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Molecule-induced alkane homolysis with dioxiranes
A A Fokin1, B A Tkachenko, O I Korshunov
1Department of Organic Chemistry, Kiev Polytechnic Institute, 37 Pobeda Avenue, 03056 Kiev, Ukraine.
Journal of the American Chemical Society
|November 8, 2001
Summary
Dimethyldioxirane (DMD) facilitates C-H and C-C bond activations in propellanes. This study reveals the first molecule-induced homolytic C-C bond cleavage and details C-H bond hydroxylation mechanisms.
Area of Science:
- Organic Chemistry
- Computational Chemistry
- Reaction Mechanisms
Background:
- Propellanes are strained polycyclic hydrocarbons with unique reactivity.
- Understanding C-H and C-C bond activation is crucial for synthetic chemistry.
- Dimethyldioxirane (DMD) is a powerful yet selective oxidizing agent.
Purpose of the Study:
- To investigate the mechanisms of C-H and C-C bond activations by DMD in propellanes.
- To compare the reactivity of different propellanes with DMD and chromium oxychloride (CrO2Cl2).
- To elucidate the energetic profiles and pathways of these activation processes.
Main Methods:
- Experimental studies combined with density functional theory (DFT) calculations.
- Utilized B3LYP/6-311+G**//B3LYP/6-31G* level of theory.
- Investigated reactions of 3,6-dehydrohomoadamantane (2) and 1,3-dehydroadamantane (3) with DMD and CrO2Cl2.
Main Results:
- The sigma(C-C) activation of 1,3-dehydroadamantane (3) with DMD represents the first example of molecule-induced homolytic C-C bond cleavage.
- C-H bond hydroxylation of 3,6-dehydrohomoadamantane (2) with DMD is highly exergonic and proceeds via a concerted pathway.
- Reactivity patterns with DMD and CrO2Cl2 show parallels for highly reactive propellanes but diverge for more stable ones.
Conclusions:
- DMD exhibits distinct mechanisms for C-H and C-C bond activation in propellanes.
- The study provides valuable insights into the factors governing bond activation in strained systems.
- Computational and experimental data offer a comprehensive understanding of propellane reactivity.
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