Bismuth(iii) triflate as a novel and efficient activator for glycosyl halides

Abstract

Presented herein is the discovery that bismuth(III) trifluoromethanesulfonate (Bi(OTf)3) is an effective catalyst for the activation of glycosyl bromides and glycosyl chlorides. Bi(OTf)3 works well in promoting the glycosidation of...

Synthesis and Glycosidation of Anomeric Halides: Evolution from Early Studies to Modern Methods of the 21st Century

“…Recently, Demchenko and co-workers have shown an efficient activation of glycosyl halides in the presence of Bi­(OTf) 3 . Compared to most common metal salt activators of glycosyl halides wherein stoichiometric amount of activators is needed, a rapid activation of glycosyl bromides was achieved in the presence of 0.35 equiv of Bi­(OTf) 3 .…”

“…As a result, glycosidation of benzoylated and benzylated galactosyl bromides 40 and 41 with glycosyl acceptor 36 in the presence of Bi­(OTf) 2 (0.35 equiv) afforded respective galactosides 78 and 79 in good yields (Scheme ). An effective glycosylation of a variety of glycosyl acceptors was achieved for sugars of the gluco, manno, rhamno, and glucosamino series equipped with different protecting groups …”

“…In 2021, Demchenko and co-workers have developed very mild reaction conditions for the activation glycosyl chlorides in the presence of bismuth­(III) triflate . This reaction worked similarly to that of glycosylation with glycosyl bromides.…”

“…251 Recently, Demchenko and co-workers have shown an efficient activation of glycosyl halides in the presence of Bi(OTf) 3 . 308 Compared to most common metal salt activators of glycosyl halides wherein stoichiometric amount of activators is needed, a rapid activation of glycosyl bromides was achieved in the presence of 0.35 equiv of Bi(OTf) 3 . Due to the detrimental effect of strongly acidic TfOH produced as a byproduct, the authors have increased the amount of molecular sieves and identified nitromethane-DCM as the preferred reaction solvent.…”

Bismuth-Catalyzed Stereoselective 2-Deoxyglycosylation of Disarmed/Armed Glycal Donors

“…Despite the significant insights, the selective activation of “disarmed” and “armed” glycals to generate atom-economical 2-deoxyscaffolds is scarcely investigated. , We conceptually envisioned that a post-transition metal-oxo-species such as Bi­(OTf) 3 would allow the coordination of donor–acceptor affirmatively by the [Bi­(III)–(glycal)–(RO–H)] complex and would likely activate the electron-deficient double bond in “disarmed” glycals. Despite the appreciated air/moisture/light stability and nontoxic, inexpensive, and reversible hydrolysis characteristics, synthetic versatility of the Bi­(III)-catalyst as a greener reagent is under-investigated in glycochemistry …”