Asymmetric, anti-selective scandium-catalyzed Sakurai additions to glyoxyamide.: Applications to the syntheses of N-Boc D-alloisoleucine and D-isoleucine

An enantio- and diastereoselective Sakurai-Hosomi reaction, catalyzed by chiral scandium pyridyl-bis(oxazoline) (pybox) complexes, has been developed. Both alkyl- and aryl-substituted allylsilanes are effective coupling partners with N-phenylglyoxamide. Applications of this reaction to the asymmetric syntheses of N-BOC D-alloisoleucine and D-isoleucine are described.