Nucleophilic Substitution of Nitro Group in 3,5-Dinitrobenzotrifluoride
In the reaction of 3,5-dinitrobenzotrifluoride with phenols and thiophenol in the presence of potassium carbonate, fluoride- and nitrite-ions in DMF at 25-145°C, substitution of a nitro group takes place with formation of the corresponding 3-nitro-5-R-benzotrifluorides.
Khalfina,Rogozhnikova,Vlasov
p. 1325 - 1331
(2007/10/03)
THE TRIFLUOROMETHYLATION OF CHLOROAROMATICS USING THE COPPER-CF2Br2-DIALKYLAMIDE REACTION SYSTEM
The in situ generation of CuCF3 from the reaction of copper, dibromodifluoromethane and either N,N-dimethylformamide or N,N-dimethylacetamide (Burton's reagent) has been used for the direct substitution of chlorine by CF3 in a number of aromatic substrates.Particular attention has been paid to the effects of ring substituents on the efficiency of reaction.
Clark, James H.,Denness, James E.,McClinton, Martin A.,Wynd, Andrew J.
p. 411 - 426
(2007/10/02)
The Direct Trifluoromethylation of Aryl Chlorides using Burton's Reagent
The copper-dibromodifluoromethane-N,N-dimethylacetamide reaction system trifluoromethylates electronically activated aryl chlorides possessing ortho groups capable of interacting with the metal.
Clark, James H.,McClinton, Martin A.,Blade, Robert J.
p. 638 - 639
(2007/10/02)
Comparisons of Rate and Equilibrium Data for Reactions of Sulphite Ions at Substituted and Unsubstituted Ring-Positions in 1-X-3,5-Dinitrobenzenes and 1-X-4-Chloro-3,5-Dinitrobenzenes (X = NO2, CO2Me, CF3). The Effects of a Chloro-Substituent on Ipso-Substitution.
Reaction of 1-X-3,5-dinitrobenzenes (1) with sulphite ions yields isomeric adducts formed by attack at the 2- or 4-positions.Reaction of 1-X-4-chloro-3,5-dinitrobenzenes (4) results in adduct formation by attack at the 2-position and in substitution of the chloro-substituent.Kinetic and equilibrium data in DMSO-water mixtures are reported for these processes.The presence in (4) of the chlorine atom results in a general reduction in the rate of nucleophilic attack, the effect being particularly large for ipso-reaction (attack at the 4-position).The relative positional reactivities are reported and are compared with those for the corresponding reactions with hydroxide ions.
Crampton, Michael R.,Greenhalgh, Colin,Machell, Gavin,Williams, David P. E.