bromides from the corresponding 1,1-diarylethylenes. This protocol not only provides a convenient and straightforward strategy for the rapid construction of various 2,2-diarylvinyl bromides without bromine and extra oxidants, but also can improve the atom economy of Kornblum oxidative reaction.
A general and direct electrochemicaldimethoxylation of olefins is reported, which enables a divergent route to different products depending on the structure of olefins. The present protocol features mild conditions and broad substrate scope (49 examples) obviating the usage of transtion‐metals and external oxidants. More importantly, to rationalize the divergent route of the transformation, an ionic‐like
An efficient metal-free MizorokiâHeck type reaction of di- and tri-substituted alkenes with 2-chloro-dithiane has been developed under ambient pressure of air or using a relatively low loading of BF3·Et2O. This study represents a new environmentally friendly method for the syntheses of dithianyl-substituted alkene derivatives via a radical oxidative coupling process.
Arylcyclopropane photochemistry. Substituent effects on the photochemical conversion of 1,1-diarylcyclopropanes to 1,1-diarylpropenes and 1-arylindanes.
作者:Stephen S. Hixson、Lothar A. Franke
DOI:10.1016/s0040-4039(00)81321-0
日期:1983.1
The rate of photochemical rearrangement of 1,1-diarylcyclopropanes to 1,1-diarylpropenes and 1-arylindanes is enhanced by electron-withdrawing groups on the aromatic rings and diminished by electron-donating groups.
Introduction of a substituent into ortho-position of β-aryl group in a vinyl bromide resulted in the preferential formation of a vinyl cation in the photolysis. It is considered that the steric repulsion of β-aryl groups makes a convenient conformation for an electron transfer from the aromatic ring to the halogen atom in the radical pair.