Diastereoselective alpha-Hydroxylation of N-tert-Butanesulfinyl Imidates and N'-tert-Butanesulfinyl Amidines with Molecular Oxygen

Diastereoselective alpha-hydroxylation using molecular oxygen has been achieved with chiral alpha-alkyl N-tert-butanesulfinyl imidates and alpha-aryl N'-tert-butanesulfinyl amidines. The aza-enolates generated from deprotonation of imidates/amidines can be intercepted by O-2 with excellent diastereocontrol and subsequently transformed into alpha-hydroxylation products in the presence of the reductant trimethyl phosphite.