Organocatalytic asymmetric conjugate addition of diaryloxazolidin-2,4-diones to nitroolefins: an efficient approach to chiral α-aryl-α-hydroxy carboxylic acids

Abstract

The first catalytic asymmetric conjugate addition of diaryloxazolidin-2,4-diones to nitroolefins is described. By employing an L-threonine-based tertiary amine-urea as the catalyst, the reaction proceeded in an excellent enantio- and diastereoselective manner (up to >99% ee and >19 : 1 dr). The adducts could be conveniently transformed to valuable α-aryl-α-hydroxy carboxylic acids, which structurally feature two adjacent hetero-quaternary and tertiary stereogenic centers.