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Kinetic studies of inverse electron demand Diels-Alder reactions (iEDDA) of norbornenes and 3,6-dipyridin-2-yl-1,2,4,5-tetrazine.

Knall AC, Hollauf M, Slugovc C - Tetrahedron Lett. (2014)

Bottom Line: Norbornenes are, due to their straightforward synthetic availability, especially interesting in the latter context.Therefore, the reactivity of different norbornene-based compounds was compared with unsubstituted norbornene and other alkenes using UV-vis measurements for the determination of reaction rates under pseudo first order conditions.Thereby, exo,exo-5-norbornene-2,3-dimethanol was found to be almost as reactive as unsubstituted norbornene whereas (±)-endo,exo-dimethyl-5-norbornene-2,3-dicarboxylate reacted only insignificanty faster than unstrained alkenes.

View Article: PubMed Central - PubMed

Affiliation: Institute for Chemistry and Technology of Materials (ICTM), Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria.

ABSTRACT
Inverse electron demand Diels-Alder additions (iEDDA) between 1,2,4,5-tetrazines and olefins have recently found widespread application as a novel 'click chemistry' scheme and as a mild technique for the modification of materials. Norbornenes are, due to their straightforward synthetic availability, especially interesting in the latter context. Therefore, the reactivity of different norbornene-based compounds was compared with unsubstituted norbornene and other alkenes using UV-vis measurements for the determination of reaction rates under pseudo first order conditions. Thereby, exo,exo-5-norbornene-2,3-dimethanol was found to be almost as reactive as unsubstituted norbornene whereas (±)-endo,exo-dimethyl-5-norbornene-2,3-dicarboxylate reacted only insignificanty faster than unstrained alkenes.

No MeSH data available.


Related in: MedlinePlus

UV-vis absorption spectrum of 3,6-dipyridin-2-yl-1,2,4,5-tetrazine (pyTz).
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f0005: UV-vis absorption spectrum of 3,6-dipyridin-2-yl-1,2,4,5-tetrazine (pyTz).

Mentions: The UV-vis absorption spectrum of pyTz shows two characteristic maxima, a stronger one at around 350 nm [ε1 = 30400 L mol−1 cm−1] and a weaker absorption maximum at around 550 nm [ε2 = 400 L mol−1 cm−1], which is responsible for the pink colour of the compound (Fig. 1). Since we observed that some of the formed pyridazines appeared yellowish, we decided to use the weaker absorption maximum to avoid interference with potentially absorbing products.


Kinetic studies of inverse electron demand Diels-Alder reactions (iEDDA) of norbornenes and 3,6-dipyridin-2-yl-1,2,4,5-tetrazine.

Knall AC, Hollauf M, Slugovc C - Tetrahedron Lett. (2014)

UV-vis absorption spectrum of 3,6-dipyridin-2-yl-1,2,4,5-tetrazine (pyTz).
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4125744&req=5

f0005: UV-vis absorption spectrum of 3,6-dipyridin-2-yl-1,2,4,5-tetrazine (pyTz).
Mentions: The UV-vis absorption spectrum of pyTz shows two characteristic maxima, a stronger one at around 350 nm [ε1 = 30400 L mol−1 cm−1] and a weaker absorption maximum at around 550 nm [ε2 = 400 L mol−1 cm−1], which is responsible for the pink colour of the compound (Fig. 1). Since we observed that some of the formed pyridazines appeared yellowish, we decided to use the weaker absorption maximum to avoid interference with potentially absorbing products.

Bottom Line: Norbornenes are, due to their straightforward synthetic availability, especially interesting in the latter context.Therefore, the reactivity of different norbornene-based compounds was compared with unsubstituted norbornene and other alkenes using UV-vis measurements for the determination of reaction rates under pseudo first order conditions.Thereby, exo,exo-5-norbornene-2,3-dimethanol was found to be almost as reactive as unsubstituted norbornene whereas (±)-endo,exo-dimethyl-5-norbornene-2,3-dicarboxylate reacted only insignificanty faster than unstrained alkenes.

View Article: PubMed Central - PubMed

Affiliation: Institute for Chemistry and Technology of Materials (ICTM), Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria.

ABSTRACT
Inverse electron demand Diels-Alder additions (iEDDA) between 1,2,4,5-tetrazines and olefins have recently found widespread application as a novel 'click chemistry' scheme and as a mild technique for the modification of materials. Norbornenes are, due to their straightforward synthetic availability, especially interesting in the latter context. Therefore, the reactivity of different norbornene-based compounds was compared with unsubstituted norbornene and other alkenes using UV-vis measurements for the determination of reaction rates under pseudo first order conditions. Thereby, exo,exo-5-norbornene-2,3-dimethanol was found to be almost as reactive as unsubstituted norbornene whereas (±)-endo,exo-dimethyl-5-norbornene-2,3-dicarboxylate reacted only insignificanty faster than unstrained alkenes.

No MeSH data available.


Related in: MedlinePlus