Sonochemical switching from ionic to radical pathways in the reactions of styrene and trans-β-Methylstyrene with lead tetraacetate

Sonoprocess of Ceramic Materials

“…At higher intensity, however, it was found that a pseudo-boehmite phase with lower crystallinity (i.e., poorly detected by X-ray diffractometry) was precipitated. This may be called sonochemical switching [12] from bayerite to pseudo-boehmite according to ultrasonic intensity. We may remember in general that a less-defined structure/phase is likely to form with an intensive sonication.…”

What Is Sonochemistry?

“…Ando et al found for the case of solideliquid two-phase reactions that under stirring conditions, acetylation between benzyl bromide and toluene in an anhydrous solvent proceeds in the form of a FriedeleCrafts reaction, whereas under ultrasonic irradiation, the aromatic electrophilic substitution of benzyl bromide and cyanides in aromatic solvents changes to a nucleophilic one. Kitazume and Ishikawa [34], Ando et al [33], Makino et al [35], and Suga et al [36] contributed to the series. They concluded that radical reactions effectively proceed under ultrasonic irradiation when ionic reactions coexist with radical ones in a conventional reaction system.…”

“…This research can be seen as pioneering work in the study of sonochemistry for the purposes of organic synthesis. This change in reaction path due to ultrasonic irradiation of the reaction system was termed "sonochemical switching" [33]. In other words, the reaction pathway switches under ultrasonic irradiation [32].…”

Jean-Louis Luche and the Interpretation of Sonochemical Reaction Mechanisms

“…A further example of switching is to be found in another paper from the Ando group describing the reaction of lead tetraacetate with styrene [ 29 ]. The addition may follow either an ionic or a radical pathway, affording the products depicted in Scheme 3 .…”