Asymmetric desymmetrization of meso-pyrrolidine derivatives by enantiotopic selective CH hydroxylation using (salen)manganese(III) complexes

✍ Scribed by T. Punniyamurthy; Tsutomu Katsuki

• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 1005 KB
• Volume: 55
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(99)00518-9

✦ Synopsis

Chiral (salen)manganese(IlI) complexes 1 catalyzed the asymmetric clesymmetrization of Nprotected meso-pyrrolidine derivatives 3, 6-8, 15 and 18 by enantiotopic selective C-H oxidation in the presence of term~aal oxidant iodo~ylbenzene. The oxidation occurred chemoselectively at the carbon ct to the nitrogen atom to afford optically active hydroxypyrrolidine derivatives 9, 11, 13, 16, 19 and 21 that were further oxidized to chiral lactams with Jones reagent. The N-protecting groups of the meso.

pyrrolidine derivatives have notable effect on the enanfioselectivity.