The motif of two vicinal quaternary carbon centers is found in a wide range of bioactive natural products such as hyperolactones A–C [1] and (À)-biyouyanagin A [2](Scheme 1). The interesting biological activities and unique structures of these compounds have stimulated many total syntheses.[3] In general, the stereoselective construction of two vicinal quaternary carbon centers relys on substrate control. Only a few catalytic asymmetric CÀC ...
