Assessment of mechanistic hypotheses of 1,3-dipolar cycloaddition of (arylsulfonyl)allene to nitrilimines by DFT reactivity indices

The reactivity and regioselectivity of 1,3-dipolar cycloaddition reactions of aryl and heteroaryl nitrile oxides (1a–1c) with bicyclic monoterpenes (R)-(+)-a-pinene (2a) and (S)-(–)-b-pinene (2b) have been investigated by using density functional theory based on reactivity indices and activation energy calculations at the B3LYP/6-31G(d) level of theory in the gas phase. The potential energy surface analyses for both reactions are in agreement with the experimental observations. Moreover, our calculations on the geometries, bond orders, and global electron density transfers at the transition state structures shows that these 1,3- dipolar cycloaddition reactions occur via an asynchronous one-step mechanism.

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The Azide-Allene Dipolar Cycloaddition: Is DFT Able to Predict Site- and Regio-Selectivity?

Molecules ◽

10.3390/molecules26040928 ◽

2021 ◽

Vol 26 (4) ◽

pp. 928

Author(s):

Giorgio Molteni ◽

Alessandro Ponti

Keyword(s):

Transition State ◽

1H Nmr ◽

Computational Scheme ◽

Dipolar Cycloaddition ◽

Experimental Site ◽

Dipolar Cycloadditions ◽

Reactivity Indices ◽

One Step ◽

Experimental Findings ◽

Step Mechanism

The site- and regio-selectivity of thermal, uncatalysed 1,3-dipolar cycloadditions between arylazides and mono- or tetra-substituted allenes with different electronic features have been investigated by both conceptual (reactivity indices) and computational (M08-HX, ωB97X-D, and B3LYP) DFT approaches. Both approaches show that these cycloadditions follow a nonpolar one-step mechanism. The experimental site- and regio-selectivity of arylazides towards methoxycarbonyl- and sulfonyl-allenes as well as tetramethyl- and tetrafluoro-allenes was calculated by DFT transition state calculations, achieving semiquantitative agreement to both previous and novel experimental findings. From the mechanistic standpoint, 1H-NMR evidence of a methylene-1,2,3-triazoline intermediate reinforces the reliability of the computational scheme.

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Prediction of the regioselectivity of 1,3-dipolar cycloaddition reactions of nitrile oxides with 2(5H)-furanones using recent theoretical reactivity indices

Progress in Reaction Kinetics and Mechanism ◽

10.3184/146867817x1495476485032 ◽

2017 ◽

Keyword(s):

Dipolar Cycloaddition ◽

Cycloaddition Reactions ◽

Nitrile Oxides ◽

Reactivity Indices

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Computational study of the 1,3-dipolar cycloaddition between methyl 2-trifluorobutynoate and substituted azides in terms of reactivity indices and activation parameters

Journal of Molecular Graphics and Modelling ◽

10.1016/j.jmgm.2017.02.017 ◽

2017 ◽

Vol 73 ◽

pp. 143-151 ◽

Cited By ~ 4

Author(s):

Mohammed Salah ◽

Najia Komiha ◽

Oum Keltoum Kabbaj ◽

Rachida Ghailane ◽

Khadija Marakchi

Keyword(s):

Computational Study ◽

Activation Parameters ◽

Dipolar Cycloaddition ◽

Reactivity Indices

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Reactivity and mechanism of nucleophilic addition reaction of amine with alkene: A systematic DFT study

Mediterranean Journal of Chemistry ◽

10.13171/mjc811902924zlhbea ◽

2019 ◽

Vol 8 (1) ◽

pp. 25-29

Author(s):

Zouhair Lakbaibi ◽

Adil Jaafar ◽

Hicham Ben El Ayouchia ◽

Mohamed Tabyaoui ◽

Abdelghani Boussaoud

Keyword(s):

Dft Calculations ◽

Nucleophilic Addition ◽

Addition Reaction ◽

Dft Study ◽

Methane Sulfonate ◽

Reactivity Indices ◽

Nucleophilic Addition Reaction ◽

Systematic Understanding ◽

Dft Reactivity Indices ◽

Step Mechanism

The reactivity and mechanism of the nucleophilic addition reaction of diethylamine 1 and 1-cyano-2-phenylvinyl methane sulfonate 2 have been studied for systematic understanding of this relevant organic transformation, using DFT calculations method at the B3LYP/6-311G(d,p) computational levels. Analysis of the conceptual DFT reactivity indices allows explaining the reactivity, and the calculated nucleophilic and electrophilic Parr functions at the reactive sites of reagents 1 and 2, respectively, allows explaining correctly the regioselectivity observed experimentally. The study has also been applied to predict the mechanism of amine with alkene. Interestingly, the study predicts a switch to a two-step mechanism due to the higher polar character of this zw-type nucleophilic addition reaction.

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Prediction of the Regioselectivity of 1,3-Dipolar Cycloaddition Reactions of Nitrile Oxides with 2(5H)-Furanones Using Recent Theoretical Reactivity Indices

Progress in Reaction Kinetics and Mechanism ◽

10.3184/146867817x14954764850324 ◽

2017 ◽

Vol 42 (3) ◽

pp. 289-299 ◽

Cited By ~ 1

Author(s):

Imad Eddine Charif ◽

Wafaa Benchouk ◽

Sidi Mohamed Mekelleche

Keyword(s):

Density Functional ◽

Basis Set ◽

Dipolar Cycloaddition ◽

Cycloaddition Reactions ◽

Functional Theory ◽

Nitrile Oxides ◽

Reactivity Indices ◽

Nucleophilic Reactivity ◽

Global And Local ◽

Electrophilic Site

The regioselectivity of a series of 16 1,3-dipolar cycloaddition reactions of nitrile oxides with 2(5 H)-furanones has been analysed by means of global and local electrophilic and nucleophilic reactivity indices using density functional theory at the B3LYP level together with the 6-31G(d) basis set. The local electrophilicity and nucleophilicity indices, based on Fukui and Parr functions, have been calculated for the terminal sites, namely the C1 and O3 atoms of the 1,3-dipole and the C4 and C5 atoms of the dipolarophile. These local indices were calculated using both Mulliken and natural charges and spin densities. The results obtained show that the C5 atom of the 2(5 H)-furanones is the most electrophilic site whereas the O3 atom of the nitrile oxides is the most nucleophilic centre. It turns out that the experimental regioselectivity is correctly reproduced, indicating that both Fukui- and Parr-based indices are efficient tools for the prediction of the regiochemistry of the studied reactions and could be used for the prediction of new designed reactions of the same kind.

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Synthesis of Some Pyrimidine, Pyrazole, and Pyridine Derivatives and Their Reactivity Descriptors

Journal of Chemistry ◽

10.1155/2018/8795061 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Nour E. A. Abd El-Sattar ◽

Eman H. K. Badawy ◽

M. S. A. Abdel-Mottaleb

Keyword(s):

Proton Transfer ◽

Gas Phase ◽

Electronic Structures ◽

Density Functional ◽

Keto Form ◽

Functional Theory ◽

Reactivity Descriptors ◽

Reactivity Indices ◽

Dft Reactivity Indices ◽

Theory Framework

A series of novel pyrimidine (2, 3), pyrazole (4, 5), and pyridine (6) derivatives were synthesized using a chalcone-bearing thiophene nucleus (1). The target compounds were synthesized by reaction of compound (1) with urea, thiourea, malononitrile, hydrazine hydrate, and 2,4-dinitrophenyl hydrazine, respectively. Molecular electronic structures have been modeled within density functional theory framework (DFT). Reactivity indices and electrostatic surface potential maps (ESP maps) allow us to establish trends that enable making predictions about chemical characteristics of the newly synthesized molecules and their proton transfer tautomers. Proton transfer is generally more favored in solution than in the gas phase. In acetonitrile, keto-form tautomers and thione-form tautomers become more energetically stable than the corresponding enol or thiol tautomers due to solvent-induced enhancement in the molecular polarity identified by computed dipole moment.

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