Mild and efficient synthesis of 5,6-diamino-5,6-dideoxy-1,2- O-isopropylidene-3- O-methyl-β- l-idofuranose: precursor of the first carbohydrate-derived chiral Mn(III)–salen complex

Abstract

Carbohydrates as multifunctional naturally occurred chiral products were used for the first time as chiral building blocks in Mn(III)–salen complexes as catalysts for the enantioselective epoxidation of alkenes. The pathways of the mild and efficient synthesis of a Mn(III)–salen complex and its diamino precursor 5,6-diamino-5,6-dideoxy-1,2- O-isopropylidene-3- O-methyl-β- l-idofuranose starting from d-(+)-glucose are described. The complex efficiently catalyzed the epoxidation of styrene and 1,2-dihydronaphthalene, using aqueous sodium hypochlorite in CH 2Cl 2 as terminal oxidant. The enantiomeric excesses were 13 and 33%, respectively. Mn(III)–salen catalyst with only one stereogenic carbon atom that is adjacent to nitrogen atom proved to be able to show enantioselectivity.