An efficient and unprecedented palladium‐catalyzed S‐glycosylation reaction of a range of alkenyl and alkynyl halides by using thiosugars as nucleophile partners has been established. With palladium diacetate in combination with Xantphos as the catalytic system, a variety of β‐alkenylthioglycosides as well as β‐alkynylthioglycosides can be prepared in good to excellent yields. The efficiency of this general protocol was well‐demonstrated by the formal synthesis of a leaf‐closure β‐glucosidase inhibitor.
