Continuous organocatalytic flow synthesis of 2-substituted oxazolidinones using carbon dioxide

A polystyrene-supported 1,5,7-triazabicyclodec-5-ene (TBD) was used as a highly recyclable and stable catalyst for the conversion of epoxy amines into various 2-oxazolidone scaffolds. This approach combines the use of CO2 as an attractive, cheap and abundant C-1 source with a halide-free, organocatalytic continuous flow approach to promote the efficient synthesis of a small library of pharmaceutically relevant 2-substituted oxazolidinones, including the known drug Toloxatone. A packed bed reactor containing the same batch of immobilized catalyst could be applied for the continuous synthesis of a series of heterocyclic products over a two week period without significant changes in catalytic activity.