Dynamic Kinetic Asymmetric Ring-Opening/Reductive Amination Sequence of Racemic Nitroepoxides with Chiral Amines: Enantioselective Synthesis of Chiral Vicinal Diamines

We
report a highly diastereoselective synthesis of vicinal diamines by
the treatment of nitroepoxides with primary amines and then a reducing
agent. When using a chiral primary amine, racemic nitroepoxides are
transformed into chiral diamines as a single enantiomers (>95:5
er) through a dynamic kinetic asymmetric transformation (DYKAT). The
overall process is a one-pot procedure combining the exposure of nitroepoxides
to chiral amines to afford diastereomeric mixtures of aminoimines
and subsequent stereoselective imine reduction.