Stereocontrolled α-Galactosylation under Cooperative Catalysis
作者:Melanie Shadrick、Yashapal Singh、Alexei V. Demchenko
DOI:10.1021/acs.joc.0c01279
日期:2020.12.18
A recent discovery of a cooperativecatalysis comprising a silver salt and an acid led to a dramatic improvement in the way glycosyl halides are glycosidated. Excellent yields have been achieved, but the stereoselectivity achieved with 2-O-benzylated donors was poor. Reported herein is our first attempt to refine the stereoselectivity of the cooperativelycatalyzed galactosylation reaction. Careful
targets due to their abundance in natural oligosaccharides involved in many biological processes. Nevertheless their preparation is hampered by several issues, due to both the strictly anhydrous conditions typically required in glycosylation procedures and the non-trivial achievement of high α-stereoselectivity, one of the major challenges in oligosaccharidesynthesis. In this paper we report a novel and