Synthesis of planar chiral ferrocenyl sulfides and evaluation as catalysts for the asymmetric epoxidation of aldehydes

Abstract

New ferrocenyl sulfides, exhibiting planar chirality, have been prepared. They incorporate various heteroatom groups, and in some cases central chirality (sulfur or carbon). They were evaluated as catalysts for the asymmetric epoxidation of aldehydes via sulfonium ylides. A onepot reaction has been achieved, involving addition of benzaldehyde, benzyl bromide, 20% molar equivalent of the ferrocenyl sulfide, sodium iodide in a mixture of tert-butanol and water. Good yields of stilbene oxide were obtained, with enantiomeric excesses up to 53%.