23847-64-5Relevant academic research and scientific papers
Iron-catalyzed stereospecific activation of olefinic C-H bonds with grignard reagent for synthesis of substituted olefins
Ilies, Laurean,Asako, Sobi,Nakamura, Eiichi
supporting information; experimental part, p. 7672 - 7675 (2011/06/26)
The reaction of an aryl Grignard reagent with a cyclic or acyclic olefin possessing a directing group such as pyridine or imine results in the stereospecific substitution of the olefinic C-H bond syn to the directing group. The reaction takes place smoothly and without isomerization of the product olefin in the presence of a mild oxidant (1,2-dichloro-2-methylpropane) and an aromatic cosolvent. Several lines of evidence suggest that the reaction proceeds via iron-catalyzed olefinic C-H bond activation rather than an oxidative Mizoroki-Heck-type reaction.
Excited State Reactivity of Aza Aromatics. 9. Fluorescence and Photoisomerization of Planar and Hindered Styrylpyridines
Bartocci, G.,Mazzucato, U.,Masetti, F.,Galiazzo, G.
, p. 847 - 851 (2007/10/02)
The effect of methyl substitution at the ethylenic bridge on the fluorescence and trans -> cis photoisomerization of styrylpyridines (StP's) has been investigated.As compared with the unsubstituted planar olefins, steric hindrance modifies the shape of the potential energy barrier for photoisomerization.The hindered compounds show a marked decrease in the fluorescence quantum yield.A parallel decrease in the photoreaction quantum yield has been observed for the α-methyl derivatives of stilbene and 3-StP.Temperature and solvent effects on planar and hindered StP's give interesting information on the intramolecular rotation in excited azastilbenes and its competition with the other deactivation pathways.While intersystem crossing is negligible in fluid solvent, it becomes competitive with fluorescence in high viscosity media.The photoisomerization mechanism is discussed on the basis of the model available for stilbene.
