1. Iron Catalysed Oxidation Reactions. Moftah Darwish and Martin Wills * * Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK. Conclusion: Bidentate ligands were tested in an asymmetric epoxidation, which requires 2:1 Ligand : FeCl 3.6H 2 O and one equivalent of pyridine-2,6-dicarboxylic acid.The pyridine and carboxylic group are reqired for high ee. Given the possible involvement of two equivalents of ligand in the reaction, a test for second order effects were completed by using a series of ligands with varying ee. In addition, a series of tetradentate ligands were synthesized and evaluated in the reaction. References: 1. Gelalcha, F. G.; Bitterlich, B.; Anilkumar, G.; Tse M. K.; Beller, M. Angew. Chem. Int. Ed. 2007, 46, 7293-7296. 2. a) Jorgensen, K. A. in Transition Metals for Organic Synthesis, vol. 2 (Ed. Beller, M.; Bolm, C.), Wiley-VCH, 1998, p. 157; b) Sundermeier, U.; Dobler, C. in Modern Oxidation Methods (Ed. Backvall, J. E.), Wiley-VCH, Weinheim, 2004, p. 1. 3. a) Tokunaga, M.; Larraw, J.; Kakiuchi, F.; Jacobsen, E. N. Science, 1997, 277, 936-938; b) Gayet, A.; Bertilsson, S.; Andersson, P. G. Org. Lett. 2002, 4, 3777-3779. 4. a) Katsuki, K. in Comprehensive Asymmetric Catalysis, Vol. 2 (Eds.: Jacobsen, E. N.; Pfaltz, A.; Yamamoto, H.), Springer, Berlin, 1999, pp. 621-648; b) Johnson, R. A.; Sharpless, K. B. in catalytic asymmetric synthesis (Ed.: Ojima, I.), Wiley-VCH, New York, 1993, pp. 103-158. Acknowledgement: I would like to thank my supervisor Prof. Martin wills and the Libyan Government for funding of this research project. EntryH 2 pydic %Solvent Conversion (%) Ee (%) Remarks 152-Methyl-2-butanol10041 (S,S) 252-Methyl-2-butanol62N/A6 % ligand 302-Methyl-2-butanol0N/A 452-Methyl-2-butanol10050 (S,S)* 55Dichloromethane0N/A 662-Propanol7834 (S,S) 75Ethanol20N/A 851-Butanol27N/A 952-Butanol67N/A 105tert-Butanol9244 (S,S) 116Acetonitrile9139 (S,S)14% ligand Table 1: Epoxidation of trans-stilbene under different conditions Results: Epoxidation of trans-stilbene under different conditions and a comparison of the efficiency of additives used in the epoxidation are summarized in Table 1 and Table 2. The combination of RR and SS configuration ligands indicated no second order effect (Graph 1). Several additives and different conditions were examined in order to establish which groups were essential for promotion of the reaction. Different bidentate and tetradentate ligands, were next investigated (Figure 2). The results of these studies, and the synthesis and applications of new ligands, is described and comparisons drawn with related asymmetric epoxidation processes. 2-4 Introduction: Iron-catalyzed asymmetric epoxidation of aromatic alkenes using iron complexes of TsDPEN derivatives, first disclosed by Beller, 1 has been studied. Epoxidation of aromatic alkenes with hydrogen peroxide is possible using catalyst consisting of ferric chloride hexahydrate (FeCl 3.6H 2 O), pyridine-2,6-dicarboxylic acid (H 2 pydic), and an organic base (Figure 1). EntryAdditive Conversion (%) Ee (%) 1Pyridine (5 %)12N/A 2Benzoic acid (5 %) 6N/A 3Pyridine-3-carboxaldehyde (5 %)13N/A 42-Piconilic acid (5 %)44N/A 5Nicotinic acid (5 %) 7N/A 6Isonicotinic acid (5 %) 6N/A 7L-proline (5 %) 0N/A 82-Piconilic acid (8 %)71N/A 92-Piconilic acid (12 %)882 (S,S) 102,6-Pyridine dicarbonyl dichloride (5 %)15N/A 11Dimethyl-2,6-pyridinedicarboxylate (5 %)10N/A Table 2: Comparison of the efficiency of additives used in the (Figure 1) * H 2 O 2 added in one portion