Details

Autor(en) / Beteiligte

• van Well, Renate M.
• Kärkkäinen, Tiina S.
• Kartha, K.P. Ravindranathan
• Field, Robert A.

Titel

Contrasting reactivity of thioglucoside and selenoglucoside donors towards promoters: implications for glycosylation stereocontrol

Ist Teil von

• Carbohydrate research, 2006-07, Vol.341 (10), p.1391-1397

Ort / Verlag

Netherlands: Elsevier Ltd

Erscheinungsjahr

2006

Quelle

MEDLINE

Beschreibungen/Notizen

• The stereochemical outcome of glycosylation reactions with model thioglycosides and selenoglycosides proved to be dependent on the source of promoter iodonium ion, with iodine giving different results to N-iodosuccinimide (NIS) alone or N-iodosuccinimide/trimethylsilyltrifluoromethanesulfonate (NIS/TMSOTf). In contrast to armed thioglycosides, which anomerise, and disarmed thioglycosides, which do not react, both armed and disarmed selenoglycosides give rise to the corresponding glycosyl iodides when reacted with iodine. Further, whilst the single electron transfer agent DDQ alone is an ineffective promoter, in combination with iodine it produces better acetonitrile-assisted β-stereoselectivity with both thioglycosides and selenoglycosides than does tris(4-bromophenyl)aminium hexachloroantimonate (BAHA).