113965-65-4Relevant academic research and scientific papers
Stereoselection parameters and theoretical model in the enantioselective protonation of enolates with α-sulfinyl alcohols
Asensio, Gregorio,Aleman, Pedro,Gil, Jesus,Domingo, Luis R.,Medio-Simon, Mercedes
, p. 9342 - 9347 (1998)
The effects of the solvent, temperature, presence of lithium salts in the medium, and acidity of the proton source on enantioselective protonation with α-sulfinyl alcohols 2a-e were studied stereoselectivity was generally enhanced when lithium bromide was present in the medium during enolization and also with the use of methylene chloride solutions. Conversely, the optimal reaction temperature varied with the α-sulfinyl alcohol used as a proton source, and its effect appears to be related to both the acidity of the proton source and the enolate structure. α-Sulfinyl alcohols 2a and 2b gave the best results when the reactions were carried out at -100 °C, while the optimal temperature with 2c was -78 °C. The same ee values were obtained with 2d and 2e at either -100 or -78 °C. In addition, an efficient synthesis of α-sulfinyl alcohols 2b and 2c is described.
Synthesis of (Rc,Ss)-1,1,1-trifluoro-3-(p-molylsulfinyl)-2-propanol by an asymmetric reduction with a yeast, Yamadazyma farinosa, as a key-step
Sakai, Atsushi,Bakke, Mikio,Ohta, Hiromichi,Kosugi, Hiroshi,Sugai, Takeshi
, p. 1255 - 1256 (2007/10/03)
(Rc,Ss)-1,1,1-trifluoro-3-(p-tolysulfinyl)-2-propanol (>99% e.e.), an important reagent for the asymmetric protonation of substituted enolates, was prepared (70%) from (S)-methyl p-tolyl sulfoxide. The stereoselectivity of the Yamdazyma farinosa-catalyzed
β-HYDROXY SULFOXIDE DERIVATIVES AS A POWERFUL CHIRAL PROTONATING REAGENT
Kosugi, Hiroshi,Hoshino, Kunihide,Uda, Hisashi
, p. 401 - 402 (2007/10/02)
Highly enantioselective protonation of prochiral lithium enolates using enantiomerically pure β-hydroxy sulfoxides are described.
Homochiral Perfluoroalkyl-Group-Substituted Secondary Alcohols Through Stereoselective Reduction of Perfluoroalkyl 1-(p-Tolylsulfinyl)alkyl Ketones
Bravo, Pierfrancesco,Frigerio, Massimo,Resnati, Giuseppe
, p. 955 - 960 (2007/10/02)
The reduction of some enantiomerically pure perfluoroalkyl α-(p-tolylsulfinyl) ketones was performed.Alcohols containing perfluoroalkyl and p-tolylsulfinyl groups were obtained with high diastereoselection when a phenyl residue was present on the sulfinylated carbon and with lower diastereoselection in the other cases.Removal of the chiral sulfinyl group from single diastereoisomers gave secondary alcohols containing a perfluoroalkyl group in enantiomerically pure form.
Highly Stereoselective Asymmetric Michael Addition Reactions Employing (R;E)-3,3,3-Trifluoroprop-1-enyl p-Tolyl Sulphoxide
Yamazaki, Takashi,Ishikawa, Nobuo,Iwatsubo, Hitoshi,Kitazume, Tomoya
, p. 1340 - 1342 (2007/10/02)
(R;E)-3,3,3-Trifluoroprop-1-enyl p-tolyl sulphoxide, prepared in three steps from ethyl trifluoroacetate, showed a high degree of diastereoselectivity in Michael addition reactions with enolates; by this means, optically active trifluoromethylated organic molecules can be obtained readily in high yield as well as in high optical purity.
