Asymmetric induction in the inter- and intramolecular radical carbon-carbon bond forming reactions of N-arylsulfonyl-alpha-bromocarboxamides with chiral ligands: the use of chiral sulfoxide ligands in radical chemistry

Inter- and intramolecular asymmetric radical carbon-carbon bond-forming rea ctions of sulfonamides were successfully achieved using chiral ligands in t he presence of Lewis acids. The use of chiral sulfoxides as chiral ligands in the radical reactions of sulfonamides provided higher enantioselectivity , proceeding through a diastereomerically more favorable intermediate, pres umably by enantiotopically selective coordination of one of the two oxygen atoms of the sulfonamides. (C) 2000 Elsevier Science Ltd. All rights reserv ed.