Phosphinodefluorination of polyfluorobenzenes by silylphosphines Ph(R)PSiMe3 (R=Me, Ph): Further experimental and computational evidences for the concerted ANDN mechanism of aromatic nucleophilic substitution

Using the Lewis Acid Me3Si−F−Al(ORF)3 To Prepare Phosphino‐Phosphonium Cations with the Least‐Coordinating Anion [(RFO)3Al−F−Al(ORF)3]−

“…For Me 2 P−SiMe 3 , the resonance structure with covalent bonds as well as the [Me 2 P] − [SiMe 3 ] + resonance structure seem to describe this molecule correctly. This is in agreement with the published reaction mechanism of the phosphinodefluorination of fluorobenzenes, for which this class of compounds may be used. However, the calculated dipole moment of only 0.3 D (gas phase) up to 0.5 D (COSMO, ϵ =∞) suggests that the neutral Lewis formula dominates.…”

Concerted Nucleophilic Aromatic Substitution Reactions

“…Ther ange of nucleophiles was further widened when Würthwein et al reported the reaction of di-and trifluorobenzenes 204-206 with Me 2 EM (E = P, N; M= SiMe 3 ,SnMe 3 Li)( Scheme 30). [67,68] To illustrate the utility of the transformation, phosphane products were later used as ligands in polyfluorophosphane palladium dichloride complexes.C omputational chemistry was again shown to be au seful tool in predicting the mechanism of this reaction, indicating asingle transition state with no Meisenheimer adduct formation, that is,acS N Ar mechanism.…”

“…The range of nucleophiles was further widened when Würthwein et al. reported the reaction of di‐ and trifluorobenzenes 204 – 206 with Me 2 EM (E=P, N; M=SiMe 3 , SnMe 3 Li) (Scheme ) . To illustrate the utility of the transformation, phosphane products were later used as ligands in polyfluorophosphane palladium dichloride complexes.…”

Konzertierte nukleophile aromatische Substitutionen

“…P-, N-, Si-und C-Nukleophile Ein breites Spektrum von Nukleophilen wurde von Würthwein et al in ihrer Studie der Reaktion der Di-und Tr ifluorbenzole 204-206 mit Me 2 EM (E = P, N; M= SiMe 3 , SnMe 3 ,L i) eingesetzt (Schema 30) [67,68]. Um die Nützlichkeit der Transformation zu veranschaulichen, wurden die erzeugten Phosphanprodukte später als Liganden in Polyfluorphosphan-Palladiumdichlorid-Komplexen verwendet.…”