40246-30-8Relevant academic research and scientific papers
Erratum to “Ionic liquids as phase transfer catalysts: Enhancing the biphasic extractive epoxidation reaction for the selective synthesis of β-O-glycosides” (Tetrahedron Letters (2017) 58(38) (3739–3742) (S0040403917310316) (10.1016/j.tetlet.2017.08.033))
Santiago, Cintia C.,Lafuente, Leticia,Bravo, Rodolfo,Díaz, Gisela,Ponzinibbio, Agustín
, p. 3942 - 3942 (2017)
The publisher regrets that references 15, 16, 18 and 19 contained errors. The correct references are as follows: 15. 1-Dodecyl-3-methylimidazolium tetrafluoroborate. Anhydrous sodium tetrafluoroborate (15.30 g, 0.14 mol), 1-methylimidazole (11.5 ml, 0.14
Simple and mild stereoselective O-glycosidation using 1,2-anhydrosugars under neutral conditions
Somasundaram, Devaraj,Balasubramanain, Kalpattu K.,Shanmugasundaram, Bhagavathy
supporting information, p. 764 - 767 (2019/02/16)
The ring opening of α-D-1,2-anhydrohexapyranoses with phenols proceeded smoothly in ethyl acetate (neutral conditions) in the absence of metal ion catalysts or additives to stereoselectively furnish 1,2-cis-α-aryl glycosides as the major product and 1,2-t
Arylboronic acid-mediated glycosylation of 1,2-dihydroxyglucoses
Izumi, Sanae,Kobayashi, Yusuke,Takemoto, Yoshiji
, p. 350 - 362 (2019/07/31)
- We explored direct dehydrative coupling of tetrahydro-2H-pyran-2,3-diol or a 1,2-dihydroxy sugar with various alcohols using a range of arylboronic acids. Among the catalysts, 2-borono-4-trifluoromethylbenzoic acid efficiently promoted acetalization of tetrahydro-2H-pyran-2,3-diol. Ferroceniumboronic acid showed the best catalytic activity for glycosylation of the 1,2-dihydroxy sugar. The major products were 1,2-cJi-a-D-glucopyranosides.
Ionic liquids as phase transfer catalysts: Enhancing the biphasic extractive epoxidation reaction for the selective synthesis of β-O-glycosides
Santiago, Cintia C.,Lafuente, Leticia,Bravo, Rodolfo,Díaz, Gisela,Ponzinibbio, Agustín
, p. 3739 - 3742 (2017/09/02)
Ionic liquids promoted the direct epoxidation of glycals acting as PTC. 1,2-anhydrosugars were prepared by the oxidation of glycals under biphasic conditions with dimethydioxirane generated in situ from oxone/acetone and amphiphilic IL's as catalysts. β-O
Co2(CO)6-propargyl cation mediates glycosylation reaction by using thioglycoside
Xia, Meng-jie,Yao, Wang,Meng, Xiang-bao,Lou, Qing-hua,Li, Zhong-jun
supporting information, p. 2389 - 2392 (2017/05/29)
We discovered that the cobalt-propargyl cation can mediate the glycosylation reaction by activating the thioglycoside donor. The glyco-oxacarbenium cation was formed by transferring the thio-aglycone to the cobalt-propargyl cation that was generated from the cobalt-propargylated acceptor in situ via the activating with Lewis acid. The reactivity of the donor (Armed or dis-armed) and the amount of the Lewis acid control the releasing rate of the cobalt-propargyl group.
Application of 2-substituted benzyl groups in stereoselective glycosylation
Buda, Szymon,Nawj, Miroslaw,Golbiowska, Patrycja,Dyduch, Karol,Michalak, Artur,Mlynarski, Jacek
, p. 770 - 780 (2015/03/03)
The use of 2-O-(2-nitrobenzyl) and 2-O-(2-cyanobenzyl) groups controls stereoselective formation of 1,2-trans-glycosidic linkages via the arming participation effect. The observed stereoselectivity likely arises from the intramolecular formation of cyclic intermediate between the electron-rich substituent and the donor oxacarbenium ion providing the expected facial selectivity for attack of the glycoside acceptor. The stereodirecting effect of the 2-nitro- and 2-cyanobenzyl groups attached at the remote position (C-3, C-4, and C-6) of the donor molecule have also been investigated. To prove the postulated mechanism based on the participation effect of 2-substituted benzyl groups in the glycosylation stereoselectivity we used DFT theoretical calculation methodology.
Application of the 2-nitrobenzyl group in glycosylation reactions: A valuable example of an arming participating group
Buda, Szymon,Golebiowska, Patrycja,Mlynarski, Jacek
, p. 3988 - 3991 (2013/07/19)
The application of the o-nitrobenzyl (oNBn) group is demonstrated. This practical methodology allows the stereocontrolled synthesis of glucosides with a 1,2-trans linkage. This new ether-type arming group can broadly extend the concept of the use of participating groups in glycosylation reactions. Easy protection and deprotection of the oNBn group further confirms its usefulness in synthesis. The application of o-nitrobenzyl (oNBn) ether as an arming participating group is demonstrated. This practical methodology allows the stereocontrolled synthesis of glucosides with a 1,2-trans linkage. Copyright
Epoxidation of glycals with oxone-acetone-tetrabutylammonium hydrogen sulfate: A convenient access to simple β-D-glycosides and to α-D-mannosamine and D-talosamine donors
Lafont, Dominique,D'Attoma, Joseph,Gomez, Rejane,Goekjian, Peter G.
, p. 1197 - 1204 (2011/10/19)
The addition of a phase transfer catalyst during the epoxidation of perbenzylated glycals with oxone- acetone under biphasic conditions allows their complete epoxidation. The epoxides were readily transformed into methyl 1,2-trans-β-D-glycosides or 1,2-trans-β-D-glycopyranosyl azides (D-gluco and-D-galacto configurations) bearing a free hydroxyl group at the 2-position. These glycosyl azides were converted to alkyl 1,2-trans-2-acetamido- 2-deoxy-α-D-pyranosides or alkyl 2-allyloxycarbonylamino-2- deoxy-α-D-pyranosides (D-manno and D-talo configurations) by a Staudinger reaction and a double inversion of configuration at C-1 and C-2.
Tandem epoxidation-alcoholysis or epoxidation-hydrolysis of glycals catalyzed by titanium(IV) isopropoxide or Venturello's phosphotungstate complex
Levecque, Pieter,Gammon, David W.,Kinfe, Henok Hadgu,Jacobs, Pierre,De Vos, Dirk,Sels, Bert
body text, p. 1557 - 1568 (2009/07/10)
Venturello's phosphotungstate complex and titanium(IV) isopropoxide [Ti(O-i-Pr)4] were successfully used as catalysts for the epoxidation-alcoholysis of glycals using hydrogen peroxide [H2O 2]. Reaction substrates included a range of variously protected glycals and different alcohols were used as solvents. Ti(O-i-Pr)4 was only effective in methanol as solvent, but gave methyl glycosides in high yields and high selectivities. The Venturello complex proved to be a very versatile and efficient catalyst. Apart from epoxidation-alcoholysis in alcoholic solvents it also showed activity in biphasic conditions to allow for glycosylation of long-chain alcohols and was very effective in the stereoselective dihydroxylation of benzylated glucal.
Direct epoxidation of d-glucal and d-galactal derivatives with in situ generated DMDO
Cheshev, Pavel,Marra, Alberto,Dondoni, Alessandro
, p. 2714 - 2716 (2007/10/03)
A multi-gram epoxidation of 3,4,6-tri-O-benzyl-d-glucal and d-galactal with dimethyldioxirane (DMDO) generated in situ from Oxone/acetone in a biphasic system (CH2Cl2-aqueous NaHCO3) resulted in the formation of
