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Phosphine complexes of cobalt halide salts activated by diethylaluminum chloride are shown to yield highly active catalysts in the hydrovinylation of styrene, with unprecedented high selectivity to the desired product 3phenyl1butene 3P1B. Doublebond isomerization, a common problem in codimerization reactions, only occurs after full conversion with these catalyst systems, even at elevated temperature. The most active catalysts are based on cobalt halide species combined with either C1 or C2bridged diphosphines, heterodonor P,N or P,O ligands, flexible bidentate phosphine ligands or monodentate phosphine ligands. Kinetic investigations show an order >1 in catalyst, which indicates either the involvement of dinuclear species in the catalytic cycle or partial catalyst decomposition viaa bimolecular pathway.

A new catalytic method has been investigated to obtain either O or Callylated phenolic products using allyl alcohol or diallyl ether as the allyl donor. With the use of new cationic rutheniumII complexes as catalyst, both reactions can be performed with good selectivity. Active cationic RuII complexes, having cyclopentadienyl and bidentate phosphine ligands are generated from the corresponding RuII chloride complexes with a silver salt. The structures of three novel diphosphineRuIICpCl catalyst precursor complexes are reported. It appears that the structure of the bidentate ligand has a major influence on catalytic activity as well as chemoselectivity. In addition, a strong cocatalytic effect of small amounts of acid is revealed. Model experiments are described that have been used to build a reaction network that explains the origin and evolution in time of both Oallylated and Callylated phenolic products. Some mechanistic implications of the observed structure vs.performance relation of the diphosphineRuCpcomplexes and the cocatalytic role of added protons are discussed.

Generating the transient electrophilic tungsten pentacarbonylphenylphosphinidene complex PhPWCO5in the presence of 2,7dimethylocta2,3,5,6tetraene leads to the formation of a 3,4disubstituted phosphole or a complexed phospholene, depending on the reaction conditions. The formation of the phospholene results from the reaction of PhPWCO5with the diallene, while the formation of the phosphole arises from reaction with 3,4diisopropylidenecyclobutene, which is formed in situfrom the isomerization of the conjugated allene.

Ein bewegliches Molekül: Die Umsetzung von insitu erzeugten Phosphinidenen mit Phosphaalkinen eröffnet einen einfachen Zugang zum neuen metallkoordinierten η3Diphosphavinylcarben 1, das leicht Ligandenaustauschreaktionen und eine neuartige Umlagerung eingeht, an welcher der Phosphinidenkomplex 2und der η3Phosphaalkenylphosphinidenkomplex 3, das 1,3Isomer von 1, beteiligt sind.

P machts möglich: Angesichts der leichten oxidativen Synthese des gezeigten 16ElektronenSandwichkomplexes Feη4P2C2tBu22 ist gut denkbar, dass auch der schwer zu fassende Komplex Feη4C4H42 mit reinen Kohlenwasserstoffliganden hergestellt werden könnte.

Do the twist: The reaction of in situ generated phosphinidenes with phosphaalkynes is a facile route to the new metalcoordinated η3diphosphavinylcarbene 1, which shows facile ligandexchange reactions and undergoes an unprecedented rearrangement that involves phosphinidene complex 2and η3phosphaalkenylphosphinidene complex 3, the 1,3 isomer of 1.

P makes it possible: The convenient oxidative synthesis of the 16electron organophosphorus iron sandwich complex Feη4P2C2tBu22 see structure suggests that the elusive allcarbon complex Feη4C4H42 is a viable synthetic target.

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AbstractThe X-ray structure of the title compound has been determined together with spectroscopical properties. The structure consists of a monomeric Cu(II) unit and two nitrate anions. The two bis(2-methylbenzimidazole) ligands are in cispositions.

AbstractThe X-ray structure of the title compound has been determined together with spectroscopical measurements. The structure forms an infinite alternating one-dimensional polymeric structure viathe μ-1,3-bridging azido anion and chelating bipym ligands.

Ein Phosphoranalogondes Komplexes Bisη4cyclobutadieneisen0 wird von K. Lammertsma etal. in ihrer Zuschrift auf S.3150ff.vorgestellt. Im Hintergrund des Titelbilds posiert John Montagu 1718–1792, 4th Earl of Sandwich und Erster Lord der Admiralität, der es sich sicherlich nicht hätte träumen lassen, dass eines Tages eine wichtige Klasse von Organometallverbindungen nach ihm benannt werden würde. Die Synthese von FeP2C2tBu22 belegt, dass die SandwichKomplexe immer noch ein aktuelles Forschungsgebiet sind.

A rare phosphorus analogueof the elusive complex bisη4cyclobutadieneiron0 is reported by K. Lammertsma etal. in their Communication on page3104ff.The background of the cover picture shows John Montagu 1718–1792, 4th Earl of Sandwich and 1st Lord of the Admiralty, who certainly would not have dreamt that an important class of organometallic compounds, sandwich complexes, would bear his name one day. The synthesis of FeP2C2tBu22 shows that sandwich complexes are still topical objects of research.