78890-68-3Relevant articles and documents
A protecting group-free approach for synthesizingC-glycosides through glycosyl dithiocarbamates
Li, Gefei,Noguchi, Masato,Arisaka, Genki,Tanaka, Yuuki,Shoda, Shin-Ichiro
supporting information, p. 3134 - 3138 (2021/04/21)
The first protection/deprotection-free process for radicalC-glycosylation has been achieved through one-step preparable glycosyl dithiocarbamates (GDTCs). The Giese-type reaction and radical allylation of unprotected GDTCs were successfully performed to obtain the corresponding α-C-glycosides stereoselectively under mild reaction conditions.
Additive-controlled synthesis of 1- and 2-dexoysugars from thioglycosides
Gao, Chen-Fei,Wu, Biao,Wu, Xia,Xiong, De-Cai,Ye, Xin-Shan
, (2021/12/29)
Two photoreactions for the synthesis of 1- and 2-deoxysugars from thioglycosides were developed. In the presence of Hantzsch ester as an additive, a wide range of 1-deoxysugars were synthesized in moderate to excellent yields under irradiation with UV light without an exogenous photosensitizer. On the other hand, the utilization of 2,4,6-tri-tert-butylpyrimidine (TTBP) as the additive furnished a variety of 2-deoxysugars as the main products from their corresponding thioglycosides. The reported methodology has a broad substrate scope and high functional group tolerance and is scalable to gram-scale reaction.
Synthesis of Deoxyglycosides by Desulfurization under UV Light
Ge, Jian-Tao,Li, Ying-Ying,Tian, Jun,Liao, Rong-Zhen,Dong, Hai
, p. 7008 - 7014 (2017/07/15)
This study was performed to develop a highly efficient method whereby desulfurization could be completed in 0.5 h under ultraviolet light, at room temperature, and in the presence of trialkylphosphine. Using this method, deoxyglycosides could be produced from sulfur-containing glycosides in almost quantitative yields. The much higher reactivity of desulfurization with triethylphosphine versus that with triethylphosphite is also discussed.
Synthesis of - C -glycosides by samarium diiodide mediated coupling of glycosyl pyridyl sulfones with alkenes
Li, Gen,Xiong, De-Cai,Ye, Xin-Shan
scheme or table, p. 2410 - 2414 (2011/11/04)
A mild method for the synthesis of -C-glycosides by the samarium diiodide mediated coupling reactions of glycosyl 2-pyridyl sulfones with different ,-unsaturated carbonyl compounds has been developed. This method allows the use of less amount of substrates. Georg Thieme Verlag Stuttgart - New York.
Synthesis of aromatic C-xylosides by position inversion of glucose
Malmberg, Jesper,Mani, Katrin,Saewen, Elin,Wiren, Anders,Ellervik, Ulf
, p. 6659 - 6665 (2007/10/03)
Two formally C-xylosylated analogs to 2-naphthyl β-d-xylopyranoside, which is known to initiate priming of glucosaminoglycan chains, were synthesized by a position inversion of glucose (i.e., position 1 becomes position 5). The d-C-xyloside showed priming, while the l-C-xyloside did not initiate priming.
Triisobutylaluminium and dusobutylaluminium hydride as molecular scalpels: The regioselective stripping of perbenzylated sugars and cyclodextrins
Lecourt, Thomas,Herault, Alexandre,Pearce, Alan J.,Sollogoub, Matthieu,Sinay, Pierre
, p. 2960 - 2971 (2007/10/03)
To explain the remarkable regioselective de-O-benzylating properties of diisobutylaluminium hydride (DIBAL-H) and triisobutylaluminium (TIBAL) towards polybenzylated sugars or cyclodextrins, we propose a plausible mechanistic rationale critically involving the kinetic formation of a product-generating 2:1 Al-benzylated sugar complex. For the reaction to occur, one pair of adjacent oxygen atoms should first be able to form a chelation complex with the first equivalent of aluminium reagent, either a highly fluxional complex with tetracoordinate aluminium species or a pentacoordinate one. The second equivalent then induces the regioselectivity of the de-O-alkylation by coordinating preferentially to one of the oxygen atoms of the selected pair.
A new strategy for the stereoselective syntheses of C-glycosyl compounds of β-pentapyranoses
Guo, Zhong-Wu,Hui, Yong-Zheng
, p. 2067 - 2073 (2007/10/03)
The C-glycosyl compounds of β-L-xylopyranose and β-D-arabinopyranose were conveniently prepared by reduction of methyl α-D-glucopyranoside and methyl α-D-mannopyranoside with triethylsilane in the presence of trimethylsilyl trifluoromethanesulfonate, respectively.
Formation of heterocycles by the Mitsunobu reaction. Stereoselective ynthesis of (+)-α-skytanthine
Tsunoda,Ozaki,Shirakata,Tamaoka,Yamamoto,Ito
, p. 2463 - 2466 (2007/10/03)
Cyanomethylenetributylphosphorane was shown to mediate the dehydrocyclization of diols and amino alcohols to give the corresponding 6-membered O- and N-heterocycles in 90% or better yields. Using the reaction as a key step, (+)-α-skytanthine, a unique mono terpene alkaloid, was synthesized stereoselectively.
SmI2-promoted chemistry at the anomeric center of carbohydrates. Reductive formation and reaction of glycosyl samarium (III) reagents
Pouilly, P. de,Chenede, A.,Mallet, J.-M.,Sinay, P.
, p. 256 - 265 (2007/10/02)
Reaction of 3,4,6-tri-O-benzyl-2-deoxy-α-D-arabino-hexopyranosyl chloride at room temperature with the efficient single electron transfer system of SmI2-THF-HMPA, in the presence of cyclopentanone (Barbier conditions) gave selectively the corresponding α-C-glycoside in 70percent yield.It is postulated that the reactive transient intermediate is a chiral anomeric organosamarium (III) species.Lower yields were obtained in the presence of aldehydes, such as n-butanal or isobutanal.It is also demonstrated that glycosyl phenyl sulfones undergo reductive samariation. 2,3,4,6-Tetra-O-benzyl-β-D-glucopyranosyl phenyl sulfone reacted with cyclopentanone, in the presence of SmI2-THF-HMPA, to give the corresponding β-C-glycoside selectively in 25percent yield, together with the elimination product (40percent).When the protecting group at C-2 was an acetate, a very fast β-elimination of the organosamarium intermediate occurred to give a practically quantitative yield of a substituted glycal.This work constitutes the first application of samarium(II) iodide to the reductive metallation of the anomeric center of carbohydrates.Key words: samarium diiodide / sulfones / carbohydrates / glycals / C-glycosides
Reductive elimination of glycosyl phenyl sulfones by SmI2-HMPA: A convenient synthesis of substituted pyranoid glycals
De Pouilly, Pierre,Chenede, Alain,Mallet, Jean-Maurice,Sinay, Pierre
, p. 8065 - 8068 (2007/10/02)
A series of substituted glycosyl phenyl sulfones was converted into glycals after reductive samariation with SmI2 in the presence of hexamethylphosphoric triamide, followed by elimination of the substituent at C-2. Practically quantitative yields were obtained when the leaving group was an acetate, as illustrated here with seven substrates.
