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

Article abstract of DOI:10.1016/S0040-4020(02)01294-2

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 CH₂Cl₂ 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.