1999 oxirane derivatives

oxirane derivativesR 0030

28 - 136Exocyclic Iminium Salts as Catalysts for Alkene Epoxidation byOxone r©. — Among several evaluated iminium triflates derived frompyrrolidine and aromatic aldehydes, the ortho-trifluoromethylphenyl derivative(OTP) is found to be the best catalyst for the epoxidation of (E)-stilbeneand is tested for a range of other alkenes. Some ketone-derived iminium saltsare used for the first time as promoters of the epoxidation of (E)-stilbene instoichiometric amounts, with perchlorate (X) giving comparable results asOTP. Attempts to prepare chiral variants of these iminium salts are largelyunsuccessful, presumably due to their ready hydrolysis. — (ARMSTRONG,ALAN; AHMED, GHAFOOR; GARNETT, IAN; GOACOLOU, KATELL;WAILES, J. STEVEN; Tetrahedron 55 (1999) 8, 2341-2352; Dep. Chem., Univ.Nottingham, Nottingham NG7 2RD, UK; EN)

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