Enantioselective Synthesis of Functionalized Quaternary Stereocenters

An enantioselective synthesis of functionalized quaternary stereocenters was developed from amino alcohol derived (bromoalkylidene)morpholinones. Stereoselective cross-coupling of the morpholinones with arylboronic acids or alkyl trifluoroborates provided a variety of disubstituted alkylidenemorpholinones. A highly stereoselective Prins reaction of the cross-coupling products generated the target quaternary stereocenter. The Prins products are readily converted into a variety of acyclic, enantiomerically enriched, functionalized building blocks with a quaternary stereocenter.