Investigation of Coupling Reactions for the Synthesis of Valienamine Pseudodisaccharides

Abstract

Amine-linked pseudodisaccharides based on valienamine were synthesised by C-N bond-forming reactions between valienol-derived C-1 electrophiles and carbohydrate nitrogen nucleophiles. Palladium-catalysed coupling with trichloroacetimidate leaving groups, Mitsunobu reactions with a nosylamide nucleophile, and alkylation of amines by C-1 bromides were investigated.

Amine-linked diglycosides: Synthesis facilitated by the enhanced reactivity of allylic electrophiles, and glycosidase inhibition assays

“…The trichloroacetimidate is a leaving group that has the advantage of being easily and stereospecifically synthesised from the alcohol under basic conditions. We recently used the trichloroacetimidate as leaving group in palladium catalysed synthesis of carbasugar pseudodisaccharides [ 36 ]. Treatment of the imidate 23 with an amine nucleophile 5 [ 33 ] and a palladium catalyst [ 21 ] resulted in the formation of four products, 24 (44%), 25 (15%), 26 (5%) and 27 (6%), which were assigned the structures given in Scheme 5 .…”