Preparation of sugar-derived 1,2-diamines via indium-catalyzed aza-Henry-type reaction: application to the synthesis of 6-amino-1,6-dideoxynojirimycin

The combination of (p-methoxyphenyl)imine, a bromonitroalkane, and zinc in the presence of catalytic indium allows straightforward access to β-nitroamine derivatives. The use of chiral sugar-derived imines furnished the corresponding β-nitroamines in high yields and stereoselectivities, from which the corresponding 1,2-diamines were easily obtained. The synthetic utility of the sugar-derived 1,2-diamines in the preparation of iminosugars was illustrated in a concise synthesis of 6-amino-1,6-dideoxynojirimycin.