Recent Development in Self-Promoted N-Glycosylation

Session: 
S2.1 Oligosaccharide synthesis I
Code: 
FL2.1.6
Location (hall): 
Glucose
Start/end time: 
Monday, July 1, 2019 - 15:40 to 15:45
Christian
Pedersen

Christian M. Pedersen1, Michael M. Nielsen, Patrycja Mala, Eirikur Baldursson

1University of Copenhagen, Copenhagen O, Denmark

Anomeric sets of glycosyl trichloroacetimidates have been used as glycosyl donors together with carbamate protected sulfonamides for the synthesis of protected N-glycosides. The reaction is self-promoted and hence no additives or catalysts are added. 1,2-Trans axial trichloroacetimidates are stereo-specifically substituted, whereas the selectivity drops when having equatorial trichloroacetimidates. NMR studies suggest that the decrease in stereo-specificity is partly due to an anomerisation of the trichloroacetimidiate. Mechanistic studies based on NMR furthermore suggest a SN1 type reaction. The N-carbamate and the N-sulfonyl groups are furthermore shown to be orthogonally cleaved allowing further functionalization of the N-glycosides.

Sponsors

Sponsors