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 α-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 α- and β- anomers.