Kamel Ekhlasi-Kazaj Received: 18 February 2011 / Accepted: 10 October 2011 / Published online: 5 January 2012 Ó Iranian Chemical Society 2012 Abstract Sodium peroxydisulfate was used as the oxi- dant for Baeyer–Villiger oxidation of a variety of cyclic and acyclic ketones at room temperature in the presence of Silica-supported aluminum chloride (silica-AlCl 3 ) as cata- lyst. The catalyst was prepared by a simple procedure, which exhibited high catalytic activity for the Baeyer– Villiger oxidation of ketones using environmental friendly sodium peroxydisulfate as oxidizing agent. Keywords Baeyer–Villiger oxidation Á Silica-supported aluminum chloride Á Sodium peroxydisulfate Á Silica-AlCl 3 Introduction The Baeyer–Villiger oxidation is one of the major reactions in organic chemistry, particularly, in conversion of cyclic and acyclic ketones into lactones or esters by regioselective oxygen insertion into C–C bond [1]. Baeyer–Villiger oxi- dations traditionally have conducted using organic peracids such as trifluoroperacetic acid, perbenzoic acid and m-chloroperbenzoic acid. Excess utilization of these oxidants potentially produces large amounts of harmful wastes that lead to serious environmental problems [2–5]. In addition, the preparation of these reagents requires hazardous con- centration levels of hydrogen peroxide (H 2 O 2 ). Recently, there have been many researches trying to find chemically green reagents, oxidants and catalysts, which can overcome to abovementioned disadvantages [6, 7]. In this regard, a number of different catalytic systems have been developed to accomplish Baeyer–Villiger oxi- dation. The catalysts based on polymer-anchored metal complexes [8–10], solid acids [11, 12], zeolites [13], tita- nium silicalite [14], Sn-MCM-41 [15], sulphonated resins [16], Sn-synthesized hydrotalcites [17], Sn-b zeolite [18], hydrotalcite-supported Sb catalyst [19], Pt [20], Zr [21], Re [22], Se [23], As [24] and Mo [25] are examples of some of the heterogeneous and homogeneous catalysts used to perform the Baeyer–Villiger oxidation. These catalysts activate H 2 O 2 as a clean oxidant by increasing its nucleo- philicity and facilitate attack by the oxidizing species on the carbonyl carbon atom [26]. Most of these processes, however, suffer from some disadvantages like low activity or selectivity and expensive catalyst or the need for high concentration of H 2 O 2 . In order to overcome the above problems, the new effective heterogeneous catalysts based on cellulose-sup- ported dendritic Sn complex [27] montmorillonite (MMT) supported tin (II) chloride [28], Sn-palygorskite [29] and aminomethyl polystyrene resin-supported tin complex [30] were reported for the chemoselective Baeyer–Villiger oxidation of a variety of cyclic and acyclic that can selectively activate the ketone instead of the H 2 O 2 . This way readily leads to increase of the positive charge on the carbon atom of the carbonyl group and facilitates the nucleophilic attack on this group by H 2 O 2 . Therefore, high yields and excellent selectivities can obtain in low con- centration of H 2 O 2 using these catalytic systems. As another potential catalyst for this reaction, Lei et al. [31] have recently used a silica-supported aluminum chloride heterogeneous catalyst containing 2.65% Al with H 2 O 2 as oxidant, for the chemoselective Baeyer–Villiger oxidation of a variety of cyclic and acyclic ketones at 70 °C. The utilization of hydrogen peroxide as oxidizing N. O. Mahmoodi Á S. Z. D. Heirati (&) Á K. Ekhlasi-Kazaj Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 41335-1914, Rasht, Iran e-mail: raha.heirati@gmail.com 123 J IRAN CHEM SOC (2012) 9:521–528 DOI 10.1007/s13738-011-0064-1