Carbohydrate protein interactions. Syntheses of agglutination inhibitors of wheat germ agglutinin by phase transfer catalysis

1991 ◽  
Vol 69 (5) ◽  
pp. 817-821 ◽  
Author(s):  
René Roy ◽  
François D. Tropper
Keyword(s):  
Protein Interactions ◽  
Wheat Germ ◽  
Room Temperature ◽  
Functional Group ◽  
Phase Transfer Catalysis ◽  
Methylene Chloride ◽  
Phase Transfer ◽  
Hydrogen Sulfate ◽  
Reaction Conditions ◽  
Tetrabutylammonium Hydrogen Sulfate

Starting from chloride 1, a series of para-substituted aryl 2-acetamido-2-deoxy-β-D-glucopyranosides were prepared using phase transfer catalysis conditions with tetrabutylammonium hydrogen sulfate in 1 M sodium hydroxide and methylene chloride at room temperature. Zemplén de-O-acetylation afforded the unprotected glycosides. Optimization of reaction conditions was evaluated. Several functional group manipulations were effected to widen the number and nature of the para-substituents. Key words: phase transfer catalysis, aryl 2-acetamido-2-deoxy-β-D-glucopyranosides.

Syntheses of glycosyl phosphates by phase transfer catalysis

1991 ◽  
Vol 69 (9) ◽  
pp. 1462-1467 ◽  
Author(s):  
René Roy ◽  
François D. Tropper ◽  
Chantal Grand-Maître
Keyword(s):  
Key Words ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Phase System ◽  
Hydrogen Sulfate ◽  
Two Phase ◽  
Glycosyl Phosphates ◽  
Glycosyl Phosphate ◽  
Tetrabutylammonium Hydrogen Sulfate ◽  
Complete Inversion

The peracetylated glycosyl bromides of D-glucose (1), D-galactose (2), and D-lactose (5) were treated with dibenzyl phosphate in a catalytic two-phase system using tetrabutylammonium hydrogen sulfate as catalyst. The reactions proceeded by complete inversion at the anomeric centers and afforded a new stereospecific entry into 1,2-trans-β-D-glycosyl phosphates of peracetylated D-glucose (3), D-galactose (4), and the disaccharide D-lactose (6) in 83, 73, and 83% yields respectively. Interestingly, the glycosyl chloride 7 furnished the oxazoline 9 rather than the expected glycosyl phosphate 8. Key words: phase transfer catalysis, glycosyl phosphates, phosphotriesters.

Rh(III)-Catalyzed Olefination and Alkylation of Arenes with Maleimides: A Tunable Strategy for C(sp2)–H Functionalization

Synthesis ◽  
2021 ◽  
Author(s):  
Hongji Li ◽  
Wenjie Zhang ◽  
Xueyan Liu ◽  
Zhenfeng Tian
Keyword(s):  
Room Temperature ◽  
Functional Group ◽  
Reaction Conditions ◽  
Bond Functionalization ◽  
Alkylation Process ◽  
Coupling Partner

AbstractWe herein report a new nitrogen-directed Rh(III)-catalyzed C(sp2)–H bond functionalization of N-nitrosoanilines and azoxybenzenes with maleimides as a coupling partner, in which the olefination/alkylation process can be finely controlled at room temperature by variation of the reaction conditions. This method shows excellent functional group tolerance, and presents a mild access to the resulting olefination/alkylation products in moderate to good yields.

Synthesis of Epoxidized Soybean Oil via Phase Transfer Catalysis

2013 ◽  
Vol 690-693 ◽  
pp. 1061-1064 ◽  
Author(s):  
Lu Jing ◽  
Guo Qin Liu ◽  
Xin Qi Liu ◽  
Xue De Wang
Keyword(s):  
Reaction Time ◽  
Soybean Oil ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Active Agent ◽  
Epoxidized Soybean Oil ◽  
Reaction Conditions ◽  
Epoxidation Reaction ◽  
Optimized Conditions ◽  
Epoxy Value

In the system of heteropoly acid [π-C5H5NC16H33]3[PO4(WO3)4], H2O2 (30 %, w/w), polyethylene glycol, 1,2-dichloroethane, soybean oil under went epoxidation reaction smoothly via reaction-controlled phase transfer catalysis. Effects of the amount of interfacial active agent, H2O2, catalyst and reaction time were investigated and the optimized reaction conditions were as follows: 10 g of soybean oil, 0.3 g of [π-C5H5NC16H33]3[PO4 (WO3)4],8 ml of H2O2 (30 %, w/w), 5.0 ml of PEG, 30 g of 1,2-dichloroethane, and the reaction temperature was 65 °C and reaction time was 3.5-4.0 h. Under these optimized conditions, an epoxy value of 6.30 % and a yield of 90 % were obtained. Hence, it is an environmental-friendly and effective way to synthesize epoxidized soybean oil.

A Rapid and High-yield Synthesis of Aryloxyacetyl Hydrazides under Microwave Irradiation and with Phase Transfer Catalysis

2005 ◽  
Vol 2005 (7) ◽  
pp. 432-433 ◽  
Author(s):  
Tai-Bao Wei ◽  
Hong Liu ◽  
Man-Lin Li ◽  
You-Ming Zhang
Keyword(s):  
Microwave Irradiation ◽  
Efficient Method ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
High Yield ◽  
Reaction Conditions

A series of aryloxyacetyl hydrazides 4a–l were synthesised under microwave irradiation and phase transfer catalysis conditions. By the optimisation of the reaction conditions, a rapid, high-yield and efficient method for the preparation of aryloxyacetyl hydrazide was given.

Synthesis of Biodiesel by Phase Transfer Catalysis

2013 ◽  
Vol 291-294 ◽  
pp. 355-358 ◽  
Author(s):  
Yan Qin Huang
Keyword(s):  
Reaction Time ◽  
Soybean Oil ◽  
Reaction Temperature ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Reaction Conditions ◽  
Optimum Reaction

Biodiesel was synthesized starting soybean oil and methanol using K2CO3 and phase-transfer catalysis TBAB. It was studied that the yield of biodiesel can be changed with reaction factors such as the kind and the amount of phase-transfer catalysis, the amount of K2CO3, reaction time, molar ratio between methanol and soybean oil, reaction temperature. The results show that the reaction conditions are as following: mass ratio of TBAB to soybean oil weight 0.6%, mass ratio of K2CO3 to soybean oil weight 1.5%, molar ratio between methanol and soybean oil 6∶1, reaction time 20 min, reaction temperature 40 °C. The yield of biodiesel reached 95% under the optimum reaction conditions.

Structural and Quantitative Analysis of Surface Modified Poly(vinylidene Fluoride) Films Using ATR FT-IR Spectroscopy

1987 ◽  
Vol 41 (5) ◽  
pp. 843-847 ◽  
Author(s):  
K. J. Kuhn ◽  
B. Hahn ◽  
V. Percec ◽  
M. W. Urban
Keyword(s):  
Quantitative Analysis ◽  
Vinylidene Fluoride ◽  
Phase Transfer ◽  
Hydrogen Sulfate ◽  
Poly Vinylidene Fluoride ◽  
Ft Ir ◽  
Surface Modified ◽  
And Behavior ◽  
Tetrabutylammonium Hydrogen Sulfate ◽  
Ft Ir Spectroscopy

The reaction of PVF2 films in aqueous NaOH with the use of tetrabutylammonium hydrogen sulfate as phase transfer catalyst results in surface dehydrofluorination. Subsequent examination of the PVF2 surface using ATR FT-IR affords evidence as to the structure of dehydrofluorinated PVF2. It is found that the infrared bands at 1402, 1225, 1194, and 882 cm−1 are sensitive to the surface treatment. The origin and behavior of these bands are discussed. It is observed that upon dehydrofluorination the FT-IR spectra of the PVF2 surface exhibit two infrared bands at 1613 cm−1 and 1717 cm−1 which arise from the formation of carbon-carbon double bonds. The band at 1613 cm−1 is due to conjugated -(-CH=CF-)- units, whereas the 1717 cm−1 band is assigned to the -(-CF=CF-)- units which arise from resonance at structural head-to-head and tail-to-tail defects.

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