Reaction Of Phosphine Research Articles

C2-Symmetric Iron(II) Diphosphine–Dialkoxide Dicarbonyl and Related Complexes

Reaction of Fe(bda)(CO)3 (bda = benzylideneacetone) and Ph2P-2-C6H4CHO (PCHO) affords the bisphosphine bisalkoxide complex Fe[(Ph2PC6H4)2C2H2O2](CO)2 (1) arising from the head-to-head coupling of two formyl groups concomitant with oxidation of Fe(0) to Fe(II). Crystallographic studies show that 1 features cis alkoxide ligands that are trans to CO; the two phosphine groups are mutually trans with a P–Fe–P angle of 167.44(4)°. The pathway leading to 1 was examined, starting with the adduct Fe(PCHO)(CO)4 (2), which was obtained by addition of PCHO to Fe2(CO)9. Compound 2 decarbonylates to give tricarbonyl Fe(κ1,η2-PCHO)(CO)3 (3), which features a π-bonded aldehyde. Photolysis of 2 gives a mixture of 3 and isomeric hydride HFe(κ2-PCO)(CO)3. Complex 3 reacts with an additional equivalent of PCHO to afford 1, whereas treatment with PPh3 afforded the substituted product Fe(κ1,η2-PCHO)(PPh3)(CO)2 (4). In 4, the phosphine ligands are trans and the aldehyde is π-bonded. The geometry around Fe is pseudo trigonal bipyramidal. To gain insights into the mechanism and scope of the C–C coupling reaction, complexes were prepared with the imine Ph2PC6H4CH═NC6H4Cl (abbreviated as PCHNAr), derived by condensation of 4-chloroaniline and PCHO. PCHNAr reacts with Fe2(CO)9 and with Fe(bda)(CO)3 to afford the tetra- and tricarbonyl compounds Fe(PCHNAr)(CO)4 (5) and Fe(PCHNAr)(CO)3 (6), respectively. Treatment of 6 with PCHO gave the unsymmetrical C–C coupling complex Fe[(Ph2PC6H4)2CH(O)CH(NAr)](CO)2 (7). Compound 7 was also prepared by the reaction of 3 and PCHNAr. The solid-state structure of 7, as established by X-ray crystallography, is similar to that of 1 but with an amido group in place of one alkoxide. The deuterium-labeled phosphine aldehyde PCDO was prepared by the reaction of ortho-lithiated phosphine Ph2PC6H4-2-Li with DMF-d7. Reaction of 6 with PCDO gave 7-d1 with no scrambling of the deuterium label. Attempted oxidation of 1 with FcBF4 (Fc+ = ferrocenium) gave the adduct Fe[(Ph2PC6H4)2C2H2O2(BF3)2](CO)2 (8). The structures of 1 and 8 are almost identical. Compound 8 was independently synthesized by treating 1 with BF3OEt2 via the intermediacy of the 1:1 adduct, which was detected spectroscopically. Qualitative tests showed that 1 also reversibly protonates with HOSO2CF3 and binds TiCl4.

N-Type Doping of Germanium from Phosphine: Early Stages Resolved at the Atomic Level

To understand the atomistic doping process of phosphorus in germanium, we present a combined scanning tunneling microscopy, temperature programed desorption, and density functional theory study of the reactions of phosphine with the Ge(001) surface. Combining experimental and theoretical results, we demonstrate that PH(2) + H with a footprint of one Ge dimer is the only product of room temperature chemisorption. Further dissociation requires thermal activation. At saturation coverage, PH(2) + H species self-assemble into ordered patterns leading to phosphorus coverages of up to 0.5 monolayers.

Chemoselective Reactions of Secondary Phosphine Chalcogenides with Vinyloxyalkylamines: Synthesis of a Novel Family of Functional Phosphinoсhalcogenоic Amides

The reactions of secondary phosphine сhalcogenides with vinyloxyalkylamines proceed chemoselectively in triethylamine–carbon tetrachloride under mild conditions to give the corresponding phosphinoсhalcogenоic amides bearing vinyloxy moieties in 78–95% yields.

The dynamics of the C + PH3 reaction: A theoretical study

The C + PH(3) reaction is one of the simplest gas-phase processes which can produce molecular species containing P-C bonds. It could be of astrophysical importance and a reference for other phosphine reactions with carbon-containing molecular radicals. The dynamical aspects have been studied theoretically by quasi-classical trajectory methods in order to determine its rate as a function of the temperature, the branching ratios, and the molecular mechanisms. We have obtained a T(0.2) dependence of the capture rate. The total rate is affected by the existence of relatively high-lying saddle points for the isomerization of the CPH(3) complex but get a value of 0.82·10(-10) cm(3) s(-1) at 300 K, which is considered quite high for a neutral-neutral reaction and higher than those of similar reactions. Moreover, the total rate presents a weak dependence with the temperature. Our results indicate that several products containing P-C bonds are formed, the main reaction channel being the generation of HPCH + H.

Distribution of Phosphorus Atoms and Carrier Concentrations in Single-Crystal Silicon Doped by Catalytically Generated Phosphorous Radicals

A phosphorus (P)-doped ultrathin n+ layer is formed on crystalline silicon (c-Si) using radicals generated by the catalytic cracking reaction of phosphine (PH3) gas with a heated catalyzer. The carrier concentration and the depth distributions of P atoms are investigated by Hall effect and secondary ion mass spectrometry (SIMS), respectively. The surface of the p-type c-Si substrate is converted to n-type c-Si by this doping even at a substrate temperature of 20 °C, when the tungsten (W) catalyzer is heated at 1300 °C. SIMS measurements demonstrate that P atoms exist on the c-Si surface. However, the distributions of P atoms obtained by SIMS do not change, even for the increase in substrate temperature from 80 to 350 °C or the increase in radical exposure time from 60 to 3600 s. Although the sheet carrier concentration increased with the substrate temperature, the sheet carrier concentration increased only slightly with the radical exposure time. It is revealed that the doping mechanism does not appear to be the same as that of the thermal diffusion, but that the reaction of the P-related species with Si atoms on the surface plays a key role for this radical doping.

Quantum chemical investigation on the reaction mechanism of tertiary phosphines with unsaturated carboxylic acids: An insight into kinetic data

AbstractThe structures of intermediates and transition states in the reaction of tertiary phosphines with unsaturated carboxylic acids have been calculated at the B3LYP level of theory using the 6‐31+G(d,p) basis set. Analysis of the results shows that [1,3]‐intramolecular migration of carboxylic proton to carbanionic center of generated zwitterionic intermediate is strongly kinetically unfavorable, and external proton‐donor source is essential to complete quaternization. A molecular cluster of the intermediate with one molecule of water has been modeled for intermolecular reaction pathway, but even in this case, the proton transfer remains to be the rate‐determining step that is in a good agreement with previous kinetic investigations on this reaction. The data obtained for this reaction have much in common with recent studies on the mechanisms of the Morita–Baylis–Hillman reaction and phosphine‐catalyzed [3+2] cycloaddition, which revealed paramount importance of proton‐transfer steps. © 2013 Wiley Periodicals, Inc.

ChemInform Abstract: Palladium‐Catalyzed 1,4‐Addition of Diarylphosphines to α,β‐Unsaturated Aldehydes.

AbstractPincer‐Pd catalyst (Ia) is effective in the 1,4‐addition reaction of diaryl phosphines to α,β‐unsaturated aldehydes to afford the enantioenriched phosphines with high yields and enantioselectivities [cf.

Li Reaction Mechanism of MnP Nanoparticles

MnP nanoparticles (MnPs) with a particle size of <30 nm were prepared by the reaction of dimanganese decacarbonyl and trioctyl phosphine (TOP) at 380°C under Ar atmosphere. Lithium reaction mechanism of the MnPs was investigated by using electrochemical cycling, ex situ X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). When lithium ion was first inserted into the MnP, it started to form LiMnP, LiP and LiP7 phases. During lithium dealloying (charging to 2 V), LiMnP phase was turned into the LiP and LiP5 phases.

Low-temperature Phosphorus Doping To Silicon Using Phosphorus-related Radicals

ABSTRACTPhosphorus (P) doped ultra thin n+-layer is formed on crystalline silicon (c-Si) at low substrate temperatures of 80 – 350 °C using radicals generated by the catalytic reaction of phosphine (PH3) with a tungsten catalyzer heated at 1300 °C. The sheet carrier concentration obtained by Hall effect is in the range between 3×1012cm-2 and 8×1012cm-2. The distribution of P atoms obtained by secondary ion mass spectrometry (SIMS) indicates that P atoms locate within the depth of 4 nm from surface and the profile has almost the same distribution independent of any doping conditions such as substrate temperature or radical exposure time. The sheet carrier concentration is 1.15 – 2.12% of the amount of P atoms incorporated through the radical doping. The ratio of activated donors increases with substrate temperature during the radical doping, suggesting that P-related species bonded on the c-Si surface require thermal energy for their activation. Using the n+-layer formed by radical doping, the reduction of surface recombination velocity for n-type c-Si wafer is attempted. The effective minority carrier lifetime of the n-type c-Si sample covered with 6-nm-thick intrinsic amorphous Si (i-a-Si) layers on both side increases from 32 μs to1576 μs by the radical doping of P atoms to n-type c-Si surface, suggesting that the radical doping can be utilized for the formation of passivation layers on a-Si/ n-c-Si hetero-interface.

Size and shape assessment of organometallic gold(I) metallodendrimers through PGSE-NMR and molecular dynamics simulations

The reactions of the amino-terminated PAMAM-dendrimers (generations 0–2) with Ph2PCH2OH in the appropriate molar ratios give rise to the dendritic phosphines PAMAM-GZ-(N(CH2PPh2)2)n (Z=0, n=4 (1), Z=1, n=8 (2) and Z=2, n=16 (3)). Further reaction of phosphines 1–3 with one equivalent of [Au(C6F5)(tht)] (tht=tetrahydrothiophene) per P-donor site leads to metallodendrimers [{Au(C6F5)}2n{PAMAM-GZ-(N-(CH2PPh2)2)n}] (Z=0, n=4 (4), Z=1, n=8 (5) and Z=2, n=16 (6)). Phosphines 1–3 and metallodendrimers 4–6 have been characterized by 1H, 19F and 31P{1H} NMR spectroscopy and through IR spectroscopy. 1H PGSE NMR studies of the dendritic phosphines and the metallodendrimers permit the evaluation and comparison of the different molecular sizes through their corresponding hydrodynamic radius, depending on the dendrimer generation and on the coordination of the organometallic fragments [Au(C6F5)]. Molecular dynamics simulations allow the theoretical estimation of the macromolecular size through the calculation of the radius of gyration for each species and the calculation of the dendrimer flexibility.

ChemInform Abstract: Three‐Component and Nonclassical Reaction of Phosphines with Enynes and Aldehydes: Formation of γ‐Lactones Featuring α‐Phosphorus Ylides.

AbstractThe highly functionalized title compounds are generated by an unusual α‐addition of aromatic phosphines to the triple bond.

Catalytic Palladium Phosphination: Modular Synthesis of C1‐Symmetric Biaryl‐Based Diphosphines

A new family of C(1)-symmetric bis(diphenylphosphino)biphenyls have been prepared starting from readily available ortho,ortho'-dihalobiphenyl precursors by a palladium-catalyzed C-P coupling reaction. This process does not require the use of an additional ligand. To date, the synthesis of such diphosphines, by reaction of an intermediate biphenyldiyl dianion with ClPPh(2), mainly afforded the undesired cyclic phosphafluorene derivative. So far, no synthetic pathway has been found to avoid this intramolecular reaction. Herein we report the first general and external-ligand-free palladium-catalyzed phosphination reaction that allows the synthesis of a wide variety of substituted ortho,ortho'-bis(diphenylphosphino)biphenyls. With the aim of illustrating the scope and efficiency of this methodology, we applied it to the establishment of a straightforward access to C(1)-symmetrical analogues of the most powerful ligands used in homogenous catalysis and extended it to more challenging substrates.

ChemInform Abstract: Selective Synthesis of Hydrazinium Diselenophosphinates from Secondary Phosphines, Elementary Selenium, and Hydrazine.

A three-component reaction of secondary phosphines, elementary selenium, and hydra zine hydrate (the molar ratio 1: 2: 1.1) selectively proceeds under mild conditions (EtOH, 70-75°C, 0.5 h) to form earlier unknown hydrazinium diselenophosphinates (81-95%).

Three-Component and Nonclassical Reaction of Phosphines with Enynes and Aldehydes: Formation of γ-Lactones Featuring α-Phosphorus Ylides

Inverted carbenoid species, generated from attack of phosphines at the α(δ')-carbon of hex-2-en-4-ynedioic acid dialkyl esters, react with aldehydes to give γ-lactones possessing an α-phosphorus ylide moiety.

Kinetic Study of the Reaction of Tertiary Phosphines with Acrylic Acid in Aprotic Solvents

The kinetics of the reaction of tertiary phosphines with acrylic acid in a series of aprotic solvents was studied by spectrophotometry. The data obtained suggest a stepwise mechanism of interaction including initial formation of zwitterionic intermediate followed by intermolecular proton transfer to the generated carbanionic center from the second molecule of acrylic acid.

Kinetics and Mechanism of Triphenylphosphine Quarternization with Unsaturated Carboxylic Acids in Various Media

Reactions of tertiary phosphines with unsaturated electrophilic reagents are widely used in synthetic organic chemistry. Typical satellites of these transformations are proton migration processes, which can play decisive role in such reactions. To learn more about proton transfer mechanism, kinetics of reaction of triphenylphosphine with a series of unsaturated carboxylic acids in alcohols, carboxylic acids, and aprotic solvents was studied by spectrophotometry. The form of kinetic equation depends on proton–donor properties of solvent and has a general third order. Proton transfer occurs from the solvent in carboxylic acids; the second molecule of substrate is required in aprotic solvents, and both canals of proton migration take place in alcohols. Existent proton transfer canals are isokinetic, attesting to the invariability of general features of the reaction mechanism independent of proton–donor nature at the last step of the interaction. A stepwise mechanism including initial generation of 1,3-dipole followed by proton transfer to the carbanionic centre from the medium is suggested.

α-Phosphino Amino Acids: Synthesis, Structure, and Reactivity

One-pot three-component reactions of secondary or primary phosphines and primary amines with glyoxylic acid provide a wide variety of acyclic or cyclic phosphinoglycines, in the case of some chiral amines with high diastereoselectivity. The structure, hydrolysis, oxidation, coordination at M(CO)5 (M = Cr, Mo, W), and use in nickel-catalyzed ethylene oligomerization were studied.

Stereoselective Palladium Catalyzed Allylic Phosphination

AbstractChiral enantiopure 2‐5‐diphenylphospholane borane 8 is an interesting nucleophile for allylic phosphination in the presence of palladium complexes to form CP bonds. A highly diastereoselective allylic phosphination reaction was realized using chiral palladium‐DACH‐naphthyl (DACH=1,2‐diaminocyclohexane) ligand as the catalyst system. The secondary phosphine‐borane complex could be classified as a NuL type nucleophile.

Synthesis of tris(organylthioethyl)phosphines and their derivatives on the basis of the reaction of phosphine with vinyl sulfides

Phosphine generated from the red phosphorus in the system KOH-H2O-toluene adds regio- and chemoselectively to vinyl sulfides under radical initiation conditions with the formation of tris(2-organylthioethyl)phosphines, which are easily oxidized by elemental sulfur and selenium to the corresponding phosphine sulfides and phosphine selenides in 54–78% yield. The obtained adducts are split when treated with sodium amide in THF to give trivinylphosphine and trivinylphosphine chalcogenides.

Reactions of phosphines with aluminum carbenoids

Metal carbenoids are known as highly reactive compounds that are often used as intermediates in the organic synthesis [1, 2]. We formerly studied the reactions with acetylenes of various structures of aluminum carbenoids obtained in situ from CH2I2 and trialkylalanes [3–5]. It was established that the structure of compounds obtained and the mechanism of their formation essentially depended on the nature of the substituent at the acetylene bond. In order to elucidate the role of the nature of the substituent at the acetylene bond we studied the transformation of organophosphorus acetylenes under the action of the aluminum carbenoids. The reaction of hex-1-yn-1-yl(diphenyl)phosphine with the obtained in situ diethyl(iodomethyl)aluminum Et2AlCH2I [6] after treating the mixture with deuterium oxide afforded 1-hexynyl-(deuteromethyl) diphenylphosphonium iodide (Iа) in a quantitative yield. The structure of the compound obtained was confi rmed by an authentic synthesis of hex-1-yn-1-yl(diphenyl) phosphonium iodide (IIa) by the reaction of hex-1-yn1-yl(diphenyl)phosphine with 1 equiv of MeI without solvent The 13C and 1H NMR spectra of thus prepared phosphonium salt and the hydrolysis product of the reaction mixture were identical. In the 13C NMR spectrum of compound Ia a doublet of triplets was observed at δ 14.00 ppm due to the coupling of carbon atom with phosphorus and deuterium nuclei. Thus it was established that the reaction of (hex-1yn-1-yl)diphenylphosphine with aluminum carbenoid Et2AlCH2I led to the formation of a phosphonium salt, and the acetylene bond was not involved into the reaction. In this case the C–I bond in the aluminum carbenoid was more reactive than the metal–carbon bond. Besides the