676 J. Org. Chem. 2011, 76, 676–679 Published on Web 12/22/2010 DOI: 10.1021/jo102020a r 2010 American Chemical Society pubs.acs.org/joc Organocatalytic Stereoselective Epoxidation of Trisubstituted Acrylonitriles Claudia De Fusco, Consiglia Tedesco, and Alessandra Lattanzi* Dipartimento di Chimica, Universit  a di Salerno, Via Ponte don Melillo, 84084, Fisciano, Italy lattanzi@unisa.it Received October 11, 2010 The first diastereospecific and enantioselective epoxida- tion of trans-2-aroyl-3-arylacrylonitriles by means of the commercially available diaryl L-prolinol/tert-butyl hy- droperoxide system has been developed. These diversely functionalized epoxides were obtained in excellent yield (up to 99%), complete diastereoselectivity for the trans- isomer, and good enantioselectivity (up to 84% ee). Highly enantioenriched epoxides can be easily obtained after a single crystallization (ee > 90%). The asymmetric epoxidation of alkenes is a fundamental process given the pivotal role of chiral epoxides as targets of biological and pharmaceutical interest and most of all as synthetic intermediates amenable to a variety of manipula- tions of the epoxide ring. 1 Several electrophilic and nucleo- philic chiral metal-based and organocatalytic systems have been developed to date for the epoxidation of an array of alkenes. 2 In the area of nucleophilic epoxidation of electron- poor alkenes, numerous catalytic systems are available to effect this transformation, although most of them have limited substrate scope, essentially focused on R,β-unsaturated ketones as substrates. 3 Indeed, only a few protocols are suitable for the asymmetric epoxidation of R,β-unsaturated aldehydes, 4 cyclic enones, 5 R,β-unsaturated esters, 6 amides, and derivatives thereof. 7 The lantanoids/BINOLs/tert-butyl 8 hydroperoxide (TBHP) and polyleucine/H 2 O 2 /NaOH 9 sys- tems are likely among the most versatile protocols showing wider applicability. Surprisingly, studies have been almost exclusively restricted on the epoxidation of trans-disubsti- tuted electron-poor alkenes. Hence, expanding the substrate scope of the asymmetric nucleophilic epoxidation also to trisubstituted electron-poor alkenes would be highly desir- able, even in consideration of the access to versatile inter- mediates bearing quaternary stereocenters. To the best of our knowledge, Deng and coauthors 10 recently reported the first example of highly diastereo- and enantioselective epox- idation of trans-R-carbonyl-β-substitued acrylates mediated by TADDOL-derived hydroperoxide 11 (TADOOH) under basic conditions (Scheme 1). The corresponding epoxides proved to be key compounds employed for the first asymmetric total synthesis of (-)-plicatic acid, an agent causing inflammatory and allergic reactions. 12 Over the recent years, we developed a simple and convenient (1) For reviews, see: (a) Katsuki, T. Comprehensive Asymmetric Catal- ysis; Jacobsen, E. 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