Catalytic asymmetric oxidation of sulfides using (salen)manganese(III) complex as a catalyst

✍ Scribed by Kenji Noda; Naoki Hosoya; Ryo Irie; Yuji Yamashita; Tsutomu Katsuki

• Publisher: Elsevier Science
• Year: 1994
• Tongue: French
• Weight: 667 KB
• Volume: 50
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)85529-0

✦ Synopsis

A6structz Asymmetric oxidation of sulfkles was examined by using (salen)mangane&III) complexes as catalysrp and (8S,8'S,l"S,2"S)-complex (2b) was found to show high asymmetric induction up to 90% ee. Its diastercom * (8R.8'R.l"S.2"S)-complex (la) that showed excellent asymmetric induction in the epoxidation of simple olez however. was a poor catalyst for the oxidation of sulfides. Kinetic resolution of racemic methyl phenyl sulfoxide with 2b was not effective.

Asymmetric oxidation of sulfides is one of current topics, since optically active sulfoxides am of high synthetic use as chiral synthons or as chiral auxiliaries and many useful methodologies for this purpose have been reported to date.1~213) For example, reactions using optically active oxaziridines as oxidant& or a r-butyl hydroperoxidefli(OPr-i)d/dialkyl tar&ate&O systemz) show high enantioselectivity (>90% ee.) but these reactions require a stoichiometric amount of chiral oxidant or catalyst. Recently Uemura et al. repOrted the catalytic formation of highly optically pure sulfoxides (up to 96% ee) by concomitantly performing enantioselective oxidation of sulfides and kinetic resolution of the resulting enantiomerically enriched sulfoxides with titanium-binaphthol complex as a catalyst. 3b) However, there is still no good methodology for yielding highly optically pure sulfoxides only by catalytic asymmetric oxidation of sulfides. On the other hand, it is well known that methodologies for asymmetric epoxidation are also useful ones for asymmetric oxidation of sulfides. Many optically active metalloporphyrins have, for example, been used as catalysts for asymmetric epoxidation and for asymmetric oxidation of sulfides.2) Recently optically active Scheme 1