2-Nitro-thioglycosides: α- and β-selective generation and their potential as β-selective glycosyl donors.
Michael-type addition of thiolates to 2-nitro-D-glucal or to 2-nitro-D-galactal derivatives readily provides 2-deoxy-2-nitro-1-thioglycosides. Kinetic and thermodynamic reaction control permitted formation of either the α- or preferentially the β-anomers, respectively. Addition of achiral and chiral thiourea derivatives to the reaction mixture increased the reaction rate; the outcome is substrate-controlled. The 2-deoxy-2-nitro-1-thioglycosides are excellent glycosyl donors under arylsulfenyl chloride/silver triflate (ArSCl/AgOTf) activation, and they provide, anchimerically assisted by the nitro group, mostly β-glycosides.
Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
Peng
P
Peng
Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
Yiqun
Y
Geng
Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
Inigo
I
Göttker-Schnetmann
Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
Richard R
RR
Schmidt
D020650:Combinatorial Chemistry Techniques; D006031:Glycosylation; D007700:Kinetics; D008698:Mesylates / Q000737:chemistry; D015394:Molecular Structure; D009574:Nitro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013816:Thermodynamics; D013865:Thioglycosides / Q000138:chemical synthesis* / Q000737:chemistry; D013890:Thiourea / Q000737:chemistry
D008698:Mesylates; D009574:Nitro Compounds; D013865:Thioglycosides; D013890:Thiourea; C012077:trifluoromethanesulfonic acid