Mn(III) complexes of chiral "salen" type ligands derived from carbohydrates in the asymmetric epoxidation of styrenes

A strategy for the synthesis of new chiral salen type ligands derived from α-d-glucose and α-d-mannose is described. The compounds were obtained by introducing appropriate functions at the C2 and C3 positions of the sugar ring. The efficiency of the complexes in the epoxidation of styrenes was also examined and shown to give good results, for example, cis-β-methylstyrene was functionalised with ee’s of up to 86%.