10.1021/om034385g
The study investigates the reactions of 3-(pentafluorophenyl)indene and (pentafluorophenyl)cyclopentadiene with tetrakis(dimethylamido)titanium(IV), resulting in the formation of products where one or both ortho fluorines of the C6F5 group are replaced by dimethylamino groups. This suggests a titanium-mediated, intramolecular nucleophilic aromatic substitution mechanism. The research led to the isolation of organic products and the conversion of substituted cyclopentadiene to a ferrocene derivative. The study provides insights into the selective activation of polyfluorinated organic compounds, a significant challenge in synthetic chemistry, and contributes to the understanding of transition metal complex mechanisms for C-F activation.
10.1016/j.jfluchem.2019.03.009
The research aims to explore and optimize reactions involving the selective activation and substitution of aromatic fluorine substituents in ortho-fluorinated anilines using Ti(NMe2)4 as a reagent. The study focuses on the regioselective defluoroamination reaction, where a fluorine atom vicinal to the NH2 group of the starting aniline is replaced with an NMe2 group, resulting in the formation of N,N-dimethyl-1,2-phenylenediamine derivatives. The conclusions drawn from the research indicate that the reactivity of these reactions increases with additional ring fluorination, generally following established regiochemical trends. Notably, compounds with fluorines in both the 2- and 6-positions can undergo substitution at both positions given extended reaction times. The chemicals used in this process include ortho-fluorinated anilines, Ti(NMe2)4, mesitylene as the solvent, and bis(4-fluorophenyl)ether as an internal NMR standard. The reactions were found to be general, reasonably efficient, and consistent with established ancillary-fluorine substituent effects, although preliminary experiments showed limited generalization to ortho-fluorinated phenols.
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