Gas phase ion molecule reactions of organometallic compounds; protonation of selected η6-arenetricarbonylchromium complexes and η6-cycloheptatriene complexes of the Group VI metals with various Brønsted acid reagent ions

Flavanones are one of the flavonoid group that has wide variety of applications such as a precursors in drug discovery. In the laboratory, flavanone is often synthesized from chalcone compounds. The conversion of chalcone to flavanone can be catalyzed by bronsted acid. The reaction mechanism for this process is proposed through the Michael addition reaction, however, the energetic details and the rate determining step for this reaction is not certainly known. This research aimed to investigate the reaction mechanism for chalcone-flavanone conversion with the present of bronsted acid as catalyst and also studied the effect of the solvent on the reaction energy profile with computational method. In this study, the modeling of the reaction mechanism for the said reaction was carried out using the DFT computational method with M06-2X functional. The computation was done both in the gas phase and in present of the solvent effect using the PCM models. The results showed that the mechanism of chalcone-flavanone conversion occurred in three steps which are protonation, cyclization, and then tautomerization. Based on these calculations, the rate determining step was the tautomerization reaction, which exhibited the same results with or without the solvent effects. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

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Gas-phase protolysis between a neutral Brønsted acid and a neutral Brønsted base?

Chemical Physics Letters ◽

10.1016/s0009-2614(98)00833-1 ◽

1998 ◽

Vol 293 (5-6) ◽

pp. 511-514 ◽

Cited By ~ 8

Author(s):

Javier Catalán ◽

José Palomar

Keyword(s):

Gas Phase ◽

Bronsted Acid ◽

Brønsted Acid ◽

Brönsted Acid ◽

Brønsted Base

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Chiral Brønsted acid catalysis

AccessScience ◽

10.1036/1097-8542.yb080150 ◽

2015 ◽

Keyword(s):

Acid Catalysis ◽

Bronsted Acid ◽

Brønsted Acid ◽

Brönsted Acid ◽

Chiral Bronsted Acid ◽

Bronsted Acid Catalysis

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Reactivity Trends in the Gas Phase Addition of Acetylene to N-protonated Aryl Radical Cations

10.26434/chemrxiv.13078334 ◽

2020 ◽

Author(s):

Oisin Shiels ◽

P. D. Kelly ◽

Cameron C. Bright ◽

Berwyck L. J. Poad ◽

Stephen Blanksby ◽

...

Keyword(s):

Gas Phase ◽

Ion Trap ◽

Radical Cations ◽

Rate Coefficients ◽

Similar Process ◽

Ion Molecule Reactions ◽

Aromatic Radicals ◽

Polycyclic Aromatic ◽

Gas Phase Ion ◽

Type Radical

<div> <div> <div> <p>A key step in gas-phase polycyclic aromatic hydrocarbon (PAH) formation involves the addition of acetylene (or other alkyne) to σ-type aromatic radicals, with successive additions yielding more complex PAHs. A similar process can happen for N- containing aromatics. In cold diffuse environments, such as the interstellar medium, rates of radical addition may be enhanced when the σ-type radical is charged. This paper investigates the gas-phase ion-molecule reactions of acetylene with nine aromatic distonic σ-type radical cations derived from pyridinium (Pyr), anilinium (Anl) and benzonitrilium (Bzn) ions. Three isomers are studied in each case (radical sites at the ortho, meta and para positions). Using a room temperature ion trap, second-order rate coefficients, product branching ratios and reaction efficiencies are reported. </p> </div> </div> </div>

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