<scp>2?Diphenylphosphinoyl</scp> ?acetyl as a Remote Directing Group for the Highly Stereoselective Synthesis of <scp>??Glycosides</scp>

The configuration of the anomeric glycosidic linkages is crucial for maintaining biological functions and activities carbohydrate molecules. However, their stereochemistry control in glycosylation represents one most challenging tasks chemistry. In this report, easily accessible 2-diphenylphosphinoyl-acetyl (DPPA) group was developed as a highly stereodirecting catalytic via hydrogen-bond mediated delivery alcoholic acceptors. TMSOTf-catalyzed with DPPA-installed glycosyl imidate donors displayed excellent ?-selectivities broad substrate scope, particularly practical to synthesize ?-configured 2-deoxy 2-azido-2-deoxy glycosides from poor acceptors suffering electron-deficiency, steric hindrance, structural rigidity. Chemoselective removal DPPA could be readily achieved under mild catalysis Ni(OTf)2 without affecting acid- or base-labile functional groups, facilitating rapid conversion biologically important molecules such uronic acids 2,6-deoxy glycosides. application DPPA-directed further highlighted complex synthesis toward saponin dioscin using 2,4-O-glycosylated donor convergent manner. Appendix S1: Supporting Information Please note: publisher not responsible content functionality any supporting information supplied by authors. Any queries (other than missing content) should directed corresponding author article.