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The first pyrroloazaphosphinines with nitrogen at the junction, 7a and 7b, have been prepared by a special route involving the collapse of the phosphorus bridges of appropriate 7-phosphanorbornenes. The parent molecule 7a has a strictly planar azaphosphinine ring with some electronic delocalization according to DFT computations. Its P=C double bond does not react with 2,3-dimethylbutadiene unless P is coordinated toMo(CO)5. Compound 7a reacts with CuI to give a new type of polymeric complex [–Cu-μ2-7a–]n in which P acts as a bridging ligand and the ligand planes are antiparallel. The benzo-annulated and bromo-substituted 7b displays a skewed ring according to DFT computations and its P=C double bond is reactive toward 2,3-dimethylbutadiene without complexation. [ABSTRACT FROM AUTHOR]

The stabilization of a phosphirane ring by complexation to tungsten pentacarbonyl allows the emergence of the Cloke-Wilson rearrangement in 1-acylphosphirane complexes around 130 °C. Contrary to the cyclopropane case, this transformation of the 1-acylphosphirane to the 1,3-oxaphosphol-3-ene complexes is reversible. It is favored by a 2-phenyl, and even a 2-vinyl substitution. The 1,3-oxaphosphol-3-ene complexes are trapped by conjugated dienes. [ABSTRACT FROM AUTHOR]

Treatment of ortho-(diphenylphosphanyl)phenyl nitriles with an excess of lithium at room temperature in THF gives 1,2-azaphosphindolides, which can react with RX (benzyl bromide, 1-bromopropane, and 1,2-dibromoethane) to form 2H-1,2-azaphosphindoles and give the aromatic 1H-1,2-azaphosphindoles upon protonation. [ABSTRACT FROM AUTHOR]

ortho-Phosphinobenzonitriles (or thieno, pyridino analogues) react with dimethyl acetylenedicarboxylate between -78 °C and room temperature to give annelated λ5-phosphanaphthalenes. Interesting variations of the fluorescence properties are observed when the R substituents at P are alkyl or aryl. When R = tBu, the thermolysis of the product affords the corresponding trivalent phosphanaphthalene. [ABSTRACT FROM AUTHOR]

The reaction of terminal phosphinidene complexes [RP-W(CO)5] with vinylboronic acids is very sensitive to the presence or absence of solid K3PO4 in suspension in the reaction medium. The products are phosphirane complexes without the salt and secondary vinylphosphine complexes in the presence of the salt. This shift of the reaction pathway is explained by the formation of vinyborates in the presence of potassium phosphate. [ABSTRACT FROM AUTHOR]

Aluminum trichloride catalyzes the ring opening of a 1-chlorophosphirane W(CO)5 complex and its reaction with thiophene and ferrocene to give the corresponding 1-(2-thienyl)- and 1-ferrocenylphosphirane derivatives. The W(CO)5 complex of the 1-ferrocenylphosphirane is an efficient precursor of the phosphinidene complex [FcP-W(CO)5], which is trapped by tolan, trans-stilbene, and water. [ABSTRACT FROM AUTHOR]

An original approach involving a coupling in the gas phase between flash vacuum thermolysis (FVT) and UV-photoelectron spectroscopy (UV-PES) allowed the transient terminal electrophilic phosphanylidene complex [MeP=W(CO)5] to be characterized; this is the first direct observation of this P-Me derivative. This approach also permitted the electronic structure of [PhP=W(CO)5] to be revisited and confirmed the results obtained with the methylated analogues. In contrast, [ p-NC-C6H4P=W(CO)5] proved to be too reactive to be detected under our experimental conditions. These [RP=W(CO)5] phosphanylidene complexes (R: Me, Ph) were identified by their ionization potentials, which are real 'fingerprints'. These experimental data, supported by density functional calculations, give an overall electronic cartography of these transient species. For generation in the gas phase of these phosphanylidene complexes, the thermal degradation of two kinds of precursors were investigated. The joint experimental/theoretical approach allowed us to conclude that phosphanorbornadiene complexes are more suitable precursors than phosphirane complexes. [ABSTRACT FROM AUTHOR]

Recent developments in the chemisty of 1-phosphanorbornadienes are reviewed. Due to their bicyclic structure with a non-racemisable phosphorus atom at the bridgehead, they are ideally suited to enantioselective catalysis as transition metal complexes. Amongst this family, two enantiopure species play a special role, i.e., the so-called BIPNOR, a 2,2′-bis-1,1′-phosphanorbornadienyl ( 1 ), and a 2-formyl-1-phosphanorbornadiene ( 2 ). BIPNOR displays high enantioselectivities for a range of rhodium-catalyzed reactions. The carboxyaldehyde ( 2 ) is an ideal starting point for the synthesis of a series of enantiopure chelating 1-phosphanorbornadienes whose structures can be optimized for various catalytic enantioselective reactions. Examples of both approaches are given. [ABSTRACT FROM AUTHOR]

This account describes the development of phosphametallocene chemistry from the discovery of phosphacymantrenes in 1976 and phosphaferrocenes in 1977, to the preparation of paramagnetic and main group derivatives and to the development of catalytic applications starting in 1995. It does not intend to be comprehensive and is mainly focused on the work of the author''s group. [Copyright &y& Elsevier]

Reaction of 1-chloro-2,3,4,5-tetraethylphosphole with lithium yields the tetraethylphospholyl anion which is homocoupled to form the 1,1′-bis-(tetraethylphosphole) upon reaction with iodine. The thermal reaction of this bis-(tetraethylphosphole) with the [FeCp*(CO)2]2 dimer (Cp*=C5Me5) affords the pentamethylcyclopentadienyl-tetraethylphosphaferrocene. Reaction of this phosphaferrocene with elemental iodine in dichloromethane at room temperature affords the corresponding pentamethylcyclopentadienyl-tetraethylphosphaferrocenium [Fe(Cp*)(C12H20P)][I3] complex which was structurally characterized. The complex adopts a full-eclipsed geometry. As usually observed in classical ferrocenes, oxidation of the Fe center to +3 oxidation state results in a lengthening of the centroid-Fe bond distances. [Copyright &y& Elsevier]

A polycyclic imidazolophosphinine has been synthesized by collapse of the bridge of an appropriate 7-phosphanorbornene. This stable compound has been characterized by X-ray crystal structure analysis. It is fully planar with a P=C bond length of 1.733(4) Å. The lone pair at P is poorly reactive and corresponds to HOMO-3. The compound reacts with a protic acid and methyl iodide at the sp² nitrogen and with AuCl with the a-methoxy substituent, yielding a zwitterionicacylphosphidewhose complexation at P gives a bis-gold complex. Both the protonated product and the bis-gold complex have been characterized by X-ray crystal structure analysis. [ABSTRACT FROM AUTHOR]

The article discusses the abnormal hydrolysis of 7-phosphanorbornenium salts to get a phosphinous acid. It is stated that phosphonium salt hydrolysis is a fundamental reaction in organophosphorous chemistry but it has been discovered that reductive elimination can occur when the salt is in a five-membered ring. It notes that the phosphonium salt can become equivalent to a phosphenium ion. It also mentions the density functional theory calculations performed to rationalize the findings.

Stabilised phosphorus ylides react with transient terminal phosphinidene complexes [RP&z.sbnd;W(CO)5] (R=Ph, Me) to give products resulting from a formal insertion of P into a C&z.sbnd;H bond via an initial nucleophilic attack of the ylidic carbon. [Copyright &y& Elsevier]