Redox-induced Diels–Alder revisited: impact of diene's oxidation on demanding cycloadditions

Jadwiszczak, Michał J.; Leszczyński, Piotr J.; Mazej, Zoran; Malinowski, Przemysław J.; Nawrocka, Ewa K.; Kazimierczuk, Krzysztof; Kwiatkowski, Piotr; Połczyński, Piotr; Grochowska-Tatarczak, Magdalena; Fijalkowski, Karol J.; Sadło, Jarosław; Grochala, Wojciech

doi:10.1039/d3qo00985h

Cited by 2 publications

(2 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 2a, we studied seven similar RPs of cycloaddition between anthracene and chalcone (1,3‐diphenylprop‐2‐en‐1‐one) derivatives 13 . As chalcone derivatives occur naturally in the environment, their backbone is present in various biologically active compounds, including approved drugs 20 …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Supporting the assignment of NMR spectra with variable‐temperature experiments

Nawrocka,

Jadwiszczak,

Leszczyński

et al. 2024

Magnetic Reson in Chemistry

Self Cite

View full text Add to dashboard Cite

Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful tools in analytical chemistry. An important step in the analysis of NMR data is the assignment of resonance frequencies to the corresponding atoms in the molecule being investigated. The traditional approach considers the spectrum's characteristic parameters: chemical shift values, internuclear couplings, and peak intensities. In this paper, we show how to support the process of assigning a series of spectra of similar organic compounds by using temperature coefficients, that is, the rates of change in chemical shift values associated with given changes in temperature.

show abstract

Section: Resultsmentioning

confidence: 99%

“…All (1–7) reaction products (RPs) 13 were dissolved in CDCl 3 and transferred to standard 5 mm NMR tubes. We acquired data using the Agilent 700 MHz DirectDrive2 NMR spectrometer equipped with a room temperature HCN probe at 22.3°C.…”

Section: Methodsmentioning

confidence: 99%

Supporting the assignment of NMR spectra with variable‐temperature experiments

Nawrocka,

Jadwiszczak,

Leszczyński

et al. 2024

Magnetic Reson in Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

Cobalt(II)‐Nitromethane Complex as an Efficient Catalyst Of Demanding Diels‐Alder Reactions on the Example of an Anthracene‐Chalcone System

Jadwiszczak,

Nawrocka,

Kwiatkowski

et al. 2024

ChemCatChem

View full text Add to dashboard Cite

Diels‐Alder (DA) cycloaddition of chalcones to anthracene and its 9‐substituted derivatives is an example of a demanding reaction that is not effective even under increased pressure. In this article we show good catalytic activity of an easily accessible complex cation [Co(CH3NO2)6]2+ stabilized by weakly coordinating anion [Al(OC(CF3)3)4]−. Our screening covering chalcone and anthracene derivatives with either activating or deactivating effects on reactivity in DA cycloadditions show that the catalyst allows to obtain [4+2] cycloadducts with yields up to 99% under mild conditions, even for 9‐bromoanthracene – a very poor diene in DA reactions. The reaction proceeds best in liquid SO2, which is an unusual solvent for this type of reaction. 9‐methylanthracene ‐ the most reactive diene among those tested in the study ‐ gives two regioisomeric cycloadducts and their ratio depends on the solvent used. Modelling of the reaction with DFT methods shows that Co(II) significantly lowers the activation energy of the cycloaddition. In the case of 9‐bromoanthracene the effect is much more pronounced than with e.g. recently reported redox‐activation of the diene, which is in agreement with much better yields obtained with the use of the cobalt catalyst.

show abstract

Redox-induced Diels–Alder revisited: impact of diene's oxidation on demanding cycloadditions

Abstract: The work presents the joint experimental and computational analysis of Diels-Alder (DA) reactions initiated by the one-electron oxidation of dienes: anthracene and buta-1,3-diene derivatives. The use of AgSO4 – a...

Cited by 2 publications

References 49 publications

Supporting the assignment of NMR spectra with variable‐temperature experiments

Supporting the assignment of NMR spectra with variable‐temperature experiments

Cobalt(II)‐Nitromethane Complex as an Efficient Catalyst Of Demanding Diels‐Alder Reactions on the Example of an Anthracene‐Chalcone System

Contact Info

Product

Resources

About