Stereoselective C-glycosidations with achiral and enantioenriched allenylsilanes.
Allenylsilanes are used as carbon nucleophiles in highly stereoselective Lewis acid-promoted C-glycosidations, resulting in the introduction of an internal alkyne with an adjacent stereocenter. Both achiral and chiral allenylsilanes form the desired products with high diastereoselectivity, where the nucleophile adds exclusively to the α-face of the intermediate oxonium ion. Reactions with glucal and galactal afford dihydropyran products, while reactions with a ribose derivative yield dihydrofuran products.
Brawn
Ryan A
RA
Department of Chemistry and Center for Chemical Methodology and Library Development, Metcalf Center for Science and Engineering, 590 Commonwealth Avenue, Boston University, Boston, Massachusetts 02215, USA.
Panek
James S
JS
D000466:Alkadienes / Q000737:chemistry*; D006031:Glycosylation; D015394:Molecular Structure; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism
D000466:Alkadienes; D012821:Silanes; C025947:propadiene