Oxidation of prochiral sulfides with chiral dioxirane

Enantioselective Synthesis of Sulfoxides: 2000−2009

“…Low enantioselectivity (2-26% ee) and moderate yields (47-60%) were observed when chiral dioxirane 152 generated in situ from pyranose-derived ketone was used for the oxidation of alkyl aryl sulfides. 229 These examples, and the previous attempts with chiral peracids (up to 20% ee) [230][231][232] and N-chlorocaprolactam (ee below 3%) 233 clearly show that although, in principle, each organic oxidant can be converted into a nonracemic derivative, the asymmetric induction can be disappointingly inefficient. As a result, chiral oxaziridines remain unrivaled in the field of metal-free enantioselective sulfoxidation.…”

“…Thioanisole was almost quantitatively (90−92% yield) converted into the S-oxide by these chiral oxidants, but the ee was rather unsatisfactory (11−16%). Low enantioselectivity (2−26% ee ) and moderate yields (47−60%) were observed when chiral dioxirane 152 generated in situ from pyranose-derived ketone was used for the oxidation of alkyl aryl sulfides . These examples, and the previous attempts with chiral peracids (up to 20% ee ) − and N -chlorocaprolactam ( ee below 3%) clearly show that although, in principle, each organic oxidant can be converted into a nonracemic derivative, the asymmetric induction can be disappointingly inefficient.…”

Three‐Membered Heterocycles. Structure and Reactivity

“…The same diastereomeric bias was observed even with the opposite epoxide stereochemistry, which seems to point toward a pivotal role of the a-substituent. Enantioselective sulfoxidation using chiral ketone precursors appears promising [828], although results are highly variable and substrate-dependent.…”

Dioxiranes: a half-century journey

“…88 In 2006, Dieva and co-workers demonstrated the asymmetric oxidation of prochiral sulfides using chiral dioxirane; the corresponding chiral sulfoxides were isolated in ∼6-25% ee. 89 In 1990, the Tabuchi group treated thioketone 86 with in situ generated 9 and obtained S-oxygenated product 87 in 29% yield along with adamantanone (Scheme 20a). 90,91 Conversely, when 9 (1 equiv.)…”

“…88 In 2006, Dieva and co-workers demonstrated the asymmetric oxidation of prochiral sulfides using chiral dioxirane; the corresponding chiral sulfoxides were isolated in ∼6–25% ee. 89…”