Insight into the factors controlling the equilibrium of allylic azides

Vallejos, Margarita; Labadié, Guillermo R.

doi:10.1039/c9ra10093h

Cited by 11 publications

(6 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following azide displacement DBU was added directly, which gave 10 and 11 , following purification, in 74 % and 65 % yields respectively. In addition, identical stereoselectivity to the two‐step approach was observed demonstrating that the change of solvent from chloroform to acetonitrile is inconsequential (Scheme ) . The stereochemical outcome observed in the reactions forming 10 and 11 were not, in the light of previous work, completely unanticipated and Inomata has reviewed this type of vinyl to allyl sulfone isomerisation reaction, presenting a detailed discussion of the mechanistic subtleties involved in this process .…”

Section: Resultsmentioning

confidence: 94%

“…Thereafter, straightforward bromide displacement gave γ‐azido‐α,β‐unsaturated sulfones 8 and 9 . These compounds proved relatively unstable, generating a material that was insoluble in both typical organic solvents and water, consequently the chemical yields for the isolation of 8 and 9 were variable . However, treatment of the crude material directly after aqueous work‐up with DBU (1 equiv.)…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Isomerisation of Vinyl Sulfones for the Stereoselective Synthesis of Vinyl Azides

et al. 2020

View full text Add to dashboard Cite

Reported is the construction, and facile base-mediated conversation of ten differently substituted 3-azido E-vinyl sulfones (γ-azido-α,-unsaturated sulfones) into their isomeric vinyl azide counterparts. The requisite 3-azido E-vinyl sulfones were prepared from 3-bromo E-vinyl sulfones, which in turn were accessed from allyl sulfones via a bromination-elimination sequence. In relation to this a one-pot azidation-isomerisation sequence was developed which enabled the direct formation of the vinyl azides from the corresponding 3-bromo E-vinyl sulfones. Similarly, a convenient one-pot Horner-Wadsworth-Emmons olefination-isomerisation approach was utilised in or-[a] N.

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Isomerisation of Vinyl Sulfones for the Stereoselective Synthesis of Vinyl Azides

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The data for the TS 1−2 i did not follow the correlation observed, due to its primary azide structure that had a greater stability compared to the secondary azides. 61 It is important to consider these relationships for reagents with similar structures.…”

Section: ■ Computational Methodsmentioning

confidence: 99%

Understanding the Fate of the Banert Cascade of Propargylic Azides: Sigmatropic versus Prototropic Pathway

Villarreal-Parra,

Di Gresia,

Labadie

et al. 2023

J. Org. Chem.

Self Cite

View full text Add to dashboard Cite

The Banert cascade is an efficient synthetic strategy for obtaining 4,5-disubstituted 1,2,3-triazoles. The reaction can proceed via a sigmatropic or prototropic mechanism depending on the substrate and the conditions. In this work, the mechanisms of both pathways from propargylic azides with different electronic features were investigated using density functional theory, quantum theory of atoms in molecules, and natural bond orbital approaches. The calculated energy barriers were consistent with the experimental data. Three patterns of electron density distribution on the transition structures were observed, which reflected the behaviors of the reactants in the Banert cascade. The stronger conjugative effects were associated with lower/higher free activation energies of sigmatropic/prototropic reactions, respectively. A clear relationship between the accumulation of the charge at the C3 atom of propargylic azides with the energy barriers for prototropic reactions was found. Thus, the obtained results would allow the prediction of the reaction’s course by evaluating reactants.

show abstract

“…The data for the TS1-2i did not conform to the correlation, due to its primary azide structure which had a greater stability compared to the secondary azides. 58 Therefore, it is suggested to take these relationships into account for the reagents with similar structures.…”

Section: Topological Charge Density Analysis On Transition Structuresmentioning

confidence: 99%

Understanding the Fate of the Banert Cascade of Propargylic Azides. Sigmatropic versus Prototropic Pathway

Villareal-Parra

Gresia

Labadié

et al. 2023

Preprint

View full text Add to dashboard Cite

The Banert cascade is an efficient synthetic strategy for obtaining 4,5-disubstituted 1,2,3-triazoles. The reaction can proceed via a sigmatropic or prototropic mechanism depending on the substrate and the conditions. In this work, the mechanism of both pathways from propargylic azides with different electronic features were investigated using DFT, QTAIM and NBO approaches. The calculated energies barriers were consistent with the experimental data. Three patterns of electron density distribution on the transition structures were observed, which reflected the behaviours of the reactants in the Banert cascade. The stronger conjugative effects were associated with lower/higher free activation energies of sigmatropic/prototropic reactions, respectively. A clear relationship between the accumulation of the charge at the C3 atom of propargylic azides with the energy barriers for prototropic reactions was found. Thus, the obtained results would allow the prediction of the reactions course evaluating reactants.

show abstract

Insight into the factors controlling the equilibrium of allylic azides

Abstract: The factors controlling the allyl azides equilibrium has been studied by different theoretical approaches setting the basis to predict the regioisomers predominance in the equilibrium mixture.

Cited by 11 publications

References 44 publications

Isomerisation of Vinyl Sulfones for the Stereoselective Synthesis of Vinyl Azides

Isomerisation of Vinyl Sulfones for the Stereoselective Synthesis of Vinyl Azides

Understanding the Fate of the Banert Cascade of Propargylic Azides: Sigmatropic versus Prototropic Pathway

Understanding the Fate of the Banert Cascade of Propargylic Azides. Sigmatropic versus Prototropic Pathway

Contact Info

Product

Resources

About