Cobalt-Catalyzed Highly α-Stereoselective Glycosylation of Glycals

Following the satisfactory catalytic performance of cobalt in the C-glycosylation of glycals, further study of cobalt's application values was performed under mild conditions, leading to a range of highly alpha-stereoselective 2,3-unsaturated O-, S-, and N-glycosides. The synthetic potential of the developed protocol was underscored by the late-stage functionalization of pharmaceutically relevant molecules including the canagliflozin derivative (a potential candidate for treating type 2 diabetes and alleviating pathological aging). Furthermore, control experiments were conducted to elucidate a reasonable mechanism and rule out the pathway involving the configuration conversion between alpha- and beta-anomers.