Facile Decarboxylation of Propiolic Acid on a Ruthenium Center and Related Chemistry

Iron vs. ruthenium: syntheses, structures and IR spectroelectrochemical characterisation of half-sandwich Group 8 acetylide complexes

A synthetic ‘trick’ affording complexes [M(CCR)(dppe)Cp′] (M = Fe, Ru) in high purity directly from the reaction vessel is described.

An Ru-Substituted Tris(ethynyl)methyl Cation: Synthesis, Properties, and Structure of [{Cp(dppe)Ru(C≡C)}3C]PF6·C6H6

The dark blue complex [{Cp(dppe)Ru(C≡C)}3C]PF6 1 (Cp=cyclopentadienyl, dppe=1,2-bis(diphenylphosphino)ethane) was obtained in 46% yield by treatment of Ru(C≡CH)(dppe)Cp with CuCl/TMEDA (tetramethylethanediamine), followed by KOH and [NH4]PF6 in acetone; it was accompanied by known complexes {Cp(dppe)Ru}C≡CC≡C{Ru(dppe)Cp} 2 (22%) and yellow [1,3-{Cp(dppe)Ru}2C4H3]PF6 3 (2.6%). The structure of the cationic fragment of 1 in its benzene solvate consists of a central planar C attached to three C≡CRu(dppe)Cp fragments. The cation of 3 consists of a cyclobuten-1,3-diyl group bearing two Ru(dppe)Cp groups. The 13C NMR resonance of the central C in 1 is found at δ 66.11. The cyclic voltammogram of 1 contains three irreversible oxidation waves at +0.87, +0.79, and +0.25V, together with a reversible reduction wave at −1.38V (versus FeCp2/[FeCp2]+).

Solvent- and anion-dependent rearrangement of fluorinated carbene ligands provides access to fluorinated alkenes

The construction of fluorocarbene ligands using sequential nucleophilic and electrophilic addition to a ruthenium vinylidene complex is described. These undergo solvent- and anion-dependent rearrangement to liberate free fluorinated alkenes.

Sequential Reactions of Alkynes on an Iridium(III) Single Site

Sequential insertion of terminal alkynes on Ir^III cyclometalated complexes allow the formation of novel metallapolycycles in a controlled and efficient manner. ortho-Methylarylethynyl derivatives led to an unprecedented cascade combination of three fundamental processes (C-C bond formation, C(sp³ )-H activation, and reductive coupling) on a single Ir^III center, in a process compatible with functionalized biomolecules and photoactive substrates. The reaction with tert-butylacetylene led to a [6,5,4]-polycycle that incorporates an iridacyclobutenylidene in its structure. The sequence is a multicomponent reaction in which the metal not only promotes the different steps but also determines their stereoselectivity. This is an elegant example of the synergy between a metal-promoting reaction and a symmetry-defined stereochemistry.

Syntheses, structural characterisation and electronic structures of some simple acyclic amino carbene complexes

Reactions of the vinylidene complexes [M(CCH₂)(PP)Cp′]PF₆ with NH₃ readily afford the acyclic amino carbene complexes [M{C(Me)NH₂}(PP)Cp′]PF₆ [M(PP)Cp′ = Fe(dppe)Cp, Ru(dppe)Cp, Ru(PPh₃)₂Cp, Ru(dppe)Cp*].