ENANTIOFACE DIFFERENTIATING ASYMMETRIC REACTION BY p-TOLYLSULFINYLCARBANION

Abstract

The enantioface differentiating reaction by p-tolylsulfinylcarbanion(2), derived from (+)-(R)-methyl p-tolyl sulfoxide (1), toward unsymmetrical ketones (3) is described. The carbanion(2) readily reacts with 3 to produce a mixture of (RSRC)- and (RSSC)-β-hydroxy sulfoxides (4). The ratio of the diastereoisomers in 4 and the absolute configuration of the predominant diastereoisomer were determined with the aid of NMR and the specific rotation of alcohol(6) which was prepared by desulfurization of 4.

C2-Symmetric Bissulfoxides as Organocatalysts in the Allylation of Benzoyl Hydrazones: Spacer and Concentration Effects

“…So, as a first comparative study we conducted the allylation of hydrazone 1 with trichloroallylsilane 2 using sulfoxide 4 , together with ( R , R )-bis-( p -tolylsulfinyl)methane 5 and ( R , R )-bis-( p -tolylsulfinyl)ethane 6 . Bissulfoxide 5 was obtained by condensation of lithiomethyl p -tolyl sulfoxide with ( S S )-menthyl p -toluenesulfinate, as pioneered by Kuneida . On the other hand, bissulfoxide 6 was obtained by Cu(I)-catalyzed dimerization of lithiomethyl p -tolyl sulfoxide, following a method developed some 30 years ago by Mislow .…”