A simple and versatile method for the enantio- and diastereoselective synthesis of mono- or disubstituted 3-aminoazepanes is described. The key step involves a highly regio- and diastereoselective tandem ring-enlargement/alkylation or reduction process. This novel synthetic route provides enantiomerically pure constrained diamines interesting as scaffolds for medicinal chemistry.
Syntheses of optically pure 2-aryl-3-aminoazepanes derived from 2-cyano 6-oxazolopiperidine are described. The key step involves a one-pot reduction and ring-enlargement process occurring in a highly regio- and stereoselective way.