In Quest of “Stereoselective Switch” for On-Water Hydrothiolation of Terminal Alkynes Using Different Additives and Green Synthesis of Vicinal Dithioethers

Basu, Basudeb; Biswas, Kinkar; Kundu, Samir; Sengupta, Debapriya

doi:10.1155/2014/358932

Cited by 4 publications

(1 citation statement)

References 55 publications

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“…1 Under thermal, photochemical or basic conditions, a mixture of (E/Z)anti -Markovnikov species has been reported. [7][8][9][10][11] Transition metal mediated reaction can bring in remarkable regio-as well as stereoselectivity. 3 Recently, organocatalyzed reactions have come to surpass metal catalyzed reactions in terms of cost effectiveness and environmental friendliness.…”

Section: Introductionmentioning

confidence: 99%

Computationally Unravelling the Mechanism and Selectivity of Five and Six membered N-Heterocyclic Carbene- Catalyzed Alkyne Hydrochalcogenation

Elambalassery¹,

Reshma²,

Aswathy³

2020

Preprint

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The present work is intended to bring to the forefront a relatively less explored area of N-Heterocyclic Carbene (NHC) catalyzed alkyne hydro- thiolation and selenation reactions. The present work can be regarded as the first ever computational investigation on the catalytic activity of the NHC catalyzed hydro- thiolation and selenation reactions by exploring the reaction mechanism. Reaction mechanism involves chalcogenol activation followed by alkyne insertion and the second step is found to be the rate determining step. A comparison with the reported uncatalyzed gas phase reaction showed that a simple imidazol-2-ylidene catalyst can lower the free energy barrier by 19.62 and 14.63 kcal/mol respectively for acetylene hydro- thiolation and selenation reaction. All the employed NHCs are proved to be better catalyst for both hydrothiolation and hydroselenation. Effects of factors such as changing the heterocycle, increasing the conjugation, ring expansion and electronic/steric substitution were also investigated. Effect of solvent polarity on the reaction energetics and selectivity has also been analyzed employing THF, DMSO and MeOH as the solvents.

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Section: Introductionmentioning

confidence: 99%

Computationally Unravelling the Mechanism and Selectivity of Five and Six membered N-Heterocyclic Carbene- Catalyzed Alkyne Hydrochalcogenation

Elambalassery¹,

Reshma²,

Aswathy³

2020

Preprint

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Computationally unraveling the mechanism and selectivity of five and six membered N‐heterocyclic carbene‐catalyzed alkyne hydrochalcogenation

Jayasree

Reshma

Aswathy

2021

Int J of Quantum Chemistry

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The present work is intended to bring to the forefront a relatively less explored area of N-Heterocyclic Carbene (NHC) catalyzed alkyne hydro-thiolation and selenation reactions by exploring the reaction mechanism. Reaction mechanism involves chalcogenol activation followed by alkyne insertion and the second step is the rate determining step. A comparison with the reported uncatalyzed gas phase reaction showed that a simple imidazol-2-ylidene catalyst can lower the free energy barrier by 28.74 and 21.73 kcal/mol respectively for acetylene hydro-thiolation and selenation reaction. All the employed NHCs are proved to be better catalyst for both hydrothiolation and hydroselenation. Factors such as changing the heterocycle, increasing the conjugation, ring expansion and electronic/steric substitution at the heteroatom were found to affect the energy barriers due to the geometric variations at NHCcarbon and S/Se in the intermediate and the transition structure corresponding to alkyne insertion. Effect of solvent polarity on the reaction energetics and selectivity has also been analyzed employing THF, DMSO and MeOH as the solvents.

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A computational study on the reaction mechanism and energetics of Markovnikov and anti-Markovnikov addition in alkyne hydrothiolation reactions

Jayasree

Reshma

2016

Computational and Theoretical Chemistry

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In Quest of “Stereoselective Switch” for On-Water Hydrothiolation of Terminal Alkynes Using Different Additives and Green Synthesis of Vicinal Dithioethers

Cited by 4 publications

References 55 publications

Computationally Unravelling the Mechanism and Selectivity of Five and Six membered N-Heterocyclic Carbene- Catalyzed Alkyne Hydrochalcogenation

Computationally Unravelling the Mechanism and Selectivity of Five and Six membered N-Heterocyclic Carbene- Catalyzed Alkyne Hydrochalcogenation

Computationally unraveling the mechanism and selectivity of five and six membered N‐heterocyclic carbene‐catalyzed alkyne hydrochalcogenation

A computational study on the reaction mechanism and energetics of Markovnikov and anti-Markovnikov addition in alkyne hydrothiolation reactions

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