Diastereoselective Addition of PhSCF<inf>2</inf>SiMe<inf>3</inf>to Chiral N- tert-Butanesulfinyl Ketimines Derived from Isatins: Synthesis of Enantioenriched gem-Difluoromethylenated Spiro-pyrrolidinyl and Spiro-piperidinyl Oxindoles
Journal of Organic Chemistry Vol.87 No.23 (2022) , 15963-15985
Suggested Citation
Keereewan S., Kuhakarn C., Leowanawat P., Saithong S., Reutrakul V., Soorukram D. Diastereoselective Addition of PhSCF<inf>2</inf>SiMe<inf>3</inf>to Chiral N- tert-Butanesulfinyl Ketimines Derived from Isatins: Synthesis of Enantioenriched gem-Difluoromethylenated Spiro-pyrrolidinyl and Spiro-piperidinyl Oxindoles. Journal of Organic Chemistry Vol.87 No.23 (2022) , 15963-15985. 15985. doi:10.1021/acs.joc.2c02098 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/84136
Title
Diastereoselective Addition of PhSCF<inf>2</inf>SiMe<inf>3</inf>to Chiral N- tert-Butanesulfinyl Ketimines Derived from Isatins: Synthesis of Enantioenriched gem-Difluoromethylenated Spiro-pyrrolidinyl and Spiro-piperidinyl Oxindoles
A convenient and efficient synthetic strategy to prepare enantioenriched gem-difluoromethylenated spiro-pyrrolidinyl and spiro-piperidinyl oxindoles is described. Fluoride-mediated diastereoselective nucleophilic addition of PhSCF2SiMe3to chiral N-tert-butanesulfinyl ketimines derived from isatins was a key step and provided diastereomeric adducts, which were readily separable. Removal of the chiral sulfinyl group followed by structural manipulation afforded chiral gem-difluoromethylenated spiro-pyrrolidinyl and spiro-piperidinyl oxindoles.
