Nucleophile-Directed Stereocontrol Over Glycosylations Using Geminal-Difluorinated Nucleophiles
نویسندگان
چکیده
منابع مشابه
Nucleophile-Directed Stereocontrol Over Glycosylations Using Geminal-Difluorinated Nucleophiles.
The glycosylation reaction is the key transformation in oligosaccharide synthesis, but it is still difficult to control in many cases. Stereocontrol during cis-glycosidic linkage formation relies almost exclusively on tuning the glycosylating agent or the reaction conditions. Herein, we use nucleophile-directed stereocontrol to manipulate the stereoselectivity of glycosylation reactions. Placin...
متن کاملStereoselective glycosylations using oxathiane spiroketal glycosyl donors.
Novel oxathiane spiroketal donors have been synthesised and activated via an umpolung S-arylation strategy using 1,3,5-trimethoxybenzene and 1,3-dimethoxybenzene. The comparative reactivity of the resulting 2,4,6-trimethoxyphenyl (TMP)- and 2,4-dimethoxyphenyl (DMP)-oxathiane spiroketal sulfonium ions is discussed, and their α-stereoselectivity in glycosylation reactions is compared to the anal...
متن کاملDual stereocontrol over the Henry reaction using a light- and heat-triggered organocatalyst.
Here we present a novel dynamic organocatalyst, based on a first-generation molecular motor core, able to control the stereochemical outcome of the Henry reaction using both light and heat as external stimuli.
متن کامل1,3-Dibromo-5,5-dimethylhydantoin as promoter for glycosylations using thioglycosides
1,3-Dibromo-5,5-dimethylhydantoin (DBDMH), an inexpensive, non-toxic and stable reagent, is a competent activator of thioglycosides for glycosidic bond formation. Excellent yields were obtained when triflic acid (TfOH) or trimethylsilyl trifluoromethanesulfonate (TMSOTf) were employed as co-promoters in solution or automated glycan assembly on solid phase.
متن کاملNeighboring-group participation by C-2 ether functions in glycosylations directed by nitrile solvents.
Ether-protecting functions at C-2 hydroxy groups have been found to play participating roles in glycosylations when the reactions are conducted in nitrile solvent mixtures. The participation mechanism is based on intramolecular interaction between the lone electron pair of the oxygen atom of the C-2 ether function and the nitrile molecule when they are positioned in a cis configuration. A 1,2-c...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Angewandte Chemie International Edition
سال: 2016
ISSN: 1433-7851
DOI: 10.1002/anie.201606774