Organocatalytic Enantioselective and Diastereodivergent Mannich Reactions of 5‐Substituted Oxazolidin‐2,4‐Diones

Abstract

The first catalytic asymmetric Mannich reaction of 5‐substituted oxazolidine‐2,4‐diones is reported. By using an L‐tert‐leucine‐derived thiourea‐tertiary amine as catalyst, a variety of valuable oxazolidine‐2,4‐ones bearing a quaternary stereocenter at the 5‐position and an adjacent aza‐tertiary stereocenter at the α‐position of the heterocycles were obtained in high enantio‐ and diastereoselectivities. Meanwhile, exploiting an L‐tert‐leucine‐derived dipeptide‐based thiourea‐amide‐tertiary amine catalyst could switch diastereoselectivity, delivering the corresponding diastereomers with good to excellent enantioselectivities.