Transition metal-free hydrodefluorination of acid fluorides and organofluorines by Ph₃GeH promoted by catalytic [Ph₃C][B(C₆F₅)₄]

Abstract

The germylium cation [Ph3Ge]+converts aryl and aliphatic acid fluorides directly to their corresponding aldehydes. Hydrodefluorination of organofluorine compounds by [Ph3Ge]+was also observed.

Fate of Cobaltacycles in Cp*Co-Mediated C–H Bond Functionalization Catalysis: Cobaltacycles May Collapse upon Oxidation via Co(IV) Species

“…19 The tritylium species [Ph 3 C] + , which undergoes a swift decomposition 20 in the gas phase, is in solution a wellknown stable multifaceted Lewis acidic cation. 21 It may act not only as a hydride 22 and/or a halide 23 abstraction agent but also as a one-electron oxidant 24 (Ph 3 C • /Ph 3 C + couple 25 ) in the ground state as well as in the excited state 26 and may be involved also in the hydride abstraction process as reported by Mandon, Astruc, et al 27 Quite interestingly, to the best of our knowledge there has been no mention of any major drawbacks related to the oxidative properties of the tritylium as an "activator", i.e. as a halido ligand "remover", in transitionmetal-mediated homogeneous catalysis.…”

C–F activation reactions at germylium ions: dehydrofluorination of fluoralkanes

“…In addition, [Et 3 Ge] + or [nBu 3 Ge] + favour a reaction pathway towards the dehydrofluorination, although under neat conditions with [Ph 3 Ge] + selectivity towards hydrodefluorination was reported. 6 Overall, the presented results open opportunities for the development of reactions routes for defluorination of fluorinated alkanes. G. M. acknowledges the graduate school SALSA (School of Analytical Science Adlershof).…”

“…5i Catalytic hydrodefluorination reactions have also been recently published by Weinert and co-workers using in situ formed [Ph 3 Ge][B(C 6 F 5 ) 4 ] ions in neat substrates. 6 However, literature known trialkyl germylium ions are limited to [R 3 Ge] + (R = Me, Et) stabilized by carborane anions and no studies on bond activation reactions are known. 5d,g In general, investigations on the reactivity of germylium ions towards organic compounds are very scarce 5i,l,n,o,6 and so far, stoichiometric C-F bond activation reactions have not been studied.…”

Decarboxylative Cross-Coupling of Acyl Fluorides with Potassium Perfluorobenzoates

“…As organic electrophiles for cross-couplings, acyl fluorides can easily be prepared from the corresponding carboxylic acids . In recent years, acyl fluorides have attracted a great deal of attention due to their powerful capabilities in various decarbonylative cross-coupling reactions. , Furthermore, acyl fluorides have served as acyl sources under transition metal catalysis to generate various aldehydes , and ketones in a carbonyl-retentive manner. During the course of our continuing studies of the transition metal-catalyzed transformations of acyl fluorides, we have encountered unique reactivities of the C­(acyl)–F bond.…”