C-Glycosylation of Oxygenated Naphthols with 3-Dimethylamino-2,3,6-trideoxy-L-arabino-hexopyranose and 3-Azido-2,3,6-trideoxy-D-arabino-hexopyranose

2003 ◽  
Vol 56 (8) ◽  
pp. 787 ◽  
Author(s):  
Margaret A. Brimble ◽  
Roger M. Davey ◽  
Malcolm D. McLeod ◽  
Maureen Murphy
Keyword(s):  
Lewis Acid ◽  
Boron Trifluoride ◽  
Electronic Effects ◽  
Effective Coupling ◽  
Boron Trifluoride Diethyl Etherate ◽  
Glycosyl Donor ◽  
Aryl Glycosides ◽  
Coupling Partner ◽  
Fine Tune ◽  
Glycosyl Donors

In connection with studies directed towards the synthesis of the pyranonaphthoquinone antibiotic medermycin, C-aryl glycosides were prepared by C-glycosylation of naphthols with glycosyl donors. Boron trifluoride diethyl etherate proved to be a suitable Lewis acid to promote the C-glycosylation, and use of the azido glycosyl donor proved more successful than using the dimethylamino glycosyl donor. 5-Hydroxy-1,4-dimethoxynaphthalene underwent facile C-glycosylation with two particular glycosyl donors, whereas 3-bromo-5-hydroxy-1,4-dimethoxynaphthalene was not an effective coupling partner with the same glycosyl donors. These studies indicate that subtle steric and electronic effects need to be considered in order to fine-tune C-glycosylations when using highly functionalized glycosyl donors.

scholarly journals Synthesis of N-pentofuranosyl oxazolines and amides though the selective transformations of D-sugar acetonides

2021 ◽  
Vol 65 (5) ◽  
pp. 558-567
Author(s):  
G. G. Sivets ◽  
A. V. Sivets
Keyword(s):  
Lewis Acid ◽  
Boron Trifluoride ◽  
Selective Hydrolysis ◽  
Boron Trifluoride Diethyl Etherate ◽  
Potassium Hydrogen ◽  
High Yields ◽  
Neutral Conditions ◽  
Hydrolysis Of ◽  
Hydrolysis Reactions

The method for synthesis of N-pentofuranosyl oxazolines was developed from the protected 1,2-O-acetonides of D-xylofuranose, -ribofuranose, and -arabinofuranose using boron trifluoride diethyl etherate, acetonitrile, and potassium hydrogen difluoride. A possible mechanism of the catalyzed reaction of acylated acetonides with acetonitrile in the presence of Lewis acid was considered in terms of the activation and cleavage of the 1,3-dioxalane part of the xylose derivative fol- lowed by the conversions of intermediates to α-isooxazoline. The hydrolysis reactions of N-α-glycosyl oxazolines were stud- ied in the acidic and neutral conditions. N-α-xylofuranosyl acetamide derivatives were prepared in high yields as a result of selective hydrolysis of protected α-xylofuranosyl isooxazolines in the neutral conditions.

Alkylation of Partially Protected Xylofuranoses and Tetritols with (2,2,3,3,4,4,5,5,6,6,7,7,7-Tridecafluoroheptyl)oxirane and the Stability of Protecting Acetal Groups Towards Lewis Acid-Type Catalyst

2001 ◽  
Vol 66 (11) ◽  
pp. 1665-1681 ◽  
Author(s):  
Karel Kefurt ◽  
Jitka Moravcová ◽  
Šárka Bambasová ◽  
Kateřina Buchalová ◽  
Barbora Vymětalíková ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Boron Trifluoride ◽  
Catalytic Amount ◽  
Boron Trifluoride Diethyl Etherate ◽  
Acid Type ◽  
The Stability

1,2-O-Isopropylidene-3-O-methyl-α-D-xylofuranose (2), 1,2-O-isopropylidene-α-D-xylofuranose (3), 2,4-O-ethylidene-D-erythritol (4) and 1,3-O-ethylidene-D-threitol (5) were alkylated with racemic (2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoroheptyl)oxirane (1) using boron trifluoride diethyl etherate as a catalyst. The desired mono- or disubstituted polyfluoroalkyl derivatives 6-11 were isolated only in low to medium yields. The fluoroalkylation was accompanied with disproportional distributions of the protecting acetal/ketal groups and polymerization of saccharides. Therefore the stability of 3, 4, 5, 5-O-acetyl-1,2-O-isopropylidene-α-D-xylofuranose (14) and 1,2-O-isopropylidene-α-D-glucofuranose (15) in the presence of a catalytic amount of boron trifluoride diethyl etherate was investigated in various solvents. A mechanism explaining the effect of the catalyst has been proposed.

Remote Electronic Effects by Ether Protecting Groups Fine-Tune Glycosyl Donor Reactivity

2016 ◽  
Vol 81 (12) ◽  
pp. 4988-5006 ◽  
Author(s):  
Mads Heuckendorff ◽  
Lulu Teressa Poulsen ◽  
Henrik H. Jensen
Keyword(s):  
Protecting Groups ◽  
Electronic Effects ◽  
Glycosyl Donor ◽  
Fine Tune

Electrosyntheses of Poly(selenophene-co-3-methylthiophene) with Improved Thermoelectric Property in Boron Trifluoride Diethyl Etherate

2014 ◽  
Vol 937 ◽  
pp. 17-22 ◽  
Author(s):  
Sheng Tao Wang ◽  
Bao Yang Lu ◽  
Jing Kun Xu ◽  
Wei Qiang Zhou
Keyword(s):  
Cyclic Voltammetry ◽  
Infrared Spectroscopy ◽  
Electrochemical Oxidation ◽  
Thermoelectric Property ◽  
Boron Trifluoride ◽  
Monomer Concentration ◽  
Thermoelectric Measurements ◽  
Boron Trifluoride Diethyl Etherate ◽  
Concentration Ratios

Novel poly (selenophene-co-3-methylthiophene) was successfully achieved by directly electrochemical oxidation of the monomer mixtures of selenophene and 3-methylthiophene (3MeT) in boron trifluoride diethyl etherate. The effect of monomer concentration ratios on the copolymerization were investigated by cyclic voltammetry. The structures of as-prepared copolymers were characterized by UV-vis and infrared spectroscopy. The conductivity and thermoelectric measurements revealed the incorporation of 3MeT into the polyselenophene (PSe) chain improved significantly the conductivity and thermoelectric property of PSe.

scholarly journals Functionalized BODIPY Derivatives as Potential Fluorescent Labels

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Raquel C. R. Gonçalves ◽  
Mariana B. Nogueira ◽  
Susana P. G. Costa ◽  
M. Manuela M. Raposo
Keyword(s):  
Boron Trifluoride ◽  
Spectroscopic Techniques ◽  
Fluorescent Labels ◽  
Absorption Bands ◽  
Boron Trifluoride Diethyl Etherate ◽  
Photophysical Study ◽  
Intense Absorption ◽  
Emission Studies

4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives 1 and 2 were obtained with 16% and 33% yield by a two-step reaction: condensation of a pyrrole with the corresponding aldehyde followed by oxidation with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in the presence of boron trifluoride diethyl etherate (BF3OEt2). The two compounds were characterized by the usual spectroscopic techniques and a detailed photophysical study was undertaken. The compounds exhibited intense absorption bands at 502 nm and 497 nm, respectively. Emission studies of the compounds 1 and 2 showed emission bands with maximum wavelength at 518 nm and 519 nm, respectively.

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