Gold-catalyzed [4+1]-annulation reactions between anthranils and 4-methoxy-1,2-dienyl-5-ynes involving a 1,2-allene shift

2019 ◽  
Vol 55 (13) ◽  
pp. 1979-1982 ◽  
Author(s):  
Hsiang-Chu Hsieh ◽  
Kuo-Chen Tan ◽  
Antony Sekar Kulandai Raj ◽  
Rai-Shung Liu
Keyword(s):  
Reaction Mechanism ◽  
Initial Formation

Gold catalyzed [4+1]-annulations of 4-methoxy-1,2-dien-5-ynes with anthranils are described; the reaction mechanism involves initial formation of α-imino gold carbenes, followed by a subsequent 1,2-allene shift.

ÉTARD REACTION: III. NATURE OF THE COMPLEX

1960 ◽  
Vol 38 (11) ◽  
pp. 2136-2142 ◽  
Author(s):  
Owen H. Wheeler
Keyword(s):  
Magnetic Susceptibility ◽  
Reaction Mechanism ◽  
Chloride Complex ◽  
Initial Formation ◽  
Spectroscopic Evidence ◽  
Chromyl Chloride ◽  
Π Complex ◽  
Products Of Reaction

Magnetic susceptibility measurements have shown that the chromium atoms in the toluene–chromyl chloride complex are tetravalent. The structure of the complex and the reaction mechanism are discussed. Spectroscopic evidence has been found of the initial formation of a π-complex. The products of reaction of chromyl chloride and ethylbenzene, isopropylbenzene, tetralin, and indane have been determined.

Arylation of enelactams using TIPSOTf: reaction scope and mechanistic insight

2021 ◽  
Author(s):  
Tomasz J. Idzik ◽  
Zofia M. Myk ◽  
Łukasz Struk ◽  
Magdalena Perużyńska ◽  
Gabriela Maciejewska ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Multinuclear Nmr ◽  
Mechanistic Insight ◽  
Nmr Study ◽  
Wide Range

Triisopropylsilyltrifluoromethanesulfonate can be effectively used for the arylation of a wide range of enelactams. The multinuclear NMR study provided deep insights into the reaction mechanism.

Theoretical study of the ketonization reaction mechanism of acetic acid over SiO2

2009 ◽  
Author(s):  
Mendel Fleisher ◽  
E. Lukevics ◽  
L. Leite ◽  
D. Jansone ◽  
K. Edolfa ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Theoretical Study

DIE INITIALE VERTEILUNG VON RADIO-C IN DEN ZELLFRAKTIONEN EINIGER RATTENORGANE NACH INJEKTION VON TESTOSTERON-4-14C

1964 ◽  
Vol 47 (1) ◽  
pp. 51-57 ◽  
Author(s):  
K.-O. Mosebach ◽  
W. Dirscherl
Keyword(s):  
Intraperitoneal Injection ◽  
Specific Activity ◽  
Initial Distribution ◽  
Male Rats ◽  
Initial Formation ◽  
Thigh Muscles ◽  
The Absolute ◽  
Cell Fractions

ABSTRACT The initial distribution of radioactive C was studied in the cell fractions of the liver, kidney, testes and thigh muscles after intraperitoneal injection of testosterone-4-14C into 40 day old male rats. To make this possible, the absolute and specific activity values (μc/mg C) were determined. After both ten and twenty minutes the cytoplasm fractions possessed the highest activity values, the only exception being the specific activity of the liver cytoplasm ten minutes after injection when the microsomes of the liver showed a higher activity. After 20 min the mitochondria possessed the highest specific activity values among the corpuscular fractions. The specific activity values in the microsomes of all four organs studied were lower 20 min after the time of injection than after 10 min, a fact, which is suspected to be the result of the initial formation of conjugates in the microsomes.

OPTIMIZATION OF A SURROGATE REDUCED AVIATION FUEL-AIR REACTION MECHANISM USING A GENETIC ALGORITHM

Clean Air ◽  
2007 ◽  
Vol 8 (1) ◽  
pp. 1-24
Author(s):  
M. Pourkashanian ◽  
N. S. Mera ◽  
Lionel Elliott ◽  
C. W. Wilson ◽  
Derek B. Ingham ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Reaction Mechanism ◽  
Aviation Fuel

LA PARTICIPACIÓN CIUDADANA Y EL DESARROLLO DE LA CULTURA CIENTÍFICA, EN LA FORMACIÓN INICIAL DEL PROFESOR PARA LA EDUCACIÓN TÉCNICA Y PROFESIONAL. UN RETO HECHO REALIDAD.

2015 ◽  
Vol 3 (3) ◽  
Author(s):  
María Isabel Orozco Rivero
Keyword(s):  
Citizen Participation ◽  
Professional Education ◽  
Theory And Practice ◽  
Scientific Development ◽  
Scientific Culture ◽  
Initial Formation ◽  
Theoretical Contribution ◽  
Palabras Clave ◽  
Stated Problem ◽  
Theoretical Foundations

La formación inicial del profesor de la Educación Técnica y Profesional (ETP), debe estar en correspondenciacon la integración del conocimiento científico, el acelerado desarrollo de la ciencia y la tecnologíay las exigencias en la formación de las nuevas generaciones. Esta investigación aborda la problemáticaplanteada en la formación de profesores para la Carrera de Informática y asume como problemacientífico: “¿Cómo contribuir al desarrollo de una cultura científica como base para una participaciónciudadana responsable, en la formación inicial del profesor para la ETP en la Carrera Informática?”. La metodología utilizada constituye una integración de métodos teóricos y empíricos, lo que permitióla elaboración de la propuesta. Se trabajan y sustentan los antecedentes teóricos y metodológicos delproceso de formación inicial del profesor para la Educación Técnica y Profesional. Finalmente, se brindan los resultados de la aplicación de la consulta a expertos como comprobación teórica del mismo ysu aplicación parcial en la práctica. El fundamento teórico y las relaciones sistemáticas que se establecenentre los componentes, constituyen el principal aporte teórico y novedad de la investigación.   Palabras Clave: participación ciudadana, cultura científica, formación inicial, educación técnica y profesional.   ABSTRACT   The basic formation of teachers in Technical and Professional Education (TPE) must be in correspondencewith the integration of scientific development, the accelerated development of science and technology, and the educational demands of the new generations.  This research addresses the stated problem in the formation of teachers for the Informatics Career and assumes the scientific problem: How to contribute to thedevelopment of a scientific culture as the basis of a responsible citizen participation, in the initial formation of the ETP teacher in the Informatics Career? The methodology used integrates both theoretical and empiricalmethods which helped to build up this proposal.  Historical and methodological background of the formation process are worked out and supported.  Finally, results of the application of expert consulting as averification in theory and practice. The theoretical foundations and the systematic relationships established among the components constitute the main theoretical contribution and novelty of this research.   Keywords: citizen participation, scientific culture, initial formation, technical and professional education   Recibido: julio de 2015Aprobado: septiembre de 2015

Ligand-Enabled γ-C(sp3)–H Olefination of Free Carboxylic Acids

2020 ◽  
Author(s):  
Kiron Kumar Ghosh ◽  
Alexander Uttry ◽  
Francesca Ghiringhelli ◽  
Arup Mondal ◽  
Manuel van Gemmeren
Keyword(s):  
Reaction Mechanism ◽  
Carboxylic Acids ◽  
Michael Addition ◽  
Kinetic Studies ◽  
Wide Range ◽  
Palladium Catalyzed

We report the ligand enabled C(sp3)–H activation/olefination of free carboxylic acids in the γ-position. Through an intramolecular Michael-addition, δ-lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium-catalyzed activation of free carboxylic acids in the γ-position. The developed protocol features a wide range of acid substrates and olefin reaction partners and is shown to be applicable on a preparatively useful scale. Insights into the underlying reaction mechanism obtained through kinetic studies are reported.<br>

Reactions of an Aluminium(I) Reagent with 1,2-, 1,3- and 1,5-Dienes: Dearomatisation, Reversibility, and a Pericyclic Mechanism

2019 ◽  
Author(s):  
Clare Bakewell ◽  
Martí Garçon ◽  
Richard Y Kong ◽  
Louisa O'Hare ◽  
Andrew J. P. White ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Transition State ◽  
Reaction Pathways ◽  
Aromatic Rings ◽  
Aromatic Character ◽  
Pericyclic Reaction

The reactions of an aluminium(I) reagent with a series of 1,2-, 1,3- and 1,5-dienes are reported. In the case of 1,3-dienes the reaction occurs by a pericyclic reaction mechanism, specifically a cheletropic cycloaddition, to form aluminocyclopentene containing products. This mechanism has been interrogated by stereochemical experiments and DFT calculations. The stereochemical experiments show that the (4+1) cycloaddition follows a suprafacial topology, while calculations support a concerted albeit asynchronous pathway in which the transition state demonstrates aromatic character. Remarkably, the substrate scope of the (4+1) cycloaddition includes dienes that are either in part, or entirely, contained within aromatic rings. In these cases, reactions occur with dearomatisation of the substrate and can be reversible. In the case of 1,2- or 1,5-dienes complementary reactivity is observed; the orthogonal nature of the C=C π-bonds (1,2-diene) and the homoconjugated system (1,5-diene) both disfavour a (4+1) cycloaddition. Rather, reaction pathways are determined by an initial (2+1) cycloaddition to form an aluminocyclopropane intermediate which can in turn undergo insertion of a further C=C π-bond leading to complex organometallic products that incorporate fused hydrocarbon rings.

A Paramedic Treatment for Modeling Explicitly Solvated Chemical Reaction Mechanisms

2018 ◽  
Author(s):  
Yasemin Basdogan ◽  
John Keith
Keyword(s):  
Reaction Mechanism ◽  
Chemical Reaction ◽  
Reaction Mechanisms ◽  
Reaction Pathway ◽  
Optimization Procedure ◽  
Cost Effective ◽  
Chemical Reaction Mechanisms ◽  
Solvent Molecules ◽  
Dynamics Simulations ◽  
Mbh Reaction

<div> <div> <div> <p>We report a static quantum chemistry modeling treatment to study how solvent molecules affect chemical reaction mechanisms without dynamics simulations. This modeling scheme uses a global optimization procedure to identify low energy intermediate states with different numbers of explicit solvent molecules and then the growing string method to locate sequential transition states along a reaction pathway. Testing this approach on the acid-catalyzed Morita-Baylis-Hillman (MBH) reaction in methanol, we found a reaction mechanism that is consistent with both recent experiments and computationally intensive dynamics simulations with explicit solvation. In doing so, we explain unphysical pitfalls that obfuscate computational modeling that uses microsolvated reaction intermediates. This new paramedic approach can promisingly capture essential physical chemistry of the complicated and multistep MBH reaction mechanism, and the energy profiles found with this model appear reasonably insensitive to the level of theory used for energy calculations. Thus, it should be a useful and computationally cost-effective approach for modeling solvent mediated reaction mechanisms when dynamics simulations are not possible. </p> </div> </div> </div>

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