Catalytic Asymmetric Oxidation oftert-Butyl Disulfide. Synthesis oftert-Butanesulfinamides,tert-Butyl Sulfoxides, andtert-Butanesulfinimines
Citations Over TimeTop 1% of 1998 papers
Abstract
The first example of the catalytic asymmetric oxidation of tert-butyl disulfide (1) is described. The product, tert-butyl tert-butanethiosulfinate (2) is obtained with 91% enantiomeric excess in yields of ≥92% on scales as large as 1 mol. The application of H2O2 as stoichiometric oxidant in the presence of 0.25 mol % of VO(acac)2 and 0.26 mol % of a chiral Schiff base ligand, 6a, is both convenient and cost-effective. Thiosulfinate ester 2 is chemically and optically stable and serves as an excellent precursor to chiral tert-butanesulfinyl compounds by the stereospecific nucleophilic displacement of tert-butyl thiolate. Addition of LiNH2 in liquid ammonia and THF provides tert-butanesulfinamide (3; 91% yield). A single recrystallization provides enantiomerically pure 3 in 71−75% overall yield from disulfide 1. Enantiomerically pure thiosulfinate ester 2 also reacts readily and stereospecifically with Grignard reagents, organolithiums, lithium amides, and lithium imine salts to provide enantiomerically pure chiral sulfoxides, sulfinamides, and sulfinimines in good yield.
Related Papers
- → NHC-Catalyzed Transformation Reactions of Imines: Electrophilic versus Nucleophilic Attack(2022)32 cited
- → Stereospecific Electrophilic Fluorination of Alkylcarbastannatrane Reagents(2017)23 cited
- → Enantiomeric enrichment by the use of density differences between racemic compounds and optically active enantiomers(1995)16 cited
- → Stereospecific Electrophilic Fluorination of Alkylcarbastannatrane Reagents(2017)5 cited
- → Colour indicator for enantiomeric excess and assignment of the configuration of the major enantiomer of an amino acid ester(2002)26 cited