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Radical fluorination is a type of fluorination reaction, complementary to nucleophilic and electrophilic approaches. [1] It involves the reaction of an independently generated carbon-centered radical with an atomic fluorine source and yields an organofluorine compound .
The direct fluorination of hydrocarbons with F 2, often diluted with N 2, is useful for highly fluorinated compounds: R 3 CH + F 2 → R 3 CF + HF. Such reactions however are often unselective and require care because hydrocarbons can uncontrollably "burn" in F 2, analogous to the combustion of hydrocarbon in O 2. For this reason, alternative ...
Reductive fluorination: 2 CrO 2 F 2 + XeF 2 → 2 CrOF 3 + Xe +O 2. Aromatic fluorination: Alkene fluorination: Radical fluorination in radical decarboxylative fluorination reactions, [10] in Hunsdiecker-type reactions where xenon difluoride is used to generate the radical intermediate as well as the fluorine transfer source, [28] and in ...
Trifluoromethyl hypofluorite is an organofluorine compound with the chemical formula C F 3 OF.It exists as a colorless gas at room temperature and is highly toxic. [1] It is a rare example of a hypofluorite (compound with an O−F bond).
Electrophilic fluorinating reagents could in principle operate by electron transfer pathways or an S N 2 attack at fluorine. This distinction has not been decided. [2] By using a charge-spin separated probe, [3] it was possible to show that the electrophilic fluorination of stilbenes with Selectfluor proceeds through an SET/fluorine atom transfer mechanism.
The relative rates at which different halogens react vary considerably: [citation needed] fluorine (108) > chlorine (1) > bromine (7 × 10 −11) > iodine (2 × 10 −22).. Radical fluorination with the pure element is difficult to control and highly exothermic; care must be taken to prevent an explosion or a runaway reaction.
In reductive hydrodefluorination the fluorocarbon is reduced in a series of single electron transfer steps through the radical anion, the radical and the anion with ultimate loss of a fluorine anion. An example is the conversion of pentafluorobenzoic acid to 3,4,5-tetrafluorobenzoic acid in a reaction of zinc dust in aqueous ammonia.
Consider acetic acid and its mono-, di-, and trifluoroacetic derivatives and their pK a values (4.74, 2.66, 1.24, and 0.23 [note 2]); [28] in other words, the trifluoro derative is 33,800 times stronger an acid than acetic. [29] Fluorine is a principal component of the strongest known charge-neutral acid, fluoroantimonic acid (H 2 FSbF 6). [30]