6533b872fe1ef96bd12d2d8f
RESEARCH PRODUCT
On the ionizing properties of supercritical carbon dioxide: uncatalyzed electrophilic bromination of aromatics
Javier Reig-lópezMaría Elena González NúñezThais Delgado-abadGregorio AsensioJaime Martínez-ferrerRossella MelloRafael Aceretesubject
Solventchemistry.chemical_compoundAqueous solutionSupercritical carbon dioxidechemistryHydrogen bondGeneral Chemical EngineeringCarbon dioxideElectrophileHalogenationIonic bondingGeneral ChemistryPhotochemistrydescription
Supercritical carbon dioxide (scCO2), a solvent with a zero dipole moment, low dielectric constant, and no hydrogen bonding behavior, is a suitable medium to perform the uncatalyzed electrophilic bromination of weakly activated aromatics with no interference of radical pathways. The ability of scCO2 to promote these reactions matches those of strongly ionizing solvents such as aqueous acetic and trifluoroacetic acids. Conversely, carbon tetrachloride, with similar polarity parameters to scCO2, leads exclusively to side chain functionalization. The strong quadrupole moment, and the acidic, but non basic, Lewis character of carbon dioxide, are proposed as key factors for the singular performance of scCO2 in reactions involving highly polar and ionic intermediates.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-01-01 | RSC Adv. |