Role of Substituent Position in Coumarin Derivatives during their Interaction with TiO2 Nano Particles

Jagadeeshwar, Nirupama M.; Khanapurmath, Netravati; Chougala, Lakkanna S.; Kulkarni, Manohar V.; Kadadevarmath, Jagadish S.

doi:10.1007/s10895-021-02706-3

Cited by 3 publications

(1 citation statement)

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“…Generally, substituents have a significant influence on the structure, stability, and electronic properties of the reactant's main skeleton, thus changing the reaction results. [50][51][52] However, this work has revealed that the substituents have little effect on the radical difunctionalizations of aryl ethylenes represented by styrene, indicating that this kind of reaction can be applied to the difunctionalization of styrenes with multiple substituents. Based on our calculations, although the solvent effect does not influence the energy barrier of the tautomerism of step 6 significantly, the existence of water changes the reaction mechanism during step 6 and significantly reduces its energy barrier.…”

Section: Discussionmentioning

confidence: 87%

A density functional theory study on the mechanism of simultaneous trifluoromethylation and oximation of aryl-substituted ethylenes

Wang

Lan

et al. 2022

Journal of Chemical Research

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The effects of different substituents, located at the para position of the aromatic ring and at the β-carbon atom of styrenes, on difunctionalizations involving trifluoromethylation and oxime formation are investigated, showing that the difunctionalization reaction has a good adaptability to such reactants containing a range of substituents. This is important in the actual production process. It was found that proton transfer in the final tautomerism step involving transformation of a nitroso intermediate into an oxime is the rate-limiting step. The solvent effect did not influence the rate-limiting step significantly. Compared with direct proton transfer in a vacuum, the energy barrier of the final tautomerism step decreased from 57.80 kcal mol−1 in vacuum to 12.98 kcal mol−1 in water occurring via mediated proton transfer, which declines by 77.5%. When water participates in the rate-limiting steps in organic solvents, the energy barrier also decreases significantly, which indicates that a small amount of water in the organic solvent is conducive to the reaction.

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Section: Discussionmentioning

confidence: 87%