Abstract
A route to 1,2-diols by the direct organocatalytic enantioselective alpha-oxidation of aldehydes using molecular oxygen is presented. Protected commercially available chiral pyrrolidines catalyze the asymmetric alpha-oxidation of aldehydes with singlet molecular oxygen with high enantioselectivity to furnish the corresponding diols after in situ reduction in high yield with up to 98% ee. Electrophilic singlet molecular oxygen was photo or chemically generated ('dark' O-1(2)). (c) 2006 Elsevier Ltd. All rights reserved.