Catalytic Hydrodefluorination via Oxidative Addition, Ligand Metathesis, and Reductive Elimination at Bi(I)/Bi(III) Centers

Herein, we report a hydrodefluorination reaction of polyfluoroarenes catalyzed by bismuthinidenes, Phebox-Bi(I) and OMe-Phebox-Bi(I). Mechanistic studies on the elementary steps support a Bi(I)/Bi(III) redox cycle that comprises C(sp²)-F oxidative addition, F/H ligand metathesis, and C(sp²)-H reductive elimination. Isolation and characterization of a cationic Phebox-Bi(III)(4-tetrafluoropyridyl) triflate manifests the feasible oxidative addition of Phebox-Bi(I) into the C(sp²)-F bond. Spectroscopic evidence was provided for the formation of a transient Phebox-Bi(III)(4-tetrafluoropyridyl) hydride during catalysis, which decomposes at low temperature to afford the corresponding C(sp²)-H bond while regenerating the propagating Phebox-Bi(I). This protocol represents a distinct catalytic example where a main-group center performs three elementary organometallic steps in a low-valent redox manifold.

Halogen bonding between entirely negative fluorine atoms? Evidence from the crystal packing of some gold(i) and gold(iii) complexes with extensively fluorinated m-terphenyl ligands and triphenylphosphane

Intermolecular interactions between fluorine atoms, analogous to halogen bonding, are able to drive the solid-state arrangement of molecules.

One-Pot Synthesis of Hypervalent Diaryl(iodo)bismuthanes from o-Carbonyl Iodoarenes by Zincation

Diaryl(iodo)bismuthanes possessing a hypervalent C=O•••Bi–I bond were conveniently synthesized in a one-pot reaction by using arylzinc reagents generated from o-carbonyl iodobenzenes and zinc powder under ultrasonication. This method is superior to the conventional organolithium and Grignard methods because it has a wide functional group tolerance, requires no protecting group manipulations, and proceeds under mild reaction conditions that do not need low temperature control. Furthermore, no intermediate triarylbismuthane precursor for the hypervalent iodobismuthane is necessary.

Experimental evidence for hypercoordination in triorganotelluronium halides with 2-(Me2NCH2)C6H4 groups

Triorganotelluronium halides of type [{2-(Me₂NCH₂)C₆H₄}_nPh_3−nTe]⁺X⁻ (n = 1–3, X = Cl, Br, I) were prepared and structurally characterized both in solution and in the solid state, showing a (C,N)-chelating behavior of the 2-(Me₂NCH₂)C₆H₄ groups.