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Fluonne aromatics

Vanadium pentafluoride replaces benzylic hydrogen by fluonne but also adds fluonne to the aromatic system, giving fluonnated cyclohexadienes and cyclohexenes [5] (equation 5)... [Pg.120]

The replacement of a substituent on an aromauc nng by a nucleophile is termed arylaUon. This chapter considers the replacement by nucleophihc oxygen, sulfur, nitrogen, and carbon of aromatic fluonne atoms, which are often activated by electron-withdrawing groups. [Pg.501]

Perfluoropyridine gives the usual replacement of the 4-fluonne on reactions with either aromatic or aliphatic mercaptides [55, 36] The reaction of perfluoropyridine with cesium tnfluoromethyl mercaptide, generated from thiocarbonyl fluoride and cesium fluonde, shows temperature dependence of selectivity in fluonne displacement [55 36] (equation 24)... [Pg.508]

The replacement of reactive aromatic fluonne by nitrogen nucleophiles is a well-known process for the preparation of aromatic amines The aromatic fluonne IS activated by the presence of electron-withdrawing substituents on the aromatic ring, especially in ortho and para positions [57 38, 39] (equations 25-27)... [Pg.508]

An unactivated aryl fluorine may be activated by complexauon with chro-mium(VI). Replacement of the fluonne in the complexed system occurs readily, and the uncomplexetl aromatic product can be generated by treatment with iodine [84] (equation 46)... [Pg.515]

The mfluoromethyl group activates the fluorine in position 4 ofperfluorotolu ene toward reaction with carbon nucleophiles Examples on che use of perfluoro-toluene as an arylation agent abound, and in all cases, the 4-fluonne atom is replaced predommantly or exclusively [% 87,88,89, 90 (equation 48) In perjluoromesity-lene, the aromatic fluorine atoms are activated toward Ar reaction, and a reaction... [Pg.516]

Although the early reacbons of perfluoroaliphatic and aromatic lithium compounds with various carbonyl compounds gave low yields and mixtures of prod ucts, the current understanding of experimental conditions makes this reaction an attractive means of preparing a variety of fluonne-containmg compounds... [Pg.666]

Fluonne-Contaming Aromatic Ammo Acids (Russ) Kukhar, V P, Yagupol skn, Y L, Gems, I 1, Kolycheva, M T Usp Khim. 60. 2047-2063 100... [Pg.22]

Fluonne atoms in aromatic nitrogen heterocycles are readily replaced by oxygen nucleophiles [77] Bistnfluoromethyl hydroxylarmne anion is an interesting nucleophde for the introduction of oxygen into perfluoropyndine Rearrangement of the product occurs at 125 °C [18 (equation 12)... [Pg.503]

The effect of monofluorination on alkene or aromatic reactivity toward electrophiles is more difficult to predict Although a-fluonne stabilizes a carbocation relative to hydrogen, its opposing inductive effect makes olefins and aromatics more electron deficient. Fluorine therefore is activating only for electrophilic reactions with very late transition states where its resonance stabilization is maximized The faster rate of addition of trifluoroacetic acid and sulfuric acid to 2-fluoropropene vs propene is an example [775,116], but cases of such enhanced fluoroalkene reactivity in solution are quite rare [127] By contrast, there are many examples where the ortho-para-dueeting fluorine substituent is also activating in electrophilic aromatic substitutions [128]... [Pg.995]

Methods of Introduction of Fluonne into Aromatic and Nitrogen-Contaimng Heterocyclic Compounds (Czech) Hradil,P,Radl,S Chem Listy S4, 952-969 m ... [Pg.21]


See other pages where Fluonne aromatics is mentioned: [Pg.510]    [Pg.995]    [Pg.1041]    [Pg.510]   
See also in sourсe #XX -- [ Pg.43 , Pg.44 ]




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Electron withdrawing groups aromatic fluonne by nucleophiles

Fluonne

In replacement of aromatic fluonne

Mechanism in replacement aromatic fluonne

Nitrite, replacement of aromatic fluonne

Replacement of aromatic fluonne

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