Cobalt-Catalyzed Cross-Coupling of Glycosyl Sulfones with Zinc reagents toward the Stereoselective Synthesis of C(sp/sp2)-Glycosides

A cobalt-catalyzed desulfonylative cross-coupling of glycosyl sulfones with organozinc reagents toward the stereoselective synthesis of C-glycosides is reported. The new C-glycoside synthesis proceeds under mild reaction conditions and exhibits tolerance to a range of functional groups. Diverse alkynylated, arylated, and alkenylated products are formed with high efficiency and excellent diastereoselectivity. Mechanistic studies indicate a radical pathway.