Unprecedented bonding of a coordinated polyenyl ligand. Synthesis and molecular structures of fac-trialkyltricarbonyliron compounds containing the .eta.3-nonafluorocycloocta-2,5-diene-1,4,7-triyl ligand and its derivatives

Regioselective CF Bond Activation of Hexafluoropropylene on Palladium(0): Formation of a Cationic η2‐Perfluoroallylpalladium Complex

“…Significant structural features of (E)-7 a included cleavage of the cis C(sp 2 )ÀF bond with respect to the CF 3 group of 1 along with one of the fluorine atoms in the tetrafluoroborate bridges between the palladium and boron atoms. In the 19 F NMR spectrum of (E)-7 a, resonances that were assignable to the (E)-perfluoro-prop-1-en-1-yl group appeared at d F = À65.2 (br, 3 F), À76.4 (br, 1 F), and À145.5 ppm (m, 1 F), whereas a characteristic 3 J(trans) coupling constant of 119 Hz was observed in the minor isomer (Z)-7 a.…”

“…The fluorine atoms bound to the allylic carbon atom in 4 a were chemically inequivalent and regarded as resonance set at d F = À65.6 and À97.0 ppm with a 2 J FF coupling constant of 312.5 Hz. In addition, the 19 F NMR spectrum of 4 a displayed three resonances at d F = À103.3, À108.4, and À195.7 ppm, which were attributable to the CF 2 = CF-moiety. Although stoichiometric, these reactions were the first substitution reaction of the allylic fluorine in 1 with a nonhydrogen atom.…”

“…A reversible dissociation of the carbonyl ligand in 6 a to regenerate 3 a was observed when a CD 2 Cl 2 solution of 6 a was concentrated under reduced pressure. In the 19 F NMR spectrum of 6 a, an h 1 -perfluoroallyl ligand appeared at d F = À61.9 (br, 2 F), À94.9 (dd,53.8,32.0 Hz,1 F),À105.5 (ddt,112.6,53.8,14.5 Hz,1 F),and À167.3 ppm (br d,112.6 Hz,1 F). The observation of the 31 P resonance (t, J PF = 21.6 Hz) confirmed the trans geometry around the palladium center in 6 a.…”

Fluorine as a ligand substituent in organometallic chemistry: A second chance and a second research career

“…The chemistry of the coordinated ligands also proved to be quite different; while 1 reacted with tertiary phosphines to displace COT from the coordination sphere [27], 2 reacted with PMe 3 by exoselective nucleophilic attack at the internal carbon of the h 3 -allylic part of the ligand, to give the zwitterionic complex 3, providing three fluorines with their preferred locations on sp 3 carbons (Scheme 1) [28]. In analogous fashion a new C-F bond could be formed by reaction of 2 with a source of fluoride anion to give 4 and in a reaction type which was to become important later on, the CF 2 group in 4 underwent rapid hydrolysis to give the ketone functionality in 5 (Scheme 1) [28].…”

“…In analogous fashion a new C-F bond could be formed by reaction of 2 with a source of fluoride anion to give 4 and in a reaction type which was to become important later on, the CF 2 group in 4 underwent rapid hydrolysis to give the ketone functionality in 5 (Scheme 1) [28]. Somewhat ironically, this is [ ( F i g .…”