Tnfluoromethylation

Just as there is a marked difference m how methyl and tnfluoromethyl substituents affect the rate of electrophilic aromatic substitution so too there is a marked difference m how they affect its regioselectivity... [Pg.488]

Methyl group releases electrons stabilizes carbocation than than Tnfluoromethyl group withdraws electrons destabilizes carbocaUon... [Pg.492]

Electron releasing substituents attached to the ring have a negligible effect on the acidity of phenols Strongly electron withdrawing groups increase the acidity The compound 4 nitro 3 (tnfluoromethyl)phenol for example is 10 000 times more acidic than phenol... [Pg.1016]

BURTON Trilluoromelhylation Tnfluoromethylation of aryl iodides with Cd (Cu) reagents... [Pg.57]

Preparation of Tnfluoromethyl Ketones and Related Fluorinated Ketones Begue, J P, Bonnet-Dalpon, D Tetrahedron 47. 3207-3258 245 ... [Pg.21]

Recent Advances in Tnfluoromethylation (Jap) Uneyama, K Yuki Gosei Kagaku Kyokaishi 49 612-623 169... [Pg.22]

Tnfluoromethylations and Related Reactions in Organic Chemistry McClinton, D A Tetrahedron 48 6555-6666 228... [Pg.22]

With more electrophilic halogenated olefins, additions of tnfluoromethyl hypofluonte appear to go by radical processes [139] and give oligomeric products [140] or one-to-one adducts [141,142] (equation 4) depending on reaction conditions... [Pg.70]

Tnfluoromethyl- and perfluoro-/ert-butylhypofluorites also add to hexa-fluorobemene to give stable adducts [143] (equation 5)... [Pg.70]

Tnfluoromethyl hypofluonte will fluorinate Schiff bases, giving N,a,a-tn-fluoroatmnes and a-fluoroimines [144] and reacts with diazoketones to give adducts in modest yields [145] (equation 6) At-Substituted aziridines give nng opened products by 1,3 addition of fluonne on nitrogen and trifluoromethoxy on carbon [146] (equation 7)... [Pg.70]

Similarly complex is the fluorination of the Ihtes methylpyridines (a-, ()-, and 7-picolmes) with cesium tetrafluorocobaltate. 2-Methylpyridme was fluorinated at 270 °C for 180-200 mm, 3- and 4-methylpyridmes were fluorinated at 330 to 340 °C for 150 min All of them afforded the respective polyjluorinated pyridines and perfiuoro-1,2-, 1,3-dimethyl-, and 1-ethylpyrrolidine In addition, perfluoro-2-aza-2-hexene and bis(tnfluoromethyl)amine were isolated m variable yields [27] All the isolated products of the fluorination of 3-methylpyridme (3-picoline) are shown in equation 9. [Pg.125]

The addition of hydrogen fluoride to an aromatic isocyanide dichloride provides a route to the respective aryl-Af tnfluoromethyl amine [34] (equation 24)... [Pg.183]

Furan-2-carboxylic acid reacts with sulfur tetrafluoride at 0 °C to give 2-furoyl fluoride, but attempts at further fluorination results in resin formation [222] A second carboxylic group and/or electron withdrawing substiments, such as the nitro or tnfluoromethyl group, stabilize the furan ring Thus, turandicar-... [Pg.248]

Electrochemical reduction of carbon-fliionne bonds occurs at high pH when a carbonyl group is adjacent Polaiographic reduction of a a,a-tnfluoroacetophe-none without loss of fluonne predominates in acidic media to give the alcohol and the corresponding pinacol, whereas reduction of the unprotonated ketone results in hydrogenolysis of the tnfluoromethyl group to form acetophenone as product Il] (equation 8)... [Pg.298]

In teirakis(tnfluoromethyl)aZ/eMe, potassium permanganate hydroxylates one double bond [44], the resultmg enol tautomenzes to an a-hydroxykewne (equation 37). [Pg.333]

A detailed study ot the oxidation of ortho-, meta-, and para-tnfluoromethyl phenols showed that oxidation with chloric acid at 5 to 10 C for 0 5 h gives a complex mixmre of products [59] with isolable 2-chloro-1 hydroxy-2-tnfluoro-methylcyclopent-4-en-3-one-1 -carboxylic acid... [Pg.339]

Aliphatic Ct, (A-dietus, activated with ester groups at both terminal positions, undergo tnfluoromethylation with cyclization durmg electrochemical oxidation with sodium tnfluoroacetate [79] (equation 70). [Pg.346]

The conversion of cyclic sulfides to sulfones is accompbshed by more energetic oxidations. Perhalogenated thiolanes [106] and 1,3-dithietanes [107] are oxidized to sulfones and disulfones, respectively, by a mixture of chromium trioxide and nitric acid (equation 98) The same reagent converts 2,4-dichloro-2,4-bis(tnfluoromethyl)-l,3-dif/u cto cs to disulfone derivatives [107], whereas trifluoromethaneperoxysulfonic acid converts the starting compound to a sul-fone-sulfoxide derivative [2(equation 99). [Pg.355]

Analogous reactions under free-radical conditions show a preference for the erythro isomer when X = Cl, however when X = tnfluoromethyl, the reaction shows essentially no stereoselectivity [S] (Table 3)... [Pg.366]

If the benzotrifluoride contains an ammo group N-nitration in acenc acid and acetic anhydride furnishes the tnfluoromethyl nitroaminobenzene [22] C-nitration... [Pg.392]

Hydrolysis of A-substituted tnfluoromethyl fluoroformamides leads to A-sub-sdtuted trifluoromethylamines by loss of hydrogen fluonde and carbon dioxide [55] (equation 55). [Pg.439]

The electron-withdrawing power of the tnfluoromethyl group in the 2,2,2-tri-fluoroethyl ether of 9-hydroxy-9-(dinitromethyl)fluorene considerably retards its hydrolysis compared with simple alkyl ethers [59] (equation 57)... [Pg.440]

On the contrary, tnfluoromethyl groups severely impede Sj l or reactions when located a to the reaction site. However, aminolysis of l-phenyl-2,2,2,-tri-fluoroethyl tosylate [Sd] and tnfluoroethyl chloride [ST] and its corresponding nonaflate [SS] can be performed under severe conditions (equation 76). [Pg.465]

The condensation of 6 methoxy-1-vinyl-l-tetralol with 2-ttifluoromethyl-l 3 cyclopentanedione in the presence of a small amount of triethylamine produces a secodione (equation 104) This dione is an intermediate in the total synthesis of 13-tnfluoromethyl estrogens, such as 18,18,18-tnfluoro 17(3 estradiol [121] Regwselecnve alkylation of a fluorinated (3-disulfone occurs at low tempera ture [122] (equation 105)... [Pg.473]

Tnfluoromethylation of double bonds or of aromatic nuclei is performed by bis(trifluorotnethyl) tellurium [145] (equation 125)... [Pg.480]

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 presence of a tnalkylsUyl group in a fluonnated organic compound may be useful to direct further transformations of that matenal Yet m some instances it IS the fluonnated substituent that controls the reactions of the tnalkylsdyl group Contrary to predictions, treatment of tert-hnlyX 3-tnfluoromethyl-6-tnmethylsilyl-phenyl carbamate with rert-butyllithium results m metallation of one of the methyl groups attached to silicon rather than that of the aromatic nng [90] (equation 75)... [Pg.599]

Lastly, a-trimetfayisflyl enolates have been added to trifluoromethyl ketones to effect Peterson olefination of the tnfluoromethyl ketones [IS (equation 13)... [Pg.621]

When ethyl trifluoroacetylacetate is treated with an allylic alkoxide, tran-sesterification is followed by ester enolate Claisen rearrangement m a process that on decarboxylation yields stereospecifically the tnfluoromethyl ketone product [22] (equation 19)... [Pg.626]

However, bis(tnfluoromethyl)cadmium gives CF3NO with tnmethyltm nitrate [5] (equation 4)... [Pg.671]

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