Glycosidation Silver trifluoromethanesulfonate

In relation to carbohydrate chemistry, the Koenigs-Knorr synthesis of glycosides involves the treatment of glycosyl halides with an alcohol or phenol in the presence of a heavy metal salt.267 Karrer268 discovered that reaction of silver salts of hydros acids could also be used and use of these reagents has been extended more recently. Numerous variations and improvements on the original method have now been reported, and silver oxide, silver carbonate or silver trifluoromethanesulfonate have since become the accepted standard reagents.267... 

The advances that have led to the almost routine synthesis of tri- and tetrasaccha-rides began in the early 1970s and included a new approach to a-glycosides, the halide-ion catalyzed glycosylation [4], and the introduction of improved heavy metal catalysts such as silver trifluoromethanesulfonate (triflate) [5]. Numerous other technical and conceptual advances punctuated the intervening period and reference to these developments are to be found in the cited literature of several reviews [6—9]. 

Banoub, J., Bundle, D. R. 1,2-Orthoacetate intermediates in silver trifluoromethanesulfonate promoted Koenigs-Knorr synthesis of disaccharide glycosides. Can. J. Chem. 1979, 57, 2091-2097. 

P. J. Garegg and T. Norberg, Observations on silver trifluoromethanesulfonate-promoted syntheses of 1,2-trans-glycosides from acylated glycosyl bromides, Acta Chem. Scand. B, 33 (1979) 116-118. 

SESCI in Synthesis. The SES group has been used successfully in the synthesis of glycosides (eq 5). Reaction of (6) with SES-sulfonamide and lodonium Di-sym-collidine Perchlorate provides the iodo sulfonamide (7) in 82% yield. Treatment of (7) with (benzyloxy)tributylstannane in the presence of Silver ) Trifluoromethanesulfonate provides the p-benzyl glycoside (8). Fluoride treatment of (8) removes both the silyl ether and the SES group, giving the amino alcohol (9). 

Glycosidation Allyl chloroformate, 9 Boron trifluoride etherate, 43 Silver(I) tetrafluoroborate, 273 Silver (I) trifluoromethanesulfonate, 274 Thallium zeolites, 296 Tin(II) trifluoromethanesulfonate, 301 Trichloroacetonitrile, 321 Grignard reactions and reactions of... 

Trichloroacetonitrile, 321 C-Glycosides Allyltrimethylsilane, 11 Organoaluminum reagents, 202 Silver(I) trifluoromethanesulfonate,... 

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