scholarly journals Direct electrochemical hydrodefluorination of trifluoromethylketones enabled by non-protic conditions

2021 ◽  
Author(s):  
John R. Box ◽  
Alexander P. Atkins ◽  
Alastair J. J. Lennox
Keyword(s):  
Single Step ◽  
Single Step Reaction

The electrochemical hydrodefluorination of trifluoromethylketones under non-protic conditions make this single-step reaction at deeply reductive potentials uniquely amenable to challenging electron-rich substrates and reductively sensitive functionalities.

Computational Study on the Kinetics and Mechanisms of Unimolecular Reactions of (Z)-(Z)-N-(λ5-phosphanylidene) Formohydrazonic Formic Anhydride: Intramolecular aza-Wittig Reaction in Competition with Mumm Rearrangement

2020 ◽  
Vol 17 (11) ◽  
pp. 884-889
Author(s):  
Somayeh Mirdoraghi ◽  
Hamed Douroudgari ◽  
Farideh Piri ◽  
Morteza Vahedpour
Keyword(s):  
Rate Constants ◽  
Density Functional ◽  
Wittig Reaction ◽  
Computational Study ◽  
Single Step ◽  
Low Energy ◽  
Coupled Cluster ◽  
Unimolecular Reaction ◽  
Single Step Reaction ◽  
Good Agreement

For (Z)-(Z)-N-(λ5-phosphanylidene) formohydrazonic formic anhydride, Aza-Wittig reaction and Mumm rearrangement are studied using both density functional and coupled cluster theories. For this purpose, two different products starting from one substrate are considered that are competing with each other. The obtained products, P1 and P2, are thermodynamically favorable. The product of the aza-Wittig reaction, P1, is more stable than the product of Mumm rearrangement (P2). For the mentioned products, just one reliable pathway is separately proposed based on unimolecular reaction. Therefore, the rate constants based on RRKM theory in 300-600 K temperature range are calculated. Results show that the P1 generation pathway is a suitable path due to low energy barriers than the path P2. The first path has three steps with three transition states, TS1, TS2, and TS3. The P2 production path is a single-step reaction. In CCSD level, the computed barrier energies are 14.55, 2.196, and 10.67 kcal/mol for Aza-Wittig reaction and 42.41 kcal/mol for Mumm rearrangement in comparison with the corresponding complexes or reactants. For final products, the results of the computational study are in a good agreement with experimental predictions.

scholarly journals Kinetics of solvolysis in water of four secondary alkyl nitrates

1982 ◽  
Vol 60 (13) ◽  
pp. 1780-1785 ◽  
Author(s):  
Ross Elmore Robertson ◽  
Kalvelil Matthew Koshy ◽  
Adrianne Annessa ◽  
Jan N. Ong ◽  
John Marshall William Scott ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Rate Constant ◽  
Analytical Methods ◽  
Kinetic Data ◽  
Activation Parameters ◽  
Single Step ◽  
Alkyl Nitrates ◽  
Two Stage ◽  
Kinetics Of ◽  
Single Step Reaction

Kinetic data are reported for the solvolysis in water of propane-2-nitrate, butane-2-nitrate, cyclopentyl nitrate, and cyclohexyl nitrate. In each case, the dependence of rate constant on temperature is analysed in terms of two mechanisms for the solvolytic reaction. First it is assumed that the rate constant describes a single step reaction, the analysis leading to estimates of the heat capacity of activation ΔCp≠. Three different analytical methods are discussed in this regard. Second it is assumed that the rate constant describes a two stage mechanism, the first stage being reversible. In this case the explanation of the ΔCp≠ term calculated according to the first mechanism is quite different. We comment on the alternative explanations of trends in activation parameters.

scholarly journals Crystal structure of 2-(4-chlorophenyl)-2-oxoethyl 3-bromobenzoate

2014 ◽  
Vol 70 (11) ◽  
pp. 301-304 ◽  
Author(s):  
Imtiaz Khan ◽  
Aliya Ibrar ◽  
Shahid Hameed ◽  
Jonathan M. White ◽  
Jim Simpson
Keyword(s):  
Crystal Structure ◽  
Single Step ◽  
Stacking Interactions ◽  
Axis Direction ◽  
Π Stacking ◽  
Methylene Group ◽  
Single Step Reaction ◽  
Aryl Ester ◽  
Aryl Ketone

2-(4-Chlorophenyl)-2-oxoethyl 3-bromobenzoate, C15H10BrClO3, was synthesized in a single-step reaction by condensation of 3-bromobenzoic acid with 2-bromo-1-(4-chlorophenyl)ethanone in dimethylformamide in the presence of triethylamine as a catalyst. The structure consists of an aryl ketone moiety linked to an aryl ester unit by a methylene group. Both units are reasonably planar (r.m.s. deviations of 0.119 and 0.010 Å for the aryl ketone and aryl ester units, respectively) and are almost orthogonal, with an angle of 88.60 (3)° between them. In the crystal, molecules form five separate sets of inversion dimers. Three of these are generated by two C—H...O interactions and a C—H...Br contact, and form chains alongcand along theabcell diagonal. In addition, two inversion-related π–π stacking interactions between like aryl rings again form chains of molecules but in this instance along thebcdiagonal. These contacts generate infinite layers of molecules parallel to (011) and stack the molecules along thea-axis direction.

scholarly journals Preparation of Renewable Bio-Polyols from Two Species of Colliguaja for Rigid Polyurethane Foams

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2244 ◽  
Author(s):  
Diana Abril-Milán ◽  
Oscar Valdés ◽  
Yaneris Mirabal-Gallardo ◽  
Alexander F. de la Torre ◽  
Carlos Bustamante ◽  
...  
Keyword(s):  
Iodine Value ◽  
Chromatographic Analysis ◽  
Kinematic Viscosity ◽  
Acid Value ◽  
Single Step ◽  
Polyurethane Foams ◽  
Edible Oil ◽  
Raw Material ◽  
Hydroxyl Number ◽  
Single Step Reaction

In this study, we investigated the potential of two non-edible oil extracts from seeds of Colliguaja integerrima (CIO) and Colliguaja salicifolia (CSO) to use as a renewable source for polyols and, eventually, polyurethane foams or biodiesel. For this purpose, two novel polyols from the aforementioned oils were obtained in a one-single step reaction using a mixture of hydrogen peroxide and acetic acid. The polyol derivatives obtained from the two studied oils were characterized by spectral (FTIR, 1H NMR, and 13C NMR), physicochemical (e.g., chromatographic analysis, acid value, oxidizability values, iodine value, peroxide value, saponification number, kinematic viscosity, density, theorical molecular weight, hydroxyl number, and hydroxyl functionality) and thermal (TGA) analyses according to standard methods. Physicochemical results revealed that all parameters, with the exception of the iodine value, were higher for bio-polyols (CSP and CIP) compared to the starting oils. The NMR, TGA, and FTIR analyses demonstrated the formation of polyols. Finally, the OH functionality values for CIP and CSP were 4.50 and 5.00, respectively. This result indicated the possible used of CIP and CSP as a raw material for the preparation of polyurethane rigid foams.

Alternariol: evidence for biosynthesis via norlichexanthone

1986 ◽  
Vol 64 (8) ◽  
pp. 1590-1594 ◽  
Author(s):  
E. E. Stinson ◽  
W. B. Wise ◽  
R. A. Moreau ◽  
A. J. Jurewicz ◽  
P. E. Pfeffer
Keyword(s):  
Bond Cleavage ◽  
Single Step ◽  
Polyketide Chain ◽  
Aflatoxin B ◽  
Single Step Reaction

Alternaria molds produce numerous mycotoxins including many α-dibenzopyrones such as alternariol (AOH) and related polyketides. AOH, presumed to be the initial α-dibenzopyrone produced, has for 20 years been considered to be biosynthesized from a single polyketide chain in a single step reaction. The present study presents evidence that the reaction may proceed through an intermediate, norlichexanthone (NLX). Bond cleavage and rearrangement of NLX to form AOH may be similar to aflatoxin B1 formation from sterigmatocystin. The 2-D INADEQUATE experiment was used to assign the 13C spectrum of AOH and to distinguish between possible mechanisms by which AOH may be synthesized from 1-13C and 2-13C acetates via NLX.

Eutectic melt crystallization of L10-FePt

2019 ◽  
Vol 55 (5) ◽  
pp. 656-658 ◽  
Author(s):  
Jingming Zhang ◽  
Changning Li ◽  
Jason Armstrong ◽  
Shenqiang Ren
Keyword(s):  
Growth Control ◽  
Eutectic Growth ◽  
Single Step ◽  
Melt Crystallization ◽  
Single Step Reaction ◽  
Eutectic Melt ◽  
Nucleation Growth

Herein, we report the eutectic growth control of ordered L10-FePt, which directs the nucleation, growth and crystallization of FePt sheets in a single-step reaction.

A Single-Step Reaction for Silicon and Germanium Nanorods

2014 ◽  
Vol 20 (20) ◽  
pp. 5874-5879 ◽  
Author(s):  
Xiaotang Lu ◽  
Brian A. Korgel
Keyword(s):  
Single Step ◽  
Silicon And Germanium ◽  
Single Step Reaction

scholarly journals Synthesis, Characterization, and Biological Activity of 5-Phenyl-1,3,4-thiadiazole-2-amine Incorporated Azo Dye Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Chinnagiri T. Keerthi Kumar ◽  
Jathi Keshavayya ◽  
Tantry N. Rajesh ◽  
Sanehalli K. Peethambar ◽  
Angadi R. Shoukat Ali
Keyword(s):  
Biological Activity ◽  
Sulphuric Acid ◽  
Elemental Analysis ◽  
Azo Dye ◽  
Single Step ◽  
H Nmr ◽  
Single Step Reaction ◽  
C Nmr

5-Phenyl-1,3,4-thiadiazole-2-amine has been synthesized by single step reaction. A series of heterocyclic azodyes were synthesized by diazotisation of 5-phenyl-1,3,4-thiadiazole-2-amine by nitrosyl sulphuric acid followed by coupling with different coupling compounds such as 8-hydroxyquinoline, 2,6-diaminopyridine, 2-naphthol, N,N-dimethyl aniline, resorcinol, and 4,6-dihydroxypyrimidine. The dyes were characterized by UV-Vis, IR, 1H-NMR, 13C NMR, and elemental analysis. The synthesized compounds were also screened for biological activity.

Stannic tetrachloride catalysed glycosylation of 8-ethoxycarbonyloctanol by cellobiose, lactose, and maltose octaacetates; synthesis of α- and β-glycosidic linkages

1979 ◽  
Vol 57 (16) ◽  
pp. 2085-2090 ◽  
Author(s):  
Joseph Banoub ◽  
David R. Bundle
Keyword(s):  
Good Yield ◽  
Room Temperature ◽  
Single Step ◽  
Carbohydrate Antigens ◽  
Single Step Reaction ◽  
Preparative Route

The 1,2-trans-octaacetates of cellobiose, lactose, and maltose were converted to β-glycosides of 8-ethoxycarbonyloctanol in good yield by a single step reaction. A 1,2-acetoxonium ion generated by stannic tetrachloride in dichloromethane at −10 °C leads initially to β-glycosides via 1,2-orthoacetate intermediates. Insitu anomerisation of the β-maltoside occurred during reaction (4 h) at room temperature and provided a preparative route to this α-glycoside of the disaccharide. The β-lactose and cellobiose glycosides were also anomerised to the respective α-glycosides. The three β- and three α-disaccharide glycosides of the disaccharides have been functionalised for conversion to artificial carbohydrate antigens.

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