scholarly journals Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

2020 ◽  
Vol 16 ◽  
pp. 818-832 ◽  
Author(s):  
Péter Bagi ◽  
Réka Herbay ◽  
Nikolett Péczka ◽  
Zoltán Mucsi ◽  
István Timári ◽  
...  
Keyword(s):  
Double Bond ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Methanesulfonic Acid ◽  
Thermal Conditions ◽  
Double Bond Migration ◽  
Bond Rearrangement ◽  
Migration Pathways

A series of 1-substituted-3-methyl-2-phospholene oxides was prepared from the corresponding 3-phospholene oxides by double bond rearrangement. The 2-phospholene oxides could be obtained by heating the 3-phospholene oxides in methanesulfonic acid, or via the formation of cyclic chlorophosphonium salts. Whereas mixtures of the 2- and 3-phospholene oxides formed, when the isomerization of 3-phospholene oxides was attempted under thermal conditions, or in the presence of a base. The mechanisms of the various double bond migration pathways were elucidated by quantum chemical calculations.

Strukur und Reaktivität von Al2Cp*+ in der Gasphase. Ein experimenteller Beitrag zur Problematik der Aluminium-Aluminium- Doppelbindung / Structure and Reactivity of Al2Cp*+ in the Gas Phase. Experiments on the Problematic Nature of the Aluminum-Aluminum-Multiple Bond

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1512-1518 ◽  
Author(s):  
K. Koch ◽  
H. Schnöckel
Keyword(s):  
Double Bond ◽  
Gas Phase ◽  
Quantum Chemical Calculations ◽  
Mass Spectrometer ◽  
Quantum Chemical ◽  
Multiple Bond ◽  
New Approach ◽  
Existence And Stability ◽  
Ft Icr

The cation Al2Cp*+ descending from the tetrahedral Al4Cp*4 Cluster after using LDI as ionisation method in an FT-ICR mass spectrometer reacts with Cl2 in the gas phase. The investigation of this reaction together with quantum chemical calculations gives a new approach to the question of existence and stability of an aluminum-aluminum double bond.

Reactions directed towards the synthesis of 5-(β-hydroxyethyl)-2-isopropylcyclohexanone

1978 ◽  
Vol 31 (7) ◽  
pp. 1629 ◽  
Author(s):  
R Murphy ◽  
R Prager
Keyword(s):  
Double Bond ◽  
Partial Migration ◽  
Reaction Conditions ◽  
Double Bond Migration ◽  
Bond Rearrangement

Reduction of perillaldehyde by lithium in ammonia gives products the structures of which depend on reaction conditions. Shisool (p-menth-8- en-7-ol) undergoes double-bond migration in the presence of acids. The corresponding aldehyde, with dimethylsulfonium methylide, forms an oxiran which is comparatively unreactive, double-bond rearrangement or reduction accompanying the opening of the oxiran. The conversion of shisool into 5-(β-hydroxyethyl)-2-isopropylcyclohexanone was frustrated by only partial migration of the double bond.

Photochemische (2 + 2) Cycloadditionen an die C=N Doppelbindung — eine theoretische Untersuchung zur Regioselektivität

1985 ◽  
Vol 40 (3) ◽  
pp. 279-282 ◽  
Author(s):  
Walter Fabian
Keyword(s):  
Double Bond ◽  
Ab Initio ◽  
Quantum Chemical Calculations ◽  
Molecular Orbital ◽  
Quantum Chemical ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
Experimental Findings

Based on quantum chemical calculations (INDO/S and ab initio) the remarkable regioselectivity observed with the photochemical (2 + 2) cycloaddition of olefins to the C=N double bond is interpreted by means of perturbational molecular orbital theory. In each case the predictions concerning the most favourable regioisomer are completely in agreement with experimental findings.

Quantum chemical study of the charged gold atom influence on the mechanism of allylbenzene double bond migration

2011 ◽  
Vol 60 (8) ◽  
pp. 1545-1555 ◽  
Author(s):  
D. F. Mukhamedzyanova ◽  
D. A. Pichugina ◽  
M. S. Askerka ◽  
A. F. Shestakov ◽  
N. E. Kuz’menko
Keyword(s):  
Double Bond ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Gold Atom ◽  
Chemical Study ◽  
Double Bond Migration

Discovery of a Difluoroglycine Synthesis Method through Quantum Chemical Calculations

2020 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Yu Harabuchi ◽  
Satoshi Maeda
Keyword(s):  
Quantum Chemical Calculations ◽  
Experimental Verification ◽  
Quantum Chemical ◽  
Synthesis Method ◽  
Target Product ◽  
Systematic Exploration ◽  
Hands On ◽  
Retrosynthetic Analysis ◽  
Synthetic Routes ◽  
Verification Process

The systematic exploration of synthetic pathways to afford a desired product through quantum chemical calculations remains a considerable challenge. In 2013, Maeda et al. introduced ‘quantum chemistry aided retrosynthetic analysis’ (QCaRA), which uses quantum chemical calculations to search systematically for decomposition paths of the target product and propose a synthesis method. However, until now, no new reactions suggested by QCaRA have been reported to lead to experimental discoveries. Using a difluoroglycine derivative as a target, this study investigated the ability of QCaRA to suggest various synthetic paths to the target without relying on previous data or the knowledge and experience of chemists. Furthermore, experimental verification of the seemingly most promising path led to the discovery of a synthesis method for the difluoroglycine derivative. The extent of the hands-on expertise of chemists required during the verification process was also evaluated. These insights are expected to advance the applicability of QCaRA to the discovery of viable experimental synthetic routes.

Discovery of a Difluoroglycine Synthesis Method through Quantum Chemical Calculations

2020 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Yu Harabuchi ◽  
Satoshi Maeda
Keyword(s):  
Quantum Chemical Calculations ◽  
Experimental Verification ◽  
Quantum Chemical ◽  
Synthesis Method ◽  
Target Product ◽  
Systematic Exploration ◽  
Hands On ◽  
Retrosynthetic Analysis ◽  
Synthetic Routes ◽  
Verification Process

The systematic exploration of synthetic pathways to afford a desired product through quantum chemical calculations remains a considerable challenge. In 2013, Maeda et al. introduced ‘quantum chemistry aided retrosynthetic analysis’ (QCaRA), which uses quantum chemical calculations to search systematically for decomposition paths of the target product and propose a synthesis method. However, until now, no new reactions suggested by QCaRA have been reported to lead to experimental discoveries. Using a difluoroglycine derivative as a target, this study investigated the ability of QCaRA to suggest various synthetic paths to the target without relying on previous data or the knowledge and experience of chemists. Furthermore, experimental verification of the seemingly most promising path led to the discovery of a synthesis method for the difluoroglycine derivative. The extent of the hands-on expertise of chemists required during the verification process was also evaluated. These insights are expected to advance the applicability of QCaRA to the discovery of viable experimental synthetic routes.

The Nature of Chemisorbed CO2 in Zeolite A

2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski
Keyword(s):  
Solid State ◽  
Ir Spectroscopy ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Surface Coverage ◽  
Gas Mixtures ◽  
Mas Nmr ◽  
Significant Fraction ◽  
Zeolite A

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.

Mechanistic Investigation of Rh(I)-Catalyzed Asymmetric Suzuki-Miyaura Coupling with Racemic Allyl Halides

2019 ◽  
Author(s):  
Lucy van Dijk ◽  
Ruchuta Ardkhean ◽  
Mireia Sidera ◽  
Sedef Karabiyikoglu ◽  
Özlem Sari ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Experimental Studies ◽  
Mechanistic Investigation ◽  
Allyl Halides

A mechanism for Rh(I)-catalyzed asymmetric Suzuki-Miyaura coupling with racemic allyl halides is proposed based on a combination of experimental studies and quantum chemical calculations. <br>

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