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Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
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Understanding and Predicting Post H-Atom Abstraction Selectivity through Reactive Mode Composition Factor Analysis
Mauricio Maldonado-Domínguez1, Martin Srnec1
1J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences , Dolejškova 3 , Prague 8 18223 , Czech Republic.
Journal of the American Chemical Society
|February 1, 2020
Summary
Selective C-H bond functionalization is achieved by predicting post-H-atom abstraction (HAA) mechanisms. Reactive mode composition factor (RMCF) analysis reveals kinetic energy distribution signatures that dictate selectivity in high-valent iron-oxo reactions.
Area of Science:
- Synthetic organic chemistry
- Computational chemistry
- Reaction mechanism studies
Background:
- Selective C-H bond functionalization is a key challenge in synthetic chemistry.
- High-valent iron-oxo oxidants are potent tools for C-H activation.
- Understanding post-H-atom abstraction (HAA) pathways is crucial for controlling reaction outcomes.
Purpose of the Study:
- To elucidate the factors governing selectivity between OH-rebound and dissociation pathways after HAA.
- To develop a predictive model for reaction selectivity based on the HAA step.
- To investigate the role of kinetic energy distribution in determining reaction mechanisms.
Main Methods:
- Application of reactive mode composition factor (RMCF) analysis.
- Computational modeling of transition states and kinetic energy distributions.
- Analysis of H-atom abstraction (HAA) and subsequent reaction pathways.
Main Results:
- The selectivity of post-HAA mechanisms (OH-rebound vs. dissociation) is encoded in the HAA step.
- RMCF analysis reveals distinct kinetic energy distribution signatures for each pathway.
- Exergonic, electron transfer-driven HAA reactions favor the OH-rebound pathway.
Conclusions:
- Kinetic energy distribution at the transition state predicts post-HAA selectivity.
- H/D primary kinetic isotope effects can serve as experimental probes for these mechanisms.
- This work provides a fundamental understanding of selectivity in iron-catalyzed C-H functionalization.
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