Asymmetric synthesis of phenyl alkyl sulphoxides via the non-destructive mediation of the chiral iron acyl [(η5-C5H5)Fe(CO)(PPh3)COCH2Me]

Abstract

The chiral sulphoxide (RSS)-[(η⁵-C₅H₅)Fe(CO)(PPh₃)COCHMeSOPh] can be efficiently and stereoselectively prepared from (R)-[(η⁵-C₅H₅)Fe(CO)(PPh₃)COCH₂Me]via the asymmetric oxidation of the corresponding sulphide: treatment of (RSS)-[(η⁵-C₅H₅)Fe(CO)(PPh₃)COCHMeSOPh] with lithium dialkylcuprates afforded phenyl alkyl sulphoxides and regenerated (R)-[(η⁵-C₅H₅)Fe(CO)(PPh₃)COCH₂Me], while oxidative decomplexation led to (SS)-PhCH₂NHCOCHMeSOPh; all the products were essentially enantiomerically pure.