Formation of substituted 2-iminooxazolidines via intermolecular 1,2-addition/intramolecular N-vinylation using 3-substituted-2-bromo-2-propen-1-ols as substrates

The Cu₂O-catalyzed reaction between equimolar amounts of easily available 3-substituted-2-bromo-2-propen-1-ols and dicyclohexyl carbodiimide in DMSO at 100?°C using K₃PO₄ as the base and in the absence of any additive exclusively delivers substituted 2-iminooxazolidines with yields up to 80%. The highly selective transformation is assumed to start with an intermolecular 1,2-addition, which is followed by an intramolecular N-vinylation. The products can also be obtained in the absence of Cu₂O, albeit in lower yields.