Iron-Catalyzed Diastereoselective Synthesis of Disubstituted Morpholines via C-O or C-N Bond Formation

Abstract

The diastereoselective synthesis of 2,6- and 3,5-disubstituted morpholines was achieved from 1,2-amino ethers and 1,2-hydroxy amines substituted by an allylic alcohol using an iron(III) catalyst. The morpholines were obtained either by C-O or C-N bond formation. A plausible mechanism is suggested, involving a thermodynamic equilibrium to explain the formation of the cis diastereoisomer as the major product.