β-Configured 2-deoxy glycosides are integral components in various biologically active natural products (Fig- ). The most conceptually straightforward approach to the synthesis of β-2-deoxyglycosides involves stereospecific invertive displacement of appropriate and often readily available α-configured glycosyl electrophiles. However, these electrophiles are highly prone to inherently αselective non-stereospecific SN1-like pathways due to the electron-rich nature of the site of nucleophilic substitution relative to fully oxygenated analogs (Figure ). As such, application of otherwise β-selective glycosylation protocols to 2-deoxyglycosylations has proven challenging, and the synthesis of 2-deoxy-β-glycosides has remained a long-standing challenge in the field. The Bennett group devised a strategy of in situ generation of α-glycosyl sulfonates and stereospecific displacement by strongly nucleophilic potassium alkoxides, allowing the synthesis of β-linked 2-deoxyoligosaccharides and 2-deoxyglycoside natural products. However, the need for strongly basic conditions limited its application with basesensitive functionalities. Li and coworkers developed a directing-group strategy with trimethylsilyl trifluoromethanesulfonate catalysis. Excellent β-selectivities were obtained, but the requirement for a strongly Lewis acidic catalyst renders the method incompatible with Lewis-basic functionalities. An alternative strategy, reported by Niu and coworkers, employs palladium catalysis to achieve stereo-and chemoselective 2-deoxy glycosylations of phenols across a remarkable scope of nucleophiles and electrophiles. This notable advance in functionalgroup-compatible 2-deoxy glycosylations notwithstanding, a mild and general protocol for the 2-deoxy-β-glycosylation of both phenols and alcohols remains elusive. Other methods, including umpolung strategies, C-2 auxiliaries, boronic acid catalysis, supramolecular capsules, and acid-catalyzed substitutions at cryogenic temperatures, which similarly lack generality in nucleophile scope or require multi-step protocols. (C) The approach to catalytic, β-selective 2-deoxy and 2,6dideoxyglucosylations presented herein.