Abstract
Chemical synthesis of certain glycosaminoglycans like hyaluronic acid and chondroitin sulfate has long been challenging due to critical synthetic intermediates lacking in reactivity and inhibiting stereoselectivity. New methodology for the stereoselective formation of 1,2-trans-β glycosidic bonds via catalysis with a hemin-derived iron porphyrin triflate complex has been developed, allowing for the use of hindered secondary glycosyl acceptors and electron deficient glycosyl donors. This expanded substrate scope has made hyaluronic acid and chondroitin sulfate not only synthetically accessible but capable of rapid assembly with several glycosylations. Herein, syntheses of disaccharide components for hyaluronic acid and chondroitin sulfate syntheses via iron-catalyzed 1,2-trans-β-selective glycosylation is reported, alongside progress towards tetrasaccharide syntheses.