The CF Group as a Synthon of the CF Unit in Palladium Chemistry.

The homoleptic trifluoromethyl-palladium(II) complex [Pd(CF)] (1) is shown to be highly active towards amines. Thus, when treated with primary amines RNH, it readily undergoes aminolysis of one of the CF ligands affording the isocyanide complexes [(CF)Pd(CNR)] (R=aryl). In this process the original CF group undergoes total defluorination.

Synthesis and Lewis Acid Properties of Neutral Silver(III) Adducts Containing the Ag(CF) Moiety.

The acetonitrile Ag complex [Ag(CF)(NCCH)] (2) has been reported independently by Eujen and Naumann in the last century, albeit with intriguing NMR discrepancy. In their reports, 2 was claimed to be obtained starting from either [Ag(CF)Cl] (3⋅) or [Ag(CF)] (1) via halide abstraction using AgNO or acidic treatment, resp. These two synthetic routes are herein reinvestigated.

The Fluoride Method: Access to Silver(III) NHC Complexes.

We have synthesized the first silver(III) carbene complexes, (CF ) Ag(NHC), by direct reaction of the silver(III) fluoride precursor complex [PPh ][(CF ) AgF] with different imidazolium salts. This novel methodology circumvents the use of free NHC molecules. The silver(III) carbene complexes thus prepared are unprecedented and show remarkable thermal stabilities.

An Organocopper(III) Fluoride Triggering C-CF Bond Formation.

Copper(III) fluorides are catalytically competent, yet elusive, intermediates in cross-coupling. The synthesis of [PPh ][Cu (CF ) F] (2), the first stable (isolable) Cu -F, was accomplished via chloride addition to [Cu (CF ) (py)] (1) yielding [PPh ][Cu (CF ) Cl(py)] (1⋅Cl), followed by treatment with AgF. The Cu halides 1⋅Cl and 2 were fully characterized using nuclear magnetic resonance (NMR) spectroscopy, single crystal X-ray diffraction (Sc-XRD) and elemental analysis (EA).

Cross-Coupling Reactions Enabled by Well-Defined Ag(III) Compounds: Main Focus on Aromatic Fluorination and Trifluoromethylation.

Ag compounds are considered strong oxidizers of difficult handling. Accordingly, the involvement of Ag catalysts in cross-coupling via 2e redox sequences is frequently discarded. Nevertheless, organosilver(III) compounds have been authenticated using tetradentate macrocycles or perfluorinated groups as supporting ligands, and since 2014, first examples of cross-coupling enabled by Ag /Ag redox cycles saw light.

Electrophilicity of neutral square-planar organosilver(III) compounds.

Neutral Ag(III) complexes stabilised with just monodentate ligands are here unambiguously established. In a series of square-planar (CF)Ag(L) compounds with hard and soft Group 15 donor ligands, L, the metal center has been found to exhibit substantial acidity favouring apical coordination of an additional ligand under no coordination constraints.

Stability of Ag towards Halides in Organosilver(III) Complexes.

The involvement of silver in two-electron Ag /Ag processes is currently emerging. However, the range of stability of the required and uncommon Ag species is virtually unknown. Here, the stability of Ag towards the whole set of halide ligands in the organosilver(III) complex frame [(CF ) AgX] (X=F, Cl, Br, I, At) is theoretically analyzed.

The First Organosilver(III) Fluoride, [PPh ][(CF ) AgF].

Organosilver(III) fluoride complexes have been assigned a key role in different fluorination processes. To the best of our knowledge, however, none of them seem to have been isolated or even detected thus far. Here we report on the successful synthesis of the trifluoromethyl derivative [PPh ][(CF ) AgF], which has been isolated in high yield.

M-C Bond Homolysis in Coinage-Metal [M(CF ) ] Derivatives.

A comparative study of the homoleptic [M(CF ) ] complexes of all three coinage metals (M=Cu, Ag, Au) reveals that homolytic M-C bond cleavage is favoured in every case upon excitation in the gas phase (CID-MS ). Homolysis also occurs in solution by photochemical excitation. Transfer of the photogenerated CF radicals to both aryl and alkyl carbon atoms was also confirmed.

Homoleptic Trifluoromethyl Derivatives of Ag and Ag.

The homoleptic silver(I) compound [PPh ][CF AgCF ] (1) provides a convenient entry to the homoleptic silver(III) derivative [PPh ][Ag(CF ) ] (2). Once isolated as pure substances, these compounds exhibit marked thermal stabilities. Their structural and spectroscopic properties have been experimentally established.