82679-83-2Relevant academic research and scientific papers
ASYMMETRIC OXIDATION OF ACHIRAL SELENIDES TO OPTICALLY ACTIVE SELENOXIDES. STEREOCHEMISTRY OF THE ALLYL SELENOXIDE-SELENENATE SIGMATROPIC REARRANGEMENT
Davis, Franklin A.,Stringer, Orum D.,McCauley, John P., Jr.
, p. 4747 - 4758 (2007/10/02)
Asymmetric oxidation of methyl phenyl selenide (3), under anhydrous conditions, by chiral 2-sulfonyloxaziridines, 1-2, give optically active methyl phenyl selenoxide (8.1-9.3percent ee).The stereochemistry of the selenoxide is determined by the configuration of the oxaziridine three membered ring with nonbonded steric interactions responsible for the chiral recognition.Asymmetric oxidation of E-phenyl cinnamyl selenide (7) by 1-2 affords optically active 1-phenylallyl alcohol (9).A concerted sigmatropic rearrangement via an exo transition state is proposed.
Chemistry of Oxaziridines. 3. Asymmetric Oxidation of Organosulfur Compounds Using Chiral 2-Sulfonyloxaziridines
Davis, Franklin A.,Jenkins, Robert H.,Awad, Sami B.,Stringer, Orum D.,Watson, William H.,Galloy, Jean
, p. 5412 - 5418 (2007/10/02)
Chiral 2-sulfonyloxaziridines, 9-12, afford the best enantioselectivity of any chiral oxidizing reagent for the asymmetric oxidation of sulfides and disulfides to sulfoxides and thiosulfinates, respectively, 5-8 times better than chiral peracids.For asymmetric oxidations using 9-12, the configuration of the oxaziridine three-membered ring was shown to control the configuration of the product, which could be predicted using a chiral recognition mechanism (Figure 2).The increased asymmetric bias exhibited by chiral 2-sulfonyloxaziridines was attrbuted to the fact that the active-site oxygen was incorporated into a rigid chiral environment.The group size difference (GSD) effect in both the oxaziridine and substrate play important roles in determining the absolute configuration of the product and the magnitude of the asymmetric bias.As the GSD increases the enantioselectivity increases.
