Anionic polymerization of acrylic thioester by using organic base

2020 ◽  
Vol 11 (6) ◽  
pp. 1145-1150 ◽  
Author(s):  
Masato Suzuki ◽  
Takumi Kaneko ◽  
Yuna Ishikawa ◽  
Shin-ichi Matsuoka
Keyword(s):  
Anionic Polymerization ◽  
Organic Base ◽  
Anionic Sites ◽  
Organic Bases

An acrylic thioester is polymerized with organic bases as the initiators via zwitterionic mechanisms involving propagation at the anionic sites.

Synthesis of Sterically Congested Carbamates of Carbohydrates through Organic Base Catalysis

Synthesis ◽  
2019 ◽  
Vol 51 (15) ◽  
pp. 2897-2908 ◽  
Author(s):  
Anji Chen ◽  
Dan Wang ◽  
Lalith P. Samankumara ◽  
Guijun Wang
Keyword(s):  
Hydroxy Group ◽  
Current Method ◽  
Building Blocks ◽  
Base Catalysis ◽  
Organic Base ◽  
Molecular Assemblies ◽  
Effective Catalyst ◽  
Organic Bases ◽  
Derivatives Of ◽  
General Method

4,6-O-Benzylidene acetal protected α-methoxy d-glucose and d-glucosamine are useful building blocks for the syntheses of carbohydrate derivatives and functional molecular assemblies. In this research, we have developed a general method for the preparation of C-3 carbamate derivatives of densely functionalized glucose and glucosamine with isocyanates using organic bases as catalysts. Without a suitable catalyst, the C-3 hydroxy group of the glucosamine derivative could not be converted into the corresponding carbamates when treated with isocyanates. Several organic bases were screened as the catalysts for the reactions, and we discovered that 5.0 mol% of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was an effective catalyst for the carbamoylation reaction. A library of both alkyl and aryl carbamate derivatives of the two sterically congested carbohydrates have been effectively synthesized using the current method.

scholarly journals TUBULAR SECRETION OF CREATINE, TRIMETHYLAMINE OXIDE, AND OTHER ORGANIC BASES BY THE AGLOMERULAR KIDNEY OF LOPHIUS AMERICANUS

1958 ◽  
Vol 42 (2) ◽  
pp. 319-327 ◽  
Author(s):  
Roy P. Forster ◽  
Fredrik Berglund ◽  
Barbara R. Rennick
Keyword(s):  
Plasma Concentration ◽  
Tubular Secretion ◽  
Tubular Reabsorption ◽  
Cyanine Dye ◽  
Transport Mechanisms ◽  
Organic Base ◽  
Organic Bases ◽  
Trimethylamine Oxide ◽  
Tetraethylammonium Ion ◽  
Concentration Ratios

Creatine and trimethylamine oxide (TMAO) are the chief nitrogenous constituents of normal Lophius urine, and both of these organic bases characteristically have high urine/plasma concentration ratios. Competition studies involving various organic bases indicate that creatine and TMAO are excreted independently by separate transport mechanisms. TMAO excretion is inhibited competitively by tetraethylammonium ion (TEA) and by cyanine dye No. 863—compounds previously shown to be transferred actively by an organic base-secreting mechanism of general occurrence among vertebrates. TEA does not inhibit competitively the active tubular reabsorption of TMAO in Squalus with doses which markedly depress its tubular excretion in Lophius. Glycine, which inhibits creatine reabsorption in the dog, does not interfere competitively with its secretion in Lophius.

Cimetidine and procainamide secretion by proximal tubules in vitro

1982 ◽  
Vol 242 (6) ◽  
pp. F672-F680 ◽  
Author(s):  
T. D. McKinney ◽  
K. V. Speeg
Keyword(s):  
Competitive Inhibition ◽  
Proximal Tubules ◽  
Renal Tubules ◽  
Co2 Absorption ◽  
Organic Base ◽  
Organic Bases ◽  
Straight Tubules ◽  
Tubule Lumen ◽  
High Concentrations

Previous studies have shown that organic bases, including some drugs, are secreted by renal proximal tubules. The present studies examined the transport of the organic bases cimetidine and procainamide by rabbit proximal straight tubules perfused in vitro. Both drugs were secreted into the tubule lumen. [3H]cimetidine secretion was reduced by quinidine, procainamide, and N-acetylprocainamide. Previous studies showed that cimetidine secretion was reduced by other organic bases. Hypothermia and ouabain inhibited [3H]procainamide secretion as was shown previously for cimetidine secretion. [3H]procainamide secretion was also reduced by quinidine, cimetidine, procainamide, and N-acetylprocainamide but not by probenecid. High concentrations of cimetidine (10(-3) M) had no effect on the rates of fluid or total CO2 absorption. When analyzed in terms of Michaelis-Menten kinetics, the effect of cimetidine on procainamide secretion and procainamide on cimetidine secretion was consistent with competitive inhibition. The results suggest that both cimetidine and procainamide are secreted into the lumen of proximal straight tubules predominately by an organic base transport mechanism. These studies raise the possibility that some of these drugs might compete for a common secretory mechanism in renal tubules and reduce the elimination of each other.

scholarly journals II. On the formation and some of the properties of cymidine, the organic base of the cymole series

1856 ◽  
Vol 146 ◽  
pp. 15-19
Keyword(s):  
Nitric Acid ◽  
Royal College ◽  
Carbonic Acid ◽  
Nitro Compounds ◽  
The Other ◽  
Organic Base ◽  
Substitution Product ◽  
Simultaneous Formation ◽  
Organic Bases ◽  
Made In

By submitting the nitro-compounds of the series of hydrocarbons, of which benzole is the lowest term, to Zinin’s well-known process, chemists have successively obtained the organic bases corresponding to these hydrocarbons. Aniline, toluidine, xylidine and cumidine have been prepared in this manner. Aniline was obtained by this process by Zinin* himself in 1845; toluidine by Muspratt and Hofmann†, in 1845; xylidine by Cahours‡, in 1850; and cumidine by Nicholson, in 1847§. Whilst the last-named chemist was engaged in the laboratory of the Royal College of Chemistry with the study of cumidine, the derivative of cumole, Dr. Noad, at the suggestion of Dr. Hofmann, pursued the same direction of research towards cymole, the only remaining hydrocarbon of this group, with a view of completing the series of the alkaloids||. In his experiments on the action of concentrated nitric acid on cymole, Dr. Noad found that this hydrocarbon differs somewhat from the other members of the series. Instead of furnishing the nitro-substitute, which is the link of connexion between the hydrocarbon and the alkaloid, cymole was found to undergo a partial oxidation, a portion of the carbon being eliminated in the form of carbonic acid with the simultaneous formation of several acids which belong to a group of bodies standing lower in the scale of organic compounds. The study of these very interesting acids, toluylic and nitrotoluylic, appears to have detached Dr. Noad’s attention from the formation of the substitution-product of cymole; and when he again returned to this inquiry he soon quitted it, in order to pursue still further a research in which he had already been successful¶. At the suggestion, and under the direction of Dr. Hofmann, the following investigation has been made, in the hope of filling up a gap still existing in the series of bases, and the desired alkaloid has been obtained; thus completing the inquiry which was commenced in the Royal College of Chemistry seven years ago.

scholarly journals Efficient CO2 capture by tertiary amine-functionalized ionic liquids through Li+-stabilized zwitterionic adduct formation

2014 ◽  
Vol 10 ◽  
pp. 1959-1966 ◽  
Author(s):  
Zhen-Zhen Yang ◽  
Liang-Nian He
Keyword(s):  
Ionic Liquids ◽  
Co2 Capture ◽  
Tertiary Amine ◽  
Adduct Formation ◽  
Lithium Salts ◽  
Organic Base ◽  
Organic Bases ◽  
Amine Functionalized ◽  
Neutral Ligands ◽  
Cation Coordination

Highly efficient CO2 absorption was realized through formation of zwitterionic adducts, combining synthetic strategies to ionic liquids (ILs) and coordination. The essence of our strategy is to make use of multidentate cation coordination between Li+ and an organic base. Also PEG-functionalized organic bases were employed to enhance the CO2-philicity. The ILs were reacted with CO2 to form the zwitterionic adduct. Coordination effects between various lithium salts and neutral ligands, as well as the CO2 capacity of the chelated ILs obtained were investigated. For example, the CO2 capacity of PEG150MeBu2N increased steadily from 0.10 to 0.66 (mol CO2 absorbed per mol of base) through the formation of zwitterionic adducts being stabilized by Li+.

scholarly journals Organocatalytic controlled/living ring-opening polymerization of cyclotrisiloxanes initiated by water with strong organic base catalysts

2018 ◽  
Vol 9 (11) ◽  
pp. 2879-2891 ◽  
Author(s):  
Keita Fuchise ◽  
Masayasu Igarashi ◽  
Kazuhiko Sato ◽  
Shigeru Shimada
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Organic Base ◽  
Base Catalysts ◽  
Organic Bases ◽  
Symmetric Structures

Organocatalytic controlled/living ring-opening polymerization of cyclotrisiloxanes using water as an initiator and strong organic bases as catalysts produced a variety of linear polysiloxanes with narrow polydispersity and well-defined symmetric structures.

Lipopolysaccharide Embedded within the Exine of Pollen Grains

1975 ◽  
Vol 33 ◽  
pp. 572-573 ◽  
Author(s):  
J. R. Rowley
Keyword(s):  
High Temperatures ◽  
Oral Presentation ◽  
Pollen Grains ◽  
Carboxyl Groups ◽  
Organic Base ◽  
Anionic Sites ◽  
Basic Dyes

Recent observations indicate that sporopollenin cannot any longer be considered as the only major component of the exine. Filaments in great numbers are exposed from exines of Lycopodium spores heated to high temperatures and sporopollenin partially dissolved. The filaments have closely spaced anionic sites whereas sporopollenin is composed only of C, H, and O and is without carboxyl groups to explain the basophilia typical of exines. The exposed filaments of Lycopodium spore exines are similar in their resistance to the organic base 2-aminoethanol, reaction to basic dyes, and in morphology to lipopolysaccharide extracted from exines of Epilgbium pollen (Rowley, abst. & oral presentation for Scand. Soc. of E.M., Umea 1973).To isolate lipopolysaccharide (LPS), exines were dissolved in 2-aminoethanol at 130-140°C for 18 hrs. Following dialysis the residue was extracted with 45% aqueous phenol at 65-68°C. The large aggregates of LPS in water were separated from other non-dialysiable substances by ultracentrifugation.

Cytochemical analysis of mast cell granules after poly-dl-lysine action

1978 ◽  
Vol 36 (2) ◽  
pp. 278-279
Author(s):  
R. Courtoy ◽  
L.J. Simar ◽  
J. Christophe
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Chemical Compounds ◽  
Cellular Membrane ◽  
Thin Sections ◽  
Organic Bases ◽  
Ferric Thiocyanate ◽  
Cytochemical Analysis ◽  
Mast Cell Granule ◽  
Amine Liberation

Several chemical compounds induce amine liberation from mast cells but do not necessarily provoque the granule expulsion. For example, poly-dl-lysine induces modifications of the cellular membrane permeability which promotes ion exchange at the level of mast cell granules. Few of them are expulsed but the majority remains in the cytoplasm and appears less dense to the electrons. A cytochemical analysis has been performed to determine the composition of these granules after the polylysine action.We have previously reported that it was possible to demonstrate polyanions on epon thin sections using a cetylpyridinium ferric thiocyanate method. Organic bases are selectively stained with cobalt thiocyanate and the sulfhydryle groups are characterized with a silver methenamine reaction. These techniques permit to reveal the mast cell granule constituents, i.e. heparin, biogenic amines and basic proteins.

Reactivity of Montmorillonite Surfaces with Weak Organic Bases

1969 ◽  
Vol 33 (5) ◽  
pp. 818-818 ◽  
Author(s):  
M. M. Mortland ◽  
V. C. Farmer ◽  
J. D. Russell
Keyword(s):  
Organic Bases
Sign in / Sign up

Export Citation Format

Share Document