139903-49-4Relevant academic research and scientific papers
Catalytic and Photochemical Strategies to Stabilized Radicals Based on Anomeric Nucleophiles
Chen, Zhenhao,Hong, Xin,Rui, Jinyan,Walczak, Maciej A.,Zhang, Shuo-Qing,Zhu, Feng
supporting information, p. 11102 - 11113 (2020/07/13)
Carbohydrates, one of the three primary macromolecules of living organisms, play significant roles in various biological processes such as intercellular communication, cell recognition, and immune activity. While the majority of established methods for the installation of carbohydrates through the anomeric carbon rely on nucleophilic displacement, anomeric radicals represent an attractive alternative because of their functional group compatibility and high anomeric selectivities. Herein, we demonstrate that anomeric nucleophiles such as C1 stannanes can be converted into anomeric radicals by merging Cu(I) catalysis with blue light irradiation to achieve highly stereoselective C(sp3)-S cross-coupling reactions. Mechanistic studies and DFT calculations revealed that the C-S bond-forming step occurs via the transfer of the anomeric radical directly to a sulfur electrophile bound to Cu(II) species. This pathway complements a radical chain observed for photochemical metal-free conditions where a disulfide initiator can be activated by a Lewis base additive. Both strategies utilize anomeric nucleophiles as efficient radical donors and achieve a switch from an ionic to a radical pathway. Taken together, the stability of glycosyl nucleophiles, a broad substrate scope, and high anomeric selectivities observed for the thermal and photochemical protocols make this novel C-S cross coupling a practical tool for late-stage glycodiversification of bioactive natural products and drug candidates.
Stereoretentive Reactions at the Anomeric Position: Synthesis of Selenoglycosides
Zhu, Feng,O'Neill, Sloane,Rodriguez, Jacob,Walczak, Maciej A.
supporting information, p. 7091 - 7095 (2018/05/29)
Reported is the stereospecific cross-coupling of anomeric stannanes with symmetrical diselenides, resulting in the synthesis of selenoglycosides with exclusive anomeric control. The reaction proceeds without the need for directing groups and is compatible
Useful approach to the synthesis of aryl thio- and selenoglycosides in the presence of rongalite
Venkateswarlu, Cheerladinne,Gautam, Vibha,Chandrasekaran, Srinivasan
, p. 48 - 53 (2014/08/18)
A simple, mild, and cost effective methodology has been developed for the synthesis of aryl thio-and selenoglycosides from glycosyl halides and diaryl dichalcogenides. Diaryl dichalcogenides undergo reductive cleavage in the presence of rongalite (HOCH2SO2Na) to generate a chalcogenide anion in situ followed by reaction with glycosyl halides to furnish the corresponding aryl thio- and selenoglycosides in excellent yields. Using this protocol, synthesis of 4-methyl-7-thioumbelliferyl-β-d-cellobioside (MUS-CB), a fluorescent non-hydrolyzable substrate analogue for cellulases has been achieved.
Photoinitiated glycosylation at 350 nm
Cumpstey, Ian,Crich, David
experimental part, p. 469 - 485 (2012/06/15)
A method for photochemical activation of glycosyl donors is presented. Selenoglycosides were activated by single-electron transfer using a photooxidant, N-methylquinolinium hexafluorophosphate, as photosensitizer and a toluene cosolvent as cosensitizer under irradiation at 350 nm. In this way we were able to synthesize glycosides including (1→6)-linked disaccharides. Benzyl ethers and benzoate esters were compatible with these conditions, allowing potentially synthetically useful transformations. The major by-products were due to hydrolysis; the reactions required the presence of oxygen and were run in air.
Selective activation of glycosyl donors utilising electrochemical techniques: A study of the thermodynamic oxidation potentials of a range of chalcoglycosides
France, Robert R.,Rees, Neil V.,Wadhawan, Jay D.,Fairbanks, Antony J.,Compton, Richard G.
, p. 2188 - 2194 (2007/10/03)
A series of six chalcoglycosides (phenyl-2,3,4,6-tetra-0-benzoyl-1-seleno-β-D-glucopyranoside, phenyl-2,3,4,6-tetraO-benzyl-1-seleno-β-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-thio-β-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzoyl-1-thio-β-D-glucop
Total synthesis of the Glc3Man N-glycan tetrasaccharide
Ennis,Cumpstey,Fairbanks,Butters,Mackeen,Wormald
, p. 9403 - 9411 (2007/10/03)
The total synthesis of the tetrasaccharide Glcα(1→2)Glcα(1→3)Glcα(1→3)ManαOMe, which corresponds to the terminal tetrasaccharide portion of the glucose terminated arm of the N-glycan tetradecasaccharide, was achieved by the use of differentially protected selenoglycosides and thioglycosides as glycosyl donors, all of which possessed non-participating protection of the 2-hydroxyl group. Favourable anomeric stereoselectivity was achieved for the glycosylation reactions by the use of ether as solvent, or co-solvent. Global deprotection by catalytic hydrogenation with palladium acetate in a mixture of ethanol and acetic acid yielded the target tetrasaccharide.
Novel Glycosidation Methodology. The Use of Phenyl Selenoglycosides as Glycosyl Donors and Acceptors in Oligosaccharide Synthesis
Mehta, Seema,Pinto, B. Mario
, p. 3269 - 3276 (2007/10/02)
The use of phenyl selenoglycosides as glycosyl donors and acceptors in glycosidation reactions is described.The versatility of these novel compounds is illustrated by the selective activation of both "disarmed" and "armed" phenyl selenoglycoside donors ov
Iodonium Ion-Mediated Glycosidations of Phenyl Selenoglycosides
Zuurmond, H. M.,Klein, P. A. M. van der,Meer, P. H. van der,Marel, G. A. van der,Boom, J. H. van
, p. 365 - 366 (2007/10/02)
Fully benzylated or benzoylated phenyl selenoglycosides can be activated by the promoters iodonium di-sym-collidine perchlorate (IDCP) or N-iodosuccinimide and catalytic triflic acid (NIS/TfOH cat.).The potential of the iodonium ion-mediated glycosidation
