Mechanistic investigation of the isomerization of 5-vinyl-2-norbornene.

Department of Chemistry, Kyung Hee University, 1 Hoegi-dong, Dondaemoon-gu, Seoul 130-701, Korea.
The Journal of Organic Chemistry (Impact Factor: 4.56). 02/2006; 71(3):911-4. DOI: 10.1021/jo0518203
Source: PubMed

ABSTRACT The isomerization reaction of 5-vinyl-2-norbornene (VNB) to 5-ethylidene-2-norbornene (ENB) has been performed using a catalytic system consisting of an alkali metal hydride and an amine. Among various amines tested, only aliphatic 1,2-diamines exhibited the activity for the isomerization. The isomerization was also affected by the alkali metal hydride employed. The activity of the alkali metal hydride increased with the increasing size of alkali metal: KH > NaH > LiH. A series of electron paramagnetic resonance (EPR) and UV-vis experiments on the active species suggest that the isomerization of VNB proceeds through a radical mechanism.

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