- PHOSPHORANES BICYCLIQUES A LIAISON P-H : BASES DE LEWIS POTENTIELLES
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By reaction of Borane Dimethyl Sulfide on the bicyclophosphorane 1 the adduct 2 is obtained with 56 percent yield; by-products 3 and 4 are characterized.
- Contreras, Rosalinda,Houalla, Douraid,Klaebe, Alain,Wolf, Robert
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Read Online
- Can a pentamethylcyclopentadienyl ligand act as a proton-relay in f-element chemistry? Insights from a joint experimental/theoretical study
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Isomerisation of buta-1,2-diene to but-2-yne by (Me5C5)2Yb is a thermodynamically favourable reaction, with the ΔrG°estimated from experimental data at 298 K to be -3.0 kcal mol-1. It proceeds in hydrocarbon solvents with a pseudo first-order rate constant of 6.4 × 10-6 s-1 and 7.4 × 10-5 s-1 in C6D12 and C6D6, respectively, at 20°C. This 1,3-hydrogen shift is formally forbidden by symmetry and has to occur by an alternative pathway. The proposed mechanism for buta-1,2-diene to but-2-yne isomerisation by (Me5C5)2Yb involves coordination of methylallene (buta-1,2-diene) to (Me5C5)2Yb, and deprotonation of methylallene by one of the Me5C5 ligands followed by protonation of the terminal methylallenyl carbon to yield the known coordination compound (Me5C5)2Yb(η2-MeCCMe). Computationally, this mechanism is not initiated by a single electron transfer step, and the ytterbium retains its oxidation state (II) throughout the reactivity. Experimentally, the influence of the metal centre is discussed by comparison with the reaction of (Me5C5)2Ca towards buta-1,2-diene, and (Me5C5)2Yb with ethylene. The mechanism by which the Me5C5 acts as a proton-relay within the coordination sphere of a metal also rationalises the reactivity of (i) (Me5C5)2Eu(OEt2) with phenylacetylene, (ii) (Me5C5)2Yb(OEt2) with phenylphosphine and (iii) (Me5C5)2U(NPh)2 with H2 to yield (Me5C5)2U(HNPh)2. In the latter case, the computed mechanism is the heterolytic activation of H2 by (Me5C5)2U(NPh)2 to yield (Me5C5)2U(H)(HNPh)(NPh), followed by a hydrogen transfer from uranium back to the imido nitrogen atom using one Me5C5 ligand as a proton-relay. The overall mechanism by which hydrogen shifts using a pentamethylcyclopentadienyl ligand as a proton-relay is named Carambole in reference to carom billiards.
- Kefalidis, Christos E.,Perrin, Lionel,Burns, Carol J.,Berg, David J.,Maron, Laurent,Andersen, Richard A.
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Read Online
- Process for preparation of phosphorane and phosphonyl compounds
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The invention relates to the field of new materials of fine chemicals, in particular to a new safe, convenient, mild, efficient, environment-friendly and economical preparation process technology of phosphorane and phosphonyl compounds.
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Paragraph 0023-0027; 0028-0030; 0034-0036
(2021/06/06)
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- One-pot synthesis of binaphthyl-based phosphines via direct modification of BINAP
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Herein reported is the convenient and efficient strategy for the preparation of binaphthyl-based phosphines through direct modification to the commercially available 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) with sodium. In the absence of 15-crown-5-ether, a cyclic sodium dinapthylphospholide intermediate is mainly generated. With 15-crown-5-ether, P-Ph bonds are selectively cleft by Na to produce binaphthyl-based disodium phosphides. The mechanism of selective formation of sodium dinapthylphospholide or binaphthyl-based disodium phosphides is proposed.
- Ye, Jing-Jing,Zhang, Jian-Qiu,Shimada, Shigeru,Han, Li-Biao
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supporting information
(2021/11/18)
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- Photocatalytic Arylation of P4 and PH3: Reaction Development Through Mechanistic Insight
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Detailed 31P{1H} NMR spectroscopic investigations provide deeper insight into the complex, multi-step mechanisms involved in the recently reported photocatalytic arylation of white phosphorus (P4). Specifically, these studies have identified a number of previously unrecognized side products, which arise from an unexpected non-innocent behavior of the commonly employed terminal reductant Et3N. The different rate of formation of these products explains discrepancies in the performance of the two most effective catalysts, [Ir(dtbbpy)(ppy)2][PF6] (dtbbpy=4,4′-di-tert-butyl-2,2′-bipyridine) and 3DPAFIPN. Inspired by the observation of PH3 as a minor intermediate, we have developed the first catalytic procedure for the arylation of this key industrial compound. Similar to P4 arylation, this method affords valuable triarylphosphines or tetraarylphosphonium salts depending on the steric profile of the aryl substituents.
- Cammarata, Jose,Gschwind, Ruth M.,Lennert, Ulrich,Rothfelder, Robin,Scott, Daniel J.,Streitferdt, Verena,Wolf, Robert,Zeitler, Kirsten
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supporting information
p. 24650 - 24658
(2021/10/14)
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- Oligodentate Phosphine Ligands with Phospholane End Groups: New Synthetic Access and Application to Molybdenum-Based Synthetic Nitrogen Fixation
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A new synthetic access to oligodentate phosphine ligands with phospholane end groups, starting from lithium phospholanide, is established. Based on this building block, the tridentate ligand prPP(Ph)P-pln was synthesized and used for the synthesis of [MoX3{prPP(Ph)P-pln}] (X = Cl, Br, I) precursors. Sodium amalgam reduction in the presence of N2 and either mono- or bidentate ligands leads to several molybdenum(0) mono- and bis(dinitrogen) complexes, respectively. With the diphosphine dppm a mixture of facial and meridional isomers of [Mo(N2){prPP(Ph)P-pln}(dppm)] is formed. Using the monophosphines PMePh2 and PMe2Ph mer-[Mo(N2){prPP(Ph)P-pln}(PMe2Ph)2] and trans-[Mo(N2)2{prPP(Ph)P-pln}(PMePh2)] could be obtained. The spectroscopic properties and reactivity of the latter towards protonation was investigated, and a hydrazido complex could be obtained and characterized.
- Pfeil, Mareike,Engesser, Tobias A.,Koch, Alexander,Junge, Jannik,Krahmer, Jan,N?ther, Christian,Tuczek, Felix
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p. 1437 - 1448
(2019/12/24)
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- Tailoring Phospholes for Imprint of Fluorescent 3D Structures
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PMMA based polymer blends have been infused with luminescent phospholes and have been structured via nanoimprint. While symmetrically substituted phospholes are prone to crystallization and phase separation, structural modification of the phosphole backbone in the α- and β-positions has been explored, which prevents these issues; a structural explanation for this is suggested. Best phase integrity has been obtained for β-silyl-substituted phospholes, which were implemented in thin films and beads. The emission wavelengths of the phospholes are shifted bathochromically in the polymer matrix as compared to the neat compounds featuring emission bands near 500 nm. This enables tracking of the fluorescent beads using standard fluorescence microscopy.
- Roesler, Fabian,Kaban, Burhan,Klintuch, Dieter,Ha, Uh-Myong,Bruhn, Clemens,Hillmer, Hartmut,Pietschnig, Rudolf
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p. 4820 - 4825
(2019/11/26)
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- Carbonyl and olefin hydrosilylation mediated by an air-stable phosphorus(iii) dication under mild conditions
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The readily-accessible, air-stable Lewis acid [(terpy)PPh][B(C6F5)4]21 is shown to mediate the hydrosilylation of aldehydes, ketones, and olefins. The utility and mechanism of these hydrosilylations are considered.
- Andrews, Ryan J.,Chitnis, Saurabh S.,Stephan, Douglas W.
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supporting information
p. 5599 - 5602
(2019/05/21)
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- Exploring the Reactivity of Donor-Stabilized Phosphenium Cations: Lewis Acid-Catalyzed Reduction of Chlorophosphanes by Silanes
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Phosphane-stabilized phosphenium cations react with silanes to effect either reduction to primary or secondary phosphanes, or formation of P-P bonded species depending upon counteranion. This operates for in situ generated phosphenium cations, allowing catalytic reduction of P(III)-Cl bonds in the absence of strong reducing agents. Anion and substituent dependence studies have allowed insight into the competing mechanisms involved.
- Pearce, Kyle G.,Borys, Andryj M.,Clark, Ewan R.,Shepherd, Helena J.
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supporting information
p. 11530 - 11536
(2018/09/21)
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- Copper-Phosphido Intermediates in Cu(IPr)-Catalyzed Synthesis of 1-Phosphapyracenes via Tandem Alkylation/Arylation of Primary Phosphines
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Tandem alkylation/arylation of primary phosphines PH2R (R = Ph, Cy, Fc, FcCH2; Fc = ferrocenyl) with 5-bromo-6-chloromethylacenaphthene (1) and 2 equiv of NaOSiMe3 using the catalyst precursor Cu(IPr)(Cl) gave a series of 1-phosphapyracenes (R-PyraPhos, 2a-d), which were isolated as borane adducts 3a-d. Similar reactions of the chiral air-stable primary phosphines PH2Ar? (Ar? = (S)-binaphthyl (4), (R)-MeO-binaphthyl (5)) to yield 2e,f and 3e,f were diastereoselective (dr = 2:1 and 1.2:1, respectively), and chromatography gave a highly enriched sample of one diastereomer of 3f. The mechanism of catalysis was investigated by NMR monitoring and independent syntheses of potential intermediates. The phosphido complexes Cu(IPr)(PHAr′) (Ar′ = Ph, (R)-MeO-binaphthyl) were generated in equilibrium mixtures, along with Me3SiOH, from Cu(IPr)(OSiMe3) and PH2Ar′. They reacted with benzyl chloride 1 to yield Cu(IPr)(Cl) and the secondary phosphines PHAr′(CH2Ar) (Ar = Br-acenaphthyl); addition of NaOSiMe3 yielded PyraPhos derivatives 2a,f. Deprotonation of the cations [Cu(IPr)(PHAr′CH2Ar)][OTf] (Ar′ = Ph, (R)-MeO-binaphthyl) was investigated as a route to the secondary phosphido complexes Cu(IPr)(PAr′CH2Ar) (13). We propose that C-Br oxidative addition in the Cu(I)-phosphido intermediates 13 followed by P-C reductive elimination from Cu(III)-phosphido complexes forms the PyraPhos ring, with diastereoselection arising from rapid pyramidal inversion of Cu-phosphido groups.
- Wang, Ge,Gibbons, Sarah K.,Glueck, David S.,Sibbald, Connor,Fleming, James T.,Higham, Lee J.,Rheingold, Arnold L.
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p. 1760 - 1772
(2018/06/18)
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- A Universally Applicable Methodology for the Gram-Scale Synthesis of Primary, Secondary, and Tertiary Phosphines
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Although organophosphine syntheses have been known for the better part of a century, the synthesis of phosphines still represents an arduous task for even veteran synthetic chemists. Phosphines as a class of compounds vary greatly in their air sensitivity, and the misconception that it is trivial or even easy for a novice chemist to attempt a seemingly straightforward synthesis can have disastrous results. To simplify the task, we have previously developed a methodology that uses benchtop intermediates to access a wide variety of phosphine oxides (an immediate precursor to phosphines). This synthetic approach saves the air-free handling until the last step (reduction to and isolation of the phosphine). Presented herein is a complete general procedure for the facile reduction of phosphonates, phosphinates, and phosphine oxides to primary, secondary, and tertiary phosphines using aluminum hydride reducing agents. The electrophilic reducing agents (iBu)2AlH and AlH3 were determined to be vastly superior to LiAlH4 for reduction selectivity and reactivity. Notably, it was determined that AlH3 is capable of reducing the exceptionally resistant tricyclohexylphosphine oxide, even though LiAlH4 and (iBu)2AlH were not. Using this new procedure, gram-scale reactions to synthesize a representative range of primary, secondary, and tertiary phosphines (including volatile phosphines) were achieved reproducibly with excellent yields and unmatched purity without the need for a purification step.
- Rinehart, N. Ian,Kendall, Alexander J.,Tyler, David R.
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supporting information
p. 182 - 190
(2018/02/06)
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- 3-Phenylphosphaprolines – Synthesis, structure and properties of heterocyclic α-phosphanyl amino acids
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“Phenylphosphaprolines”, containing trivalent phosphorus within the five-membered ring of proline, were synthesized by cyclocondensation of 2-phenylphosphanyl ethylamines 1a,b with equimolar amounts of glyoxylic acid hydrate (GAH) or pyruvic acid in diethyl ether or 1,4-dioxane. Reaction monitoring revealed primary formation of acyclic intermediates that then converted more (1a) or less (1b) rapidly to the phosphanyl amino acids cis/trans-2a,b or cis/trans-4a,b. Ammonium-ethylphosphonium-bis(glycolate) impurities, e.g. 3b, were formed when an excess of GAH was applied. The conversion of 1a with phenylformic acid via the acyclic precursors 5a and 6a to the heterocyclic product cis/trans-7a was very slow, whereas heating of the mixture in 1,4-dioxane proceeded with decarboxylation to cis/trans-8a. The structures and diastereoisomer ratios of all new compounds were determined by 1H, 31P and 13C solution NMR spectra. The cis/trans-ratio of 2a depends on the synthetic route, i.e. addition of the phosphanylethyl amine 1a to GAH (acidic medium) or of GAH to 1a (basic medium). Furthermore, this ratio changed slowly during storage of the solution of 2a in CD3OD or methanol, indicating ring-opening ring-closure reactions and lower kinetic stability than for proline. XRD analyses established the structures of trans-2a and likewise of trans-4a and trans-8a, which from concentrated solutions crystallized in pure form.
- Basvani, Kaleswara R.,Kindermann, Markus K.,Frauendorf, Holm,Schulzke, Carola,Jones, Peter G.,Heinicke, Joachim W.
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supporting information
p. 195 - 204
(2017/05/09)
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- benzyl pair (2, 4, 6-trimethyl benzoyl) phosphine oxide of the preparation method
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The invention discloses a preparation method of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide as an efficient free radical photoinitiator. The preparation method of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide comprises the concrete steps of with 2,4,6-trimethylbenzaldehyde as a raw material, enabling 2,4,6-trimethylbenzaldehyde and phenylphosphine oxide to be subjected to condensation reaction in the existence of a catalyst, and then, carrying out oxidation reaction. Extraction and solvent replacement are not needed and continuous reaction can be realized in the reaction process. The preparation method of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, disclosed by the invention, is low in price, environment-friendly, easy to operate and suitable for realizing industrialization.
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Paragraph 0034; 0035
(2016/11/21)
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- Preparing method for acyl phosphate (oxide) or sulfonyl phosphate (oxide) compound
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The invention relates to the technical field of novel radiation-cured photo-polymerization materials, in particular to a synthesizing method for an acyl phosphate or acyl phosphate oxide (sulfur) or sulfonyl phosphate oxide (sulfur) photo-polymerization initiator of the structure shown in the formula (I) in the description.
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Paragraph 0060; 0061
(2017/01/02)
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- Preparation method of acyl phosphine (oxygen) or sulfonyl phosphine (oxygen) compounds
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The invention relates to the technical field of radiation-cured photo-polymerized novel materials and especially relates to synthesis methods for a photo-polymerization initiator in the types of acyl phosphine, acyl phosphine oxygen (sulfur) or sulfonyl phosphine oxygen (sulfur) represented as the formula (I).
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Paragraph 0060; 0061
(2018/02/04)
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- Synthesis, structure and spectroscopic properties of 2,3- bis(diphenylphosphino)quinoxaline (dppQx) and its copper(I) complexes
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Phosphinoquinoxalines were prepared by treatment of 2,3-dichloroquinoxaline (3) with phosphorus nucleophiles. The Arbuzov reaction of 3 with PPh(O-i-Pr)2 gave a mixture of diastereomers of 2,3-(PPh(O)(O-i-Pr)) 2quinoxaline (6); the crystal structure of rac-6 was determined, but attempts at reduction to yield bis(phenylphosphino)quinoxaline 7 resulted in P-C cleavage and formation of phenylphosphine. The bis(secondary phosphine) 7 could be generated from 3 and LiPHPh(BH3), but was not isolated in pure form. Copper-catalyzed coupling of PHPh2 with 3 gave 2,3-bis(diphenylphosphino)quinoxaline (4, dppQx), whose coordination chemistry was investigated, with comparison to data for the analogous 1,2- bis(diphenylphosphino)benzene (dppBz) complexes. Reaction of dppQx with [Cu(NCMe)4][PF6] gave [Cu(dppQx)2][PF 6] (8); CuCl yielded [Cu(dppQx)Cl]2 (9). Reaction of [Cu(NCMe)4][PF6] with one equiv of DPEphos, followed by one equiv of dppQx, gave [Cu(dppQx)(DPEphos)][PF6] (10). Ligand 4 and copper complexes 8 and 9 were crystallographically characterized. The UV-Vis spectra of dppQx and its copper complexes were red-shifted from those of the dppBz analogs; in contrast to results for the dppBz complexes, those of dppQx were not luminescent in solution.
- Cain, Matthew F.,Reynolds, Samantha C.,Anderson, Brian J.,Glueck, David S.,Golen, James A.,Moore, Curtis E.,Rheingold, Arnold L.
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experimental part
p. 55 - 61
(2011/06/24)
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- Single-step synthesis of secondary phosphine oxides
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We report that in the presence of trifluoroacetic acid primary phosphines undergo efficient addition to aldehydes to form the corresponding secondary phosphine oxides in 47-97% yield. This transformation is compatible with aryl and alkyl phosphines, as well as a broad range of aldehydes, including formaldehyde. By using 1,5-dialdehydes as reaction partners, the addition provides a straightforward route to bis(phosphine oxides), which are difficult to prepare by alternative methods. In the presence of boron trifluoride diethyl etherate as reagent, benzophenone was shown to couple to phenylphosphine and cyclohexylphosphine in 92% and 72% yield, respectively. Twenty-three examples are presented.
- Bloomfield, Aaron J.,Qian, Jack M.,Herzon, Seth B.
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body text
p. 4193 - 4195
(2010/12/19)
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- P-phenyl-2,2,6,6-tetramethylphosphorinan-4-ol: An air-stable p,o-type ligand for palladium-mediated cross-coupling reactions
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A two-step entry to a chemically robust, hindered P,O-type phosphorinane-based ligand and its application toward Pd-mediated cross-coupling reactions of unactivated aryl chlorides is presented. A two-step entry to a chemically robust, hindered P,O-type phosphorinane-based ligand and its application toward Pd-mediated cross-coupling reactions of unactivated aryl chlorides is presented. Copyright
- Ullah, Ehsan,McNulty, James,Larichev, Vladimir,Robertson, Al J.
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experimental part
p. 6824 - 6830
(2011/03/19)
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- The Ever-surprising chemistry of boron: Enhanced acidity of phosphine·boranes
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The gas-phase acidity of a series of phosphines and their corresponding phosphine·borane derivatives was measured by FT-ICR techniques. BH 3 attachment leads to a substantial increase of the intrinsic acidity of the system (from 80 to 110 kJ mol-1). This acidity-enhancing effect of BH3 is enormous, between 13 and 18 orders of magnitude in terms of ionization constants. This indicates that the enhancement of the acidity of protic acids by Lewis acids usually observed in solution also occurs in the gas phase. High- level DFT calculations reveal that this acidity enhancement is essentially due to stronger stabilization of the anion with respect to the neutral species on BH3 association, due to a stronger electron donor ability of P in the anion and better dispersion of the negative charge in the system when the BH3 group is present. Our study also shows that deprotonation of ClCH2PH2 and ClCH 2PH2·BH3 is followed by chloride departure. For the latter compound deprotonation at the BH3 group is found to be more favorable than PH2 deprotonation, and the subsequent loss of Cl- is kinetically favored with respect to loss of Cl - in a typical SN2 process. Hence, ClCH2PH 2·BH3 is the only phosphine·borane adduct included in this study which behaves as a boron acid rather than as a phosphorus acid.
- Hurtado, Marcela,Yanez, Manuel,Herrero, Rebeca,Guerrero, Andres,Juan Z. Davalos,Jose-Luis, M. Abboud,Khater, Brahim,Guillemin, Jean-Claude
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supporting information; experimental part
p. 4622 - 4629
(2009/12/29)
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- A simple straightforward synthesis of phenylphosphane and the photoinitiator bis(mesitoyl)phenylphosphane oxide (IRGACURE 819)
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A straightforward high-yield synthesis for the photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphane oxide (16, IRGACURE 819) involves: i) the reaction of phenyldichlorophosphane, PhPCl2, with sodium to give [Na2(P2Ph2)(tmeda)]6 (5); ii) protonation of 5 with tert-butanol to give 1,2-diphenyldiphosphane, PhHP-PHPh (12); iii) reduction of 12 by sodium to yield [Na(PHPh)x (13); iv) protonation of 13 with tert-butanol to give phenylphosphane PhPH2 (14) in excellent yields; v) reaction of 14 with 2,4,6-trimethylbenzoylchloride (MesCOCI) in presence of the NaOt-Bu formed in steps ii and iv to give bis(2,4,6-trimethylbenzoyl)phenylphosphane 7; vi) oxygenation of 7 with 30% aqueous hydrogen peroxide to give the final product 16. This reaction can be performed in toluene with about 4 vol-% of tmeda as an activator in a one-pot synthesis without changing the solvent. The structures determined by X-ray diffraction of the unique hexameric aggregate 5 and 16 are reported. Schweizerische Chemische Gesellschaft.
- Gruetzmacher, Hansjoerg,Geier, Jens,Stein, Daniel,Ott, Timo,Schoenberg, Hartmut,Sommerlade, Reinhard H.,Boulmaaz, Souad,Wolf, Jean-Pierre,Murer, Peter,Ulrich, Thomas
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- Electrocatalytic reduction of aryldichlorophosphines with the (2,2′-bipyridine)nickel complexes
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The reduction of aryldichlorophosphines in organic solvents was studied by cyclic voltammetry, preparative electrolysis, and chemical reduction. The reaction of the electrochemically generated (2,2′-bipyridine)nickel(0) complexes with aryldichlorophosphines PhPCl2 and tippPCl2 (tipp is 2,4,6-triisopropylphenyl) proceeds through the formation of highly reactive organophosphorus intermediates, whose reactions with diphenylacetylene and hex-1-ene afford phosphirene and phosphirane heterocycles, respectively.
- Yakhvarov,Hey-Hawkins,Kagirov,Budnikova,Ganushevich,Sinyashin
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p. 935 - 942
(2008/09/17)
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- PROCESS FOR PREPARING ACYLPHOSPHANES AND THEIR OXIDES AND SULPHIDES
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A process for the preparation of bis-acylphosphanes of formula R1P(COR2)2 wherein R1 is unsubstituted phenyl or phenyl substituted by one to five halogen, C1-C8-alkyl, C1-C8-alkylthio and/or C1-C8-alkoxy; R2 is C1-C18-alkyl or C2-C18-alkenyl ; C1C18-alkyl or C2-C18-alkenyl substituted once or more than once by halogen -OR10, -OCO-R10, -OCO-Hal, -COO-R10, -N(R11)-CO-R10, -N(R11)-CO-Hal, -CO-NR11R10, -CH=CH-CO-OR10 or -CH=CH-phenyl; -C(C1-C4alkyl)=C(C1-C4alkyl)-CO-OR10 or -C(C1-C4alkyl)=C(C1-C4alkyl)-phenyl; C5-C12cycloalkyl, C2-C18alkenyl, phenyl-C1-C4alkyl, phenyl, naphthyl, biphenyl or a 5- or 6-membered -0-, S- or N-containing heterocyclic ring, the radicals phenyl, naphthyl, biphenyl or the 5- or 6-membered -0-, S- or N-containing heterocyclic ring being unsubstituted or substituted by one to five halogen, C1-C8alkyl, C1-C8alkoxy and/or C1-C8alkylthio; the process comprises the steps in a) selective reduction of dichlorophenylphosphanes of the formula R1P(CI)2 by means of hydrogen at a temperature in the range from 20 to 200°C and under hydrogen pressure of atmospheric pressure to 20bar in the presence of a hydrogenation catalyst, a tert. aliphatic amine or an aromatic amine and in the presence of a non protic solvent which is unreactive under the hydrogenation conditions to obtain cyclic phenylphosphanes (R1P)n (n = 4 to 6); or b) selective reduction of R1P(CI)2 by means of hydrogen at a temperature in the range from 80 to 25O°C and under hydrogen pressure of 25 to 250bar in the presence of a hydrogenation catalyst, a tert. aliphatic amine or an aromatic amine and in the presence of a non protic solvent which is unreactive under the hydrogenation conditions to obtain R1PH2; c) subsequent reaction with an acid halide of formula in the presence of an apropriate base R2COHal wherein R2 is as defined above.
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Page/Page column 9-10
(2008/06/13)
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- Electrocatalytic eco-efficient functionalization of white phosphorus
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The novel eco-efficient methods to transform white phosphorus into the esters of phosphoric, phosphorous and phosphonic acids, tertiary phosphines and other organophosphorus compounds under conditions of electrochemical catalysis were elaborated. The mechanism of these processes was investigated using the method of cyclic voltammetry and preparative electrolysis.
- Budnikova, Yulia H.,Yakhvarov, Dmitry G.,Sinyashin, Oleg G.
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p. 2416 - 2425
(2007/10/03)
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- Reactivity of electron-poor decamethyl-1,3-diboraruthenocene with sulfur and phosphorus compoundsDedicated to Professor Bernt Krebs on the occasion of his 65th birthday
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Decamethyl-1,3-diboraruthenocene [(η5-C5 Me5)Ru{η5-(CMe)3(BMe)2}] (1) reacts with cyclo-octasulfur in hexane to give [(η5 -C5Me5){η5-(CMe)3 (BMe)2}Ru=S] (3), which may also be obtained from 1 and propylene sulfide. 1 reacts with H2S to form the ruthenathiacarboranyl complex [(η5-C5 Me5)Ru{η4-(CMe)3(BMe)2S}] (6), for which a nido-structure is proposed. The isomeric compounds 3 and 6 have different stabilities: 3 loses sulfur and unexpectedly the closo-cluster [(η5-C5Me5) 2Ru2H(CMe)3(BMe)2] (4) is formed with hydrogen bridging the basal and apical Ru centers. Reaction of 1 with carbonylsulfide (COS) yields the dinuclear ruthenium compound [(η5-C5Me5)Ru{η5 -(CMe)3(BMe)2(S)(COBMe)}]2 (7) in which two B-O groups bridge two ruthenium complexes. Its formation results from a complex reaction sequence: sulfur inserts into the diborolyl ring and the ligand CO forms an oxygen-boron bridge to a second molecule, followed by insertion of the carbonyl carbon into the double bond of the diboraheterocycle. Carbon disulfide reacts with 1 to give the dinuclear complex 8 with two CS2 molecules connecting the ruthenium centers. When 1 and P4 are heated in toluene, the sandwich 9 is obtained by formal i nsertion of a P-H group into the diborolyl ring of 1 and the triple-decker [{η5-(C5Me5)Ru }2{μ-(MeC)3P(MeB)2} (10) is detected in the mass spectrum. The phosphaalkyne P≡CtBu inserts into 1 to give the ruthenaphosphacarborane [(η5 -C5Me5)Ru{(CMe)2(BMe)(PC t Bu)(CMe) (BMe)}] (11) in high yield. Phosphanes react with 1 to give weak donor-acceptor complexes 1 · PH2R (12) (R=Ph, H). The compositions of the compounds are deduced from spectroscopic and analytical data and are confirmed for 4 and 7 by X-ray structural analyses.
- Bach, Bettina,Nie, Yong,Pritzkow, Hans,Siebert, Walter
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p. 429 - 437
(2007/10/03)
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- Novel phosphine compound, transition metal complex containing the same phosphine compound as ligand and asymmetric synthesis catalyst containing the complex
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A phosphine compound of formula (1) and a phosphine compound of formula (2) a transition metal complex having the phosphine compound as a ligand and a catalyst for asymmetric hydrogenation including the transition metal complex.
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- The influence of the sacrificial anode nature on the mechanism of electrochemical arylation and alkylation of white phosphorus
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The material of the sacrificial anode has a substantial effect on the nature and yield of the target products of electrochemical phosphorylation of organic halides by white phosphorus in the presence of the nickel complexes with 2,2′-bipyridine. The use of the zinc anode results in the products with tricoordinated phosphorus, viz., triorganylphosphines, the reaction on the aluminum anode affords triorganylphosphine oxides, and the presence of Mg 2+ ions in the reaction mixture provides the transformation of white phosphorus into cyclic phosphines (PhP)5.
- Yakhvarov,Budnikova,Tazeev,Sinyashin
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p. 2059 - 2064
(2007/10/03)
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- B(C6F5)3-catalyzed silylation versus reduction of phosphonic and phosphinic esters with hydrosilanes
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HSiR3/cat-B(C6F)3 induced dealkylation or reduction of esters of phosphorus at 20°C. A specific conversion to silylesters occurred by reaction with tertiary silanes. In contrast, free phosphines were observed in the reaction with mono- or disubstituted silanes. A mechanism was proposed to rationalize these results.
- Denis, Jean-Marc,Forintos, Henrietta,Szelke, Helga,Keglevich, Gy?rgy
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p. 5569 - 5571
(2007/10/03)
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- Reaction of dichlorophosphines with glycidol. New data on the transformations of cyclic phosphonates
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Reaction of dichlorophosphines with glycidol yields 2-R-4-chloromethyl-1,3,2-dioxaphospholanes as primary products, which under the reaction conditions or under the action of HC1 surprisingly readily undergo redox transformations yielding 2-R-4-chloromethyl-1,3,2-dioxaphospholane 2-oxides, dichloropropyl R-phosphinates, bis(dichloropropyl) R-phosphonates, and phosphines RPH2.
- Bredikhin,Lazarev,Efremov,Sharafutdinova,Bredikhina
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p. 708 - 713
(2007/10/03)
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- New phosphine ligands with the OPN donor configuration
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New, functionalised phosphines with an OPN donor set which are potentially capable of square planar co-ordination were synthesized by stepwise introduction of the oxygen and nitrogen functional substituents to phosphorus. The secondary phosphines (phenyl)(tetrahydrofurfuryl)phosphine, 1, and [2-(l, 3-dioxolan-2-yl)ethyl](phenyl)phosphine, 2, were first prepared before the introduction of the nitrogen donor substituents. The OPN phosphines (phenyl)(D')(D2)phosphine {D1 = tetrahydrofurfuryl, D2 = 2-pyridylmethyl or pyridyl; D1 = 2-(l, 3-dioxolan-2-yl)ethyI, D2 = 2-pyridylmethyl}, 3-5, were obtained. This approach was not appropriate for the preparation of an OPN ligand with an ester functionality. Therefore the synthesis of methyl 3-[(phenyl)(2-pyridylmethyl)phosphino]propanoate, 7, was achieved via a radical induced coupling of methyl acrylate to (phenyl)(2-pyridylmethyl)phosphine 6. All new ligands, 1-5, 7, were characterised by 'H, "C and 3IP NMR spectroscopy. The methods developed allowed the ligands to be synthesized in high yields and purity such that further purification was generally unnecessary for subsequent applications. The Royal Society of Chemistry 2000.
- Green, Melinda J.,Cavell, Kingsley J.,Edwards, Peter G.
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p. 853 - 858
(2007/10/03)
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- Ylidylphosphanes and -diphosphanes
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Chlorophosphanyl and dichlorophosphanyl alkylidene- and benzylidenephosphoranes 6 and 8 are converted by reaction with LiAlH4 to the respective phosphanes 7 and 9. The former can be isolated, but decompose on heating or on protonation to give the ylidyl diphosphane 11 and the phosphonium ylide or phosphonium salt, respectively. The final products are the cyclooligophosphanes 15-17. Only the C-tert-butyl derivative 7c is stable in both regards. The conformation of the RPH group in 7 as compared to that of the RPCl group in 6 clearly reflects their different interaction with the ylide moiety.
- Breitsameter, Florian,Schmidpeter, Alfred,Schier, Annette
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p. 381 - 388
(2007/10/03)
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- Coordination Catalysis in Organic Electrosynthesis. Electrochemical Phosphorylation of Organic Halides in the Presence of Samarium Dichloride
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The feasibility was demonstrated for arylation (or alkylation) of white phosphorus under the action of electrochemically generated Sm(II).
- Budnikova,Yakhvarov,Kargin
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p. 566 - 569
(2007/10/03)
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- P-H bond activation of primary phosphine-boranes: Access to α-hydroxy and α,α′-dihydroxyphosphine-borane adducts by uncatalyzed hydrophosphination of carbonyl derivatives
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Primary P-phenyl and P-methyl phosphine-boranes 1 and 2 are prepared by complexation of the free phosphines with BH3 · SMe2. They are stable and can be purified by distillation. Under basic conditions, they lead selectively to secondary alkylphosphine-boranes and under neutral conditions to the corresponding mono- and bis-hydroxyphosphine-boranes 5 and 6. All these new compounds are purified by chromatography on silica gel. A competitive hydroboration induced by the decomplexation of BH3 is observed as a minor process. Conditions for the decomplexation of phosphine-borane adducts are presented.
- Bourumeau, Karine,Gaumont, Annie-Claude,Denis, Jean-Marc
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p. 205 - 213
(2007/10/03)
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- Wasserloesliche Phosphane. II. Ein neuer Syntheseweg fuer wasserloesliche sekundaere und tertiaere Phosphane mit sulfonierten aromatischen Resten - Kristallstruktur von P(p-C6H4-SO3K)3*KCl*0.5H2O
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Water soluble tertiary phosphanes 2, 7, 10-17 with sulfonated aromatic substituents p-C6H4-SO3K and 2,4-C6H3(SO3K)2 can be obtained in good yields by nucleophilic aromatic substitution of fluorine in p-F-C6H4-SO3K (1) or F-C6H3-2,4-(SO3K)2 (5) with PH3 or primary and secondary phosphanes in the superbasic medium dimethyl sulfoxide (DMSO)/KOH(solid).The first water-soluble secondary phosphane HP2 (6) having sulfonated aromatic substituents can be obtained if 5 is reacted under similar conditions with PH3.Highly sulfonated phosphanes (7-9) with remarkable solubilities in water are formed upon reaction of 6 with F-C6H5, n-BuBr or C6H5-CH2-Br, respectively, in the superbasic medium.The resulting compounds have been identified by their 1H, 13C and 31P NMR spectra.X-Ray structural analysis of P(p-C6H4-SO3K)3*KCl*0.5H2O shows C3 symmetry for the trianion of 2 with the P-C-P bond angles (103.5(2)o) and P-C bond lengths (1.843(4) Angstroem) being almost identical to those in Ph3P.Key words: Phosphine; Catalysis; Nuclear magnetic resonance; Water soluble phosphine; Phase transfer; Hydroformylation
- Herd, Oliver,Hessler, Antonella,Langhans, Klaus P.,Stelzer, Othmar,Sheldrick, William S.,Weferling, Norbert
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- Enantioselective Catalysis, VIII. - New 1,2-Bisphosphane Ligands with Four Stereogenic Centers and Additional Methoxy Groups for Asymmetric Catalytic Hydrogenation
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The synthesis of N-acyl derivatives of all possible diastereomers of -3,4-bispyrrolidine and -3,4-bispyrrolidine in optical pure form is described.Palladium and rhodium complexes with these ligands were prepared.The enantioselective hydrogenation of acetamidocinnamic acid with these rhodium complexes was studied at H2 pressures between 1 and 75 bar.There is only a small influence of the 2-methoxy group in the ligand on the catalytic hydrogenation when compared with the respective unsubstituted diastereomer.Te structure of pyrrolidine-P,P'>diiodopalladium was determined by X-ray diffraction.Key Words: 3,4-Bis(phosphanyl)pyrrolidines / Palladium complexes / Rhodium complexes / Asymmetric hydrogenation
- Nagel, Ulrich,Bublewitz, Alexander
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p. 1061 - 1072
(2007/10/02)
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- Thermal and photochemical transformations of organoiridium phosphide complexes. Mechanistic studies on carbon-phosphorus bond formation to generate cyclometalated hydride complexes by α-hydride abstraction
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The thermal and photolytic transformations of a series of methyliridium(III) phosphide complexes are described. Complexes of the formula Ir(CH3)PR2[N(SiMe2CH2PPh 2)2] (R = Ph, Me) rearrange thermally to generate the corresponding cyclometalated derivatives fac-Ir(η2-CH2PR2)H[N(SiMe 2CH2PPh2)2]; continued thermolysis results in the formation of the iridium(I) phosphine complexes Ir(PMeR2)[N(SiMe2CH2PPh2) 2]. Under photolytic conditions the phosphide derivatives rearrange directly to the phosphine complexes with no observable intermediates. The phenylphosphide complex Ir(CH3)PHPh[N(SiMe2CH2PPh2) 2] rearranges directly to the phosphine derivative Ir(PHPhMe)[N(SiMe2CH2PPh2)2] both thermally and photolytically with no observable intermediates. Crystals of Ir(CH3)PPh2[N(SiMe2CH2PPh 2)2] are monoclinic with a = 13.506 (3) A?, b = 13.665 (3) A?, c = 22.816 (7) A?, β= 92.35 (2)°, Z = 4, Dc = 1.454 g cm-3, and space group P21/c. The structure was solved by the Patterson method and refined by full-matrix least-squares procedures to R = 0.034 and Rw = 0.037 for 3993 reflections with I ≥ 3σ(I). Crystals of fac-Ir(η2-CH2PPh2)H[N(SiMe 2CH2PPh2)2] are monoclinic with a = 9.253 (2) A, b = 21.950 (5) A?, c = 20.081 (4) A?, β= 90.74 (2)°, Z = 4, Dc = 1.50 g cm-3, and space group P21/c. The structure was solved by conventional heavy-atom techniques and was refined in blocks (with the Ir atom in every cycle) by using least-squares procedures down to R = 0.0356 and Rw = 0.0370 for 4448 reflections with I ≥ 3σ(I). Mechanistic studies showed that the formation of the cyclometalated hydride does not involve reductive transfer of the methyl and the phosphide ligands to form a phosphine complex followed by intramolecular C-H bond activation, rather C-H bond abstraction occurs first followed then by C-P bond formation. Transition-state arguments are used to rationalize the difference in the reactivity of the phenylphosphide complex for which no cyclometalated intermediate was detected.
- Fryzuk, Michael D.,Joshi, Kiran,Chadha, Raj K.,Rettig, Steven J.
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p. 8724 - 8736
(2007/10/02)
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- STRUTURAL CHARACTERIZATION OF 1,2,4,5-TETRAPHENYLCYCLO-3,6-DICARBA-1,2,4,5-TERAPHOSPHINE: A HIGHLY FOLDED CHAIR CONFORMATION
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The title compound crystallyzed in the monoclynic space group P21/c, with the followingunit cell parameters: a = 11.235(8), b = 8.473(2), c = 26.136(10) Aengstroem, β = 102.07(5) grad, V = 2432(3) Aengstroem3, Z = 4.1657 unique data were used to solve (direct methods) and refine the structure to give R = 0.126 and Rw = 0.118.The six-membered ring system is in a highly folded chair conformation with the phenyl group substituents on the phosphorous atoms oriented in the equatorial positions.The dihedral angles of the P-CH2-P plane with the P4 basal plane is a remarkable 101.8 grad (avarage).This dihedral angle is the closestto perpendicular ever observed for a monocyclic ring system.
- Laneman, Scott A.,Fronczek, Frank R.,Stanley, George G.
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- Organosubstituted 2,5-Dihydro-1,2,5-phosphasilaboroles - Preparation, Characterization, and Transformations
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The dimeric 4,5-diethyl-2,5-dihydro-2,2-dimethyl-3-organo-1-phenyl-1,2,5-phosphasilaboroles are prepared in yields of 70-80percent from the acylic (Z)-2-boryl-1-silylethene derivatives ClB(C2H5)C(C2H5)=CRSi(CH3)2Cl with Li2PC6H5.The solid (1a)2 is the trans isomer with a (PB)2 ring (X-ray analysis). (1a)2 forms the solid γ-Pic-1a with γ-picoline (γ-Pic), with trimethylphosphane (TMP) the easily dissociating TMP-1a. trans-Bis(4,5-diethyl-1,2,5,6-tetrahydro-2,2,3-trimethyl-1-phenyl-1,2,5-phosphasilaborin) (2a)2 (X-ray analysis) is obtained by methylene migration from (1a)2 and methylenetriphenylphosphorane (MTPP). (1a)2 reacts with trimethylamine N-oxide (TMANO) by C6H5P/O-exchange to form (3a) and (3'a), whereas (1a)2 and γ-picoline N-oxide (PNO) give γ-Pic-3a and (C6H5P)n (4; 4', 4'': n = 4-6). (1a)2 and electrophiles react to 1:1 addition compounds (1a-AlCl3; 1a-MeI).The crystalline (5a)2 is prepared by B/Al exchange from (1a)2 and 2. (1a)2 reacts with methanol by ring opening to give the (Z)-2-boryl-1-silylethene derivative CH3OB(C2H5)C(C2H5)=C(CH3)Si(CH3)2OCH3 (6a) and phenylphosphane (7) in high yield. (1a)2 and acetylacetone undergo C6H5P/O exchange giving a mixture of 3a and (Z/E)-4-(phenylphosphino)-3-penten-2-one (8). - The 11B-, 13C-, 29Si-, 31P-NMR data of the dimeric C2SiPB and C2SiPCB rings are compared and discussed together with the data of the unsaturated C2SiElB rings .
- Koester, Roland,Seidel, Guenter,Mueller, Gerhard,Boese, Roland,Wrackmeyer, Bernd
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p. 1381 - 1392
(2007/10/02)
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- Linear Oligophosphaalkanes, XIX. - Partial Alkylation of Phenylphosphane with Dihalomethanes CH2X2 (X = Cl, Br) - A Facile Synthesis of Methylenebis(phenylphosphane), HPhP-CH2-PPhH
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The reaction of PhPHNa with CH2X2 (X = Cl, Br) in tetrahydrofuran affords methylenebis(phenylphosphane), HPhP-CH2-PPhH (2), phenylphosphane, methylphenylphosphane, PhPHMe, and 1,2,3,4-tetraphenylcyclo-5-carba-1,2,3,4-tetraphosphane, CH2(PPh)4 (3).HPhP-CH2-PPhH (2) may be obtained in a facile one-step synthesis with yields up to 70percent by reaction of PhPH2 with CH2Cl2 and KOH in dimethyl sulfoxide/H2O or dimethylformamide/H2O.The formation of PhPHMe and CH2-(PPh4)4 may be explained by a reaction scheme including P-phenylphosphaalkene PhP=CH2 and HPhP-CH2Cl as reactive intermediates.The reactions between PhPHM (M = Na, K) and CH2Cl2 or CH2Br2 respectively, have been studied by independent experiments.
- Langhans, Klaus P.,Stelzer, Othmar
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p. 1707 - 1712
(2007/10/02)
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- PHOTOCHEMICAL REACTIONS OF PHOSPHAALKENES
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Photolysis of phosphaalkenes leads to an inversion of polarity of the phosphorus carbon double bond and to a cleavage into transient phosphinidene and carbene; unexpected alcoholysis of a PIII-C bond and the cycloaddition of a linear phosphaalkene on a diene are also reported.
- Meriem, Abdelkader,Majoral, Jean-Pierre,Revel, Monique,Navech, Jacques
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p. 1975 - 1978
(2007/10/02)
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