Ozonolysis

Zvilichovsky, Gury; Zvilichovsky, B.

doi:10.1002/9780470772515.ch13

Cited by 11 publications

(6 citation statements)

References 301 publications

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“…The reaction of carbonyls with hydrogen peroxide is a black box that hides a surprising amount of complexity. Remarkably, this single type of peroxide-forming process opens access to various classes of peroxides, such as alkylperoxides, geminal bis-peroxides, 1,2-dioxolanes, 1,2,4-trioxolanes, ,, 1,2,4-trioxanes, 1,2,4,5-tetraoxanes, and tricyclic monoperoxides …”

Section: Introductionmentioning

confidence: 99%

How to Build Rigid Oxygen-Rich Tricyclic Heterocycles from Triketones and Hydrogen Peroxide: Control of Dynamic Covalent Chemistry with Inverse α-Effect

et al. 2020

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We describe an efficient one-pot procedure that “folds” acyclic triketones into structurally complex, pharmaceutically relevant tricyclic systems that combine high oxygen content with unusual stability. In particular, β,γ′-triketones are converted into three-dimensional polycyclic peroxides in the presence of H2O2 under acid catalysis. These transformations are fueled by stereoelectronic frustration of H2O2, the parent peroxide, where the lone pairs of oxygen are not involved in strongly stabilizing orbital interactions. Computational analysis reveals how this frustration is relieved in the tricyclic peroxide products, where strongly stabilizing anomeric n O→σC–O * interactions are activated. The calculated potential energy surfaces for these transformations combine labile, dynamically formed cationic species with deeply stabilized intermediate structures that correspond to the introduction of one, two, or three peroxide moieties. Paradoxically, as the thermodynamic stability of the peroxide products increases along this reaction cascade, the kinetic barriers for their formation increase as well. This feature of the reaction potential energy surface, which allows separation of mono- and bis-peroxide tricyclic products, also explains why formation of the most stable tris-peroxide is the least kinetically viable and is not observed experimentally. Such unique behavior can be explained through the “inverse α-effect”, a new stereoelectronic phenomenon with many conceptual implications for the development of organic functional group chemistry.

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Section: Introductionmentioning

confidence: 99%

How to Build Rigid Oxygen-Rich Tricyclic Heterocycles from Triketones and Hydrogen Peroxide: Control of Dynamic Covalent Chemistry with Inverse α-Effect

et al. 2020

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“…The mechanism of ozonolysis of olefins is of continuing interest because of the importance of this reaction in synthesis and in atmospheric chemistry. , The mechanism, introduced by Criegee , to explain the ozonolysis reaction (Figure ), stood the test of time in a remarkable way: two proposed intermediates, the primary and secondary ozonides (POZ and SOZ, respectively), were isolated and completely characterized. However, in spite of considerable efforts, the species intermediate between them was never observed in practice.…”

Section: Introductionmentioning

confidence: 99%

“…Only indirect proofs of the presence of CO are available. In hydroxylic solvents, the formation of hydroperoxides was explained as due to a reaction between a CO and an alcohol; , in nonpolar solvents, CO's were trapped by activated alkenes 1 Criegee mechanism. …”

Section: Introductionmentioning

confidence: 99%

Theoretical Analysis of the Stereoselectivity in the Ozonolysis of Olefins. Evidence for a Modified Criegee Mechanism

Ponec¹,

Yuzhakov²,

Haas³

et al. 1997

J. Org. Chem.

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The Criegee mechanism of the ozonolysis of cis and trans symmetric alkenes of the type RCH=CHR is investigated by semiempirical AM1 calculations. The observed stereoselectivity trends are qualitatively explained in terms of the original Criegee mechanism. However, it is shown that in order to elucidate some subtle stereochemical effects as well as to account for the vain attempts to detect the carbonyloxide intermediate, a modification is required. This is done by adopting a proposal made by Cremer et al. (Chem. Phys. Lett. 1991, 187, 491) for the specific case of ethylene and applying it to all systems. The carbonyl oxide and aldehyde formed upon dissociation of the primary ozonide are not separated but form a strongly bound complex that subsequently transforms to the secondary ozonide.

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“…However, peroxides containing the 1,2,4-trioxolane moiety (i.e., secondary ozonides) have been traditionally obtained using ozone. Numerous papers reported the synthesis of ozonides via the reaction of ozone with alkenes . The first example of ozonolysis of ethylene goes back to 1855 .…”

Section: Introductionmentioning

confidence: 99%

Ozone-Free Synthesis of Ozonides: Assembling Bicyclic Structures from 1,5-Diketones and Hydrogen Peroxide

et al. 2018

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Reactions of 1,5-diketones with HO open an ozone-free approach to ozonides. Bridged ozonides are formed readily at room temperature in the presence of strong Brønsted or Lewis acids such as HSO, p-TsOH, HBF, or BF·EtO. The expected bridged tetraoxanes, the products of double HO addition, were not detected. This procedure is readily scalable to produce gram quantities of the ozonides. Bridged ozonides are stable and can be useful as building blocks for bioconjugation and further synthetic transformations. Although less stabilized by anomeric interactions than bis-peroxides, ozonides have an intrinsic advantage of having only one weak O-O bond. The role of the synergetic framework of anomeric effects in bis-peroxides is to overcome this intrinsic disadvantage. As the computational data have shown, this is only possible when all anomeric effects in bis-peroxides are activated to their fullest degree. Consequently, the cyclization selectivity is determined by the length of the bridge between the two carbonyl groups of the diketone. The generally large thermodynamic preference for the formation of cyclic bis-peroxides disappears when 1,5-diketones are used as the bis-cyclization precursors. Stereoelectronic analysis suggests that the reason for the bis-peroxide absence is the selective deactivation of anomeric effects in a [3.2.2]tetraoxanonane skeleton by a structural distortion imposed on the tetraoxacyclohexane subunit by the three-carbon bridge.

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Ozonolysis

Cited by 11 publications

References 301 publications

How to Build Rigid Oxygen-Rich Tricyclic Heterocycles from Triketones and Hydrogen Peroxide: Control of Dynamic Covalent Chemistry with Inverse α-Effect

How to Build Rigid Oxygen-Rich Tricyclic Heterocycles from Triketones and Hydrogen Peroxide: Control of Dynamic Covalent Chemistry with Inverse α-Effect

Theoretical Analysis of the Stereoselectivity in the Ozonolysis of Olefins. Evidence for a Modified Criegee Mechanism

Ozone-Free Synthesis of Ozonides: Assembling Bicyclic Structures from 1,5-Diketones and Hydrogen Peroxide

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