Photo-organocatalytic enantioselective alpha-hydroxylation of beta-keto esters and beta-keto amides with oxygen under phase transfer catalysis

摘要

An efficient and enantioselective photo-organocatalytic alpha-hydroxylation of beta-dicarbonyl compounds using molecular oxygen was extended. This simple catalytic procedure is applicable to a range of beta-keto esters and beta-keto amides (30 examples) with a new series of C-2'-substituted phase transfer catalysts in good enantiopurity (up to 90% ee) and yield (up to 99%). Moreover, the reaction was successfully scaled up to gram quantity without any loss of enantioselectivity.