Organocatalytic synthesis of chiral tetrasubstituted allenes from racemic propargylic alcohols.

ABSTRACT: Although chiral allene preparation via formal S_N2' nucleophilic substitutions of enantioenriched propargylic derivatives or metal-catalyzed reactions of racemic propargylic derivatives has attracted considerable attention and found applications in many areas of research, direct use of propargylic alcohols instead of propargylic derivatives for catalytic asymmetric allene synthesis is unknown. Here, we show that a highly enantioselective synthesis of tetrasubstituted allenes from racemic propargylic alcohols has been realized by organocatalysis with good efficiency (up to 96% yield and 97% ee). The intermolecular C-C and C-S bond formation was achieved efficiently with simultaneous stereocontrol over the axial chirality. Furthermore, an adjacent quaternary stereocenter could also

SUBMITTER: Qian D 

PROVIDER: S-EPMC5603569 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature