No abstract

Flash chromatography on silica gel of several sulfoxides of varying ee's shows a strong enantiomeric fractionation. For example (R)-methyl p-tolyl sulfoxide of 86% ee gives 99% ee (R) in the first fraction and 63 % ee (R) in the last fraction, respectively, while (fi)-ferrocenyl phenyl sulfoxide (65 % ee) provides (S) enantiomer (79% ee) in the first fraction and (R) enantiomer (94% ee) in the last fraction. Various aspects of the phenomena are discussed. This method provides a simple procedure to obtain high ee for sulfoxides prepared by asymmetric synthesis of only modest enantioselectivity.Chiral sulfoxides are extremely useful chiral auxiliaries in asymmetric synthesis.1-4 For this purpose, it is of interest to prepare sulfoxides of various structural types. The conversion of chiral sulfinates to sulfoxides

No abstract

The first use of the NH S-trifluoromethyl sulfoximine as an ortho directing group is described for the functionalization of the aryl group bonded to the sulfur atom. Various electrophiles (halogen, carbon, oxygen, sulfur, boron, etc.) are introduced on the aromatic ring. Cyclic S-trifluoromethyl sulfoximines are synthesized either with properly chosen electrophiles or by structural adjustment of o-azido sulfoximines. Fluorinated analogues of prazosin are also prepared.