Pd-catalyzed functionalization of benzo-2,1,3-thiadiazole at the C-5-position using 1-thiosugars

An efficient and unprecedented S -glycosylation reaction of benzo-2,1,3-thiadiazole at the C-5-position using a Pd-G 3 Xantphos palladacycle precatalyst has been described. This methodology showed a high functional group tolerance to the electrophilic partner and can be successfully applied to a variety of β-mono- and di-thiosugar derivatives. A series of thioglycoside derivatives from benzo-2,1,3-thiadiazole were prepared in good to excellent yields under mild and operationally simple reaction conditions. Structure modification of thioglycosides by cross-coupling reaction using aglycones with biological properties, such as AChE and angiotensin II inhibitors.