Bisguanidinium-catalyzed formation of oxygen-containing quaternary stereogenic carbon centers

Abstract

We report bisguanidinium-catalyzed enantioconvergent halogenophilic substitution reactions (S_N2X) that lead to the formation of C(sp³)–O bonds using racemic tertiary bromides with hydroxylamides or phenols as nucleophiles. These approaches gave direct access to a series of oxygen-containing quaternary stereogenic carbon centers, which are common moieties in bioactive compounds. We also demonstrated the utility of these methodologies through concise syntheses of enantiopure bicalutamide and chiral fibrates.