“On water” catalytic enantioselective sulfenylation of deconjugated butyrolactams

2017 ◽  
Vol 15 (33) ◽  
pp. 6921-6925 ◽  
Author(s):  
Soumya Jyoti Singha Roy ◽  
Santanu Mukherjee
Keyword(s):  
Reaction Medium ◽  
Catalyst System ◽  
Cinchona Alkaloids

The first catalytic enantioselective α-sulfenylation of deconjugated butyrolactams has been developed using dimeric cinchona alkaloids as catalysts in water-enriched reaction medium. The applicability of the same catalyst system for enantioselective α-selenylation and formal vinylogous γ-hydroxylation of deconjugated butyrolactam has also been described.

ARGET ATRP of acrylonitrile with ionic liquid as reaction medium and FeBr3/isophthalic acid as catalyst system

2011 ◽  
Vol 122 (5) ◽  
pp. 3298-3302 ◽  
Author(s):  
Hou Chen ◽  
Chunhua Wang ◽  
Delong Liu ◽  
Min Wang ◽  
Chunnuan Ji
Keyword(s):  
Ionic Liquid ◽  
Reaction Medium ◽  
Catalyst System ◽  
Isophthalic Acid ◽  
Arget Atrp

scholarly journals Manufacturing and Processing of Carbon Nanotubes for H2 Storage

2021 ◽  
Vol 22 (2) ◽  
pp. 209-216
Author(s):  
R. Namitha ◽  
Devi Radhika ◽  
Karthik Kannan ◽  
G. Krishnamurthy
Keyword(s):  
Carbon Nanotubes ◽  
Heating Temperature ◽  
Reaction Medium ◽  
Product Yield ◽  
Catalyst System ◽  
High Yield ◽  
Catalyst Precursor ◽  
Experimental Conditions ◽  
X Ray ◽  
Iron Nickel

In pursuit of manufacturing of carbon nanotubes (CNTs) in good yield at lower temperatures, a mixture of d-block elements such as Iron, Nickel, and Cobalt was expected to be advantageous because of the high yield and low temperature (at 220 - 250° C) synthesis. The physical state and aggregation of these catalyst particles in the reaction medium have been found to play an interesting role in obtaining CNTs at better yield. Carbon nanotubes have been successfully produced by an uncomplicated two-step solvothermal method between sodium and dichlorobenzene via Ni/Fe/Co as catalyst precursor.  The dependence of yield of CNTs on the catalyst system was determined via different ratios of catalysts and at various other experimental conditions such as different heating temperatures, different durations of heating. The X-ray powder diffraction study has indicated the graphite kind of the products. Microscopic characterizations (SEM and TEM) implied us the diameters of carbon nanotubes are 10-14 nm. Raman spectroscopy shows the presence of graphitized carbon in carbon nanotubes. Significant influence by the heating temperature and heating duration has been observed on the product yield.

Catalytic Oxidation of Phosphine by Ionic Liquid-Aqueous Biophasic

2013 ◽  
Vol 726-731 ◽  
pp. 2124-2129
Author(s):  
Yu Bing Xie ◽  
Guang Fei Qu ◽  
Ping Ning ◽  
Jiang Na Li ◽  
Yu Huan Liu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Reaction System ◽  
Reaction Medium ◽  
Catalyst System ◽  
Molar Ratio ◽  
Reaction Products ◽  
Mixed Gas ◽  
Amount Of Substance ◽  
Purification Efficiency ◽  
Ft Ir

hydrophobicity ionic liquid [bmiPF6 mix with PdCl2 is used as catalyst and reaction medium to form biophasic liquid reaction system to catalyst mixed gas of PH3. FT-IR is used for the conformational analysis of [bmi PF6 monomer and Waters 431 chromatograph for the products of purified reaction. The relationship between temperature, oxygen concentration, the amount of substance of PdCl2 and PH3 purification efficiency have been investigated. The results show that purification efficiency remains above 99% in 300min. There is no obvious increase of purification efficiency with O2 content increased. The optimum conditions of catalyst system are: [bmiPF6: PdCl2=1:0.056 (molar ratio), temperature of 70°C between 30~70°C. The reaction products contains PO43- in the aqueous phase by instrumental analysis.

Cyclopentyl methyl ether–NH4X: a novel solvent/catalyst system for low impact acetalization reactions

2015 ◽  
Vol 17 (6) ◽  
pp. 3281-3284 ◽  
Author(s):  
Ugo Azzena ◽  
Massimo Carraro ◽  
Ashenafi Damtew Mamuye ◽  
Irene Murgia ◽  
Luisa Pisano ◽  
...  
Keyword(s):  
Methyl Ether ◽  
Reaction Medium ◽  
Environmentally Friendly ◽  
Catalyst System ◽  
Ammonium Salts

Cyclopentyl methyl ether and ammonium salts provide an environmentally friendly reaction medium for the synthesis of acetals.

High-voltage cytochemistry for three-dimensional observation of nuclei and calculation of total numbers of nuclear pores in retinal Mueller glia

1990 ◽  
Vol 48 (3) ◽  
pp. 956-957
Author(s):  
H. Ishigooka ◽  
S. Ueno ◽  
L.M. Hjelmeland ◽  
M.B. Landers ◽  
K. Ogawa
Keyword(s):  
Nuclear Envelope ◽  
High Voltage ◽  
Three Dimensional ◽  
Reaction Medium ◽  
Nuclear Pores ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
G6pase Activity ◽  
Mueller Glia

Introduction: We have demonstrated that Glucose-6-phosphatase (G6Pase) activity is localized to the endoplasmic reticulum and nuclear envelope of Mueller glia in the normal and pathological guinea pig retina. Using a combination of this cytochemical technique and high voltage electron microscopy, the distribution of nuclear pores could be clearly observed on the nuclear envelope of Mueller glia because of their anatomical lack of reaction products. This technique was developed to study the three-dimensional structure of nuclei and to calculate total numbers of nuclear pores utilizing a computer graphic analysis system in the normal and pathological retina.Materials and methods: Normal and photocoagulated retina of pigmented adult guinea pigs were perfused with a cold mixture of 0.25% glutaraldehyde and 2% paraformaldehyde in 0.1M cacodylate buffer, and the enucleated globes were hemisected and immersed in the same fixative for 30 min. After sectioning and incubation in the reaction medium for the detection of G6Pase activity by the method of Wachstein-Meisel, the sections were postfixed, dehydrated and embedded in Spurr’s epoxy resin. Serial thick sections (1.0um) were prepared for the observation by a Hitachi high voltage electron microscope (H 1250-M) with an accelerating voltage of 1000 Kv. and pictures were analyzed and three-dimensionally reconstructed by TRI (RATOC Co., Ltd.).

Reaction of Acetaldehyde with Human Platelets

1992 ◽  
Vol 67 (01) ◽  
pp. 126-130 ◽  
Author(s):  
Olivier Spertini ◽  
Jacques Hauert ◽  
Fedor Bachmann
Keyword(s):  
Platelet Aggregation ◽  
Inhibitory Action ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Shape Change ◽  
Reaction Medium ◽  
Human Platelets ◽  
Membrane Glycoproteins ◽  
Neutral Ph

SummaryPlatelet function defects observed in chronic alcoholics are not wholly explained by the inhibitory action of ethanol on platelet aggregation; they are not completely reproduced either in vivo by short-term ethanol perfusion into volunteers or in vitro by the addition of ethanol to platelet-rich plasma. As acetaldehyde (AcH) binds to many proteins and impairs cellular activities, we investigated the effect of this early degradation product of ethanol on platelets. AcH formed adducts with human platelets at neutral pH at 37° C which were stable to extensive washing, trichloracetic acid hydrolysis and heating at 100° C, and were not reduced by sodium borohydride. The amount of platelet adducts formed was a function of the incubation time and of the concentration of AcH in the reaction medium. At low AcH concentrations (<0.2 mM), platelet bound AcH was directly proportional to the concentration of AcH in the reaction medium. At higher concentrations (≥0.2 mM), AcH uptake by platelets tended to reach a plateau. The amount of adducts was also proportional to the number of exposures of platelets to pulses of 20 pM AcH.AcH adducts formation severely impaired platelet aggregation and shape change induced by ADP, collagen and thrombin. A positive correlation was established between platelet-bound AcH and inhibition of aggregation.SDS-PAGE analysis of AcH adducts at neutral pH demonstrated the binding of [14C]acetaldehyde to many platelet proteins. AcH adduct formation with membrane glycoproteins, cytoskeleton and enzymes might interfere with several steps of platelet activation and impair platelet aggregation.This in vitro study shows that AcH has a major inhibitory action on platelet aggregation and may account for the prolonged ex vivo inhibition of aggregation observed in chronic alcoholics even in the absence of alcoholemia.

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