183368-32-3Relevant academic research and scientific papers
Stereoretentive C(sp3)-S Cross-Coupling
Zhu, Feng,Miller, Eric,Zhang, Shuo-Qing,Yi, Duk,O'Neill, Sloane,Hong, Xin,Walczak, Maciej A.
supporting information, p. 18140 - 18150 (2019/01/04)
We report a stereoretentive cross-coupling reaction of configurationally stable nucleophiles with disulfide and N-sulfenylsuccinimide donors promoted by Cu(I). We demonstrate the utility of this method in the synthesis of thioglycosides derived from simple alkyl and aryl thiols, thioglycosides, and in the glycodiversification of cysteine residues in peptides. These reactions operate well with carbohydrate substrates containing common protective groups and reagents with free hydroxyl and secondary amide functionalities under standardized conditions. Competition experiments in combination with computational DFT studies established that the putative anomeric intermediate is an organocopper species that is configurationally stable and resistant to epimerization due to its short lifetime. The subsequent reductive elimination from the Cu(III) intermediate is rapid and stereoretentive. Taken together, the glycosyl cross-coupling is ideally suited for late stage glycodiversification and bioconjugation under highly controlled installation of the aliphatic carbon-sulfur bonds.
Reversal of anomeric selectivity with O-glycosyl trichloroacetimidates as glycosyl donors and thiols as acceptors under acid/base catalysis
Kumar, Amit,Schmidt, Richard R.
experimental part, p. 2715 - 2719 (2012/06/30)
Boron trifluoride or trimethylsilyl trifluoromethanesulfonate catalysed the generation of thioglycosides from O-glucopyranosyl or O-galactopyranosyl trichloroacetimidates and thiols giving mainly or exclusively α-thioglycosides. However, the same reaction
A practical synthesis of α-D-Manp-(1→3)-α-D-Manp- (1→2)-[α-D-Glcp-(1→3)]-α-D-Manp-(1→2) -α-D-Manp-(1→2)-α-D-Manp, an O-specific heterohexasaccharide fragment of Citrobacter braakii O7a, 3b, 1c
Chen, Langqiu,Kong, Fanzuo
, p. 2169 - 2175 (2007/10/03)
An O-specific heterohexasaccharide fragment of Citrobacter braakii O7a, 3b, 1c, α-D-Manp-(1→3)-α-D-Manp-(1→2)-[α-D-Glcp- (1→3)]-α-D-Manp-(1→2)-α-D-Manp-(1→2)-α-D-Manp was synthesized as its methyl glycoside. Acetylation of allyl 4,6-O-benzylidene-α-D-mannopyranoside, followed by debenzylidenization and benzoylation gave allyl 2,3-di-O-acetyl-4,6-di-O-benzoyl-α-D- mannopyranoside (3), and subsequent deacetylation of 3 with CH 3COCl-MeOH gave the monosaccharide acceptor 4. Condensation of isopropyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-glucopyranoside (6) with 4 selectively afforded the α-(1→3)-linked disaccharide 7. Condensation of 7 with the (1→3)-linked disaccharide donor 9, followed by deallylation and trichloroacetimidation, afforded the tetrasaccharide donor 12. Coupling of 12 with disaccharide acceptor 13, followed by debenzylation and deacylation, furnished the target heterohexasaccharide 16.
A new route to exo-glycals using the Ramberg-Baecklund rearrangement
Griffin, Frank K.,Paterson, Duncan E.,Murphy, Paul V.,Taylor, Richard J. K.
, p. 1305 - 1322 (2007/10/03)
A new route to exo-glycals 4 is described in which glycosyl sulfones 3 are subjected to the Meyers variant of the Ramberg-Baecklund rearrangement. The conversion of sulfones derived from glucose, galactose, mannose, cellobiose, and ribose into di-, tri-, and tetra-substituted alkenes is reported. Preliminary mechanistic studies of this process are also described. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
