- Zwitterionic Design Principle of Nickel(II) Catalysts for Carbonylative Polymerization of Cyclic Ethers
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Zwitterionic structure is necessary for NiII complexes to catalyze carbonylative polymerization (COP) of cyclic ethers. The cationic charge at the NiII center imparts sufficient electrophilicity to the Ni–acyl bond for it to react wi
- Dai, Yiwei,He, Shiyu,Peng, Bangan,Crandall, Laura A.,Schrage, Briana R.,Ziegler, Christopher J.,Jia, Li
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- Synthesis method of polyketone ligand
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The invention provides a synthesis method of a polyketone ligand 3, 3-bis-[bis-(2-methoxyphenyl) phosphinomethyl]-1, 5-dioxa-spiro [5, 5] undecane, which comprises the following steps: a) carrying out reaction on anisole and diethyl phosphite in a solvent to obtain bis (2-methoxyphenyl) phosphine oxide; b) carrying out reduction reaction on the bis (2-methoxyphenyl) phosphine oxide obtained in the step a) in a solvent to obtain bis (2-methoxyphenyl) phosphine hydrogen; and c) reacting the bis (2-methoxyphenyl) phosphine hydrogen obtained in the step b) with 5, 5-bis (bromomethyl)-1, 5-dioxa-spiro [5, 5] undecane in a solvent under the action of alkali to obtain the polyketone ligand 3, 3-bis-[bis-(2-methoxyphenyl) phosphine methyl]-1, 5-dioxa-spiro [5, 5] undecane. Compared with the prior art, specific raw materials are selected to synthesize the polyketone ligand according to specific process steps, the reaction route is simple, needed equipment is simple, energy consumption is low, overall good interaction can be achieved, the product yield is high, quality is good, and the method is safe and easy to industrialize.
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- 9-BBN and chloride catalyzed reduction of chlorophosphines to phosphines and diphosphines
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The commercially available Lewis acid, 9-BBN and Lewis basic [Et4N]Cl are used as catalysts for the reduction of chlorophosphines R2PCl in the presence of phenylsilane. Aryl-chlorophosphines afford primarily diphosphines (P2R4) while secondary phosphines predominate for alkyl-substituted precursors. Use of the combined catalysts leads to reduced reaction time and temperature, providing a rapid, scalable, and facile protocol for the preparation of diphosphines or secondary phosphines.
- Andrews, Ryan J.,Elser, Iris,Stephan, Douglas W.
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supporting information
p. 1740 - 1743
(2022/02/17)
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- Hydrogen/Halogen Exchange of Phosphines for the Rapid Formation of Cyclopolyphosphines
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The hydrogen/halogen exchange of phosphines has been exploited to establish a truly useable substrate scope and straightforward methodology for the formation of cyclopolyphosphines. Starting from a single dichlorophosphine, a sacrificial proton "donor phosphine"makes the rapid, mild synthesis of cyclopolyphosphines possible: reactions are complete within 10 min at room temperature. Novel (aryl)cyclopentaphosphines (ArP)5 have been formed in good conversion, with the crystal structures presented. The use of catalytic quantities of iron(III) acetylacetonate provides significant improvements in conversion in the context of diphosphine (Ar2P)2 and alkyl-substituted cyclotetra- or cyclopentaphosphine ((AlkylP)n, where n = 4 or 5) formation. Both iron-free and iron-mediated reactions show high levels of selectivity for one specific ring size. Finally, investigations into the reactivity of Fe(acac)3 suggest that the iron species is acting as a sink for the hydrochloric acid byproduct of the reaction.
- Barrett, Adam N.,Woof, Callum R.,Goult, Christopher A.,Gasperini, Danila,Mahon, Mary F.,Webster, Ruth L.
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supporting information
p. 16826 - 16833
(2021/11/04)
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- Rapid Metal-Free Formation of Free Phosphines from Phosphine Oxides
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A rapid method for the reduction of secondary phosphine oxides under mild conditions has been developed, allowing simple isolation of the corresponding free phosphines. The methodology involves the use of pinacol borane (HBpin) to effect the reduction while circumventing the formation of a phosphine borane adduct, as is usually the case with various other commonly used borane reducing agents such as borane tetrahydrofuran complex (BH3?THF) and borane dimethyl sulfide complex (BH3?SMe2). In addition, this methodology requires only a small excess of reducing agent and therefore compares favourably not just with other borane reductants that do not require a metal co-catalyst, but also with silane and aluminium based reagents. (Figure presented.).
- Provis-Evans, Cei B.,Emanuelsson, Emma A. C.,Webster, Ruth L.
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supporting information
p. 3999 - 4004
(2018/09/21)
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- METHOD FOR PREPARING LIGAND FOR POLYKETONE POLYMERIZATION CATALYST
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The present disclosure provides a method for preparing ((2,2-dimethyl-1,3-dioxane-5,5-diyl)bis(methylene))bis(bis(2-methoxyphenyl)phosphine), a ligand for a polyketone polymerization catalyst, under mild conditions with high purity and high yield. Therefore, the preparation method of the present disclosure can be easily applied to mass production.
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Paragraph 44; 45; 46; 47
(2017/07/06)
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- POLYKETONE POLYMERIZATION CATALYST
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Provided are a novel polyketone polymerization catalyst and a method of preparing a ligand, which can reduce production costs and can enable commercial mass synthesis by using ((2,2-dimethyl-1,3-dioxane-5,5-diyl)bis(methylene))bis(bis(2-methoxyphenyl)phosphine) as a ligand constituting the polykeytone polymerization catalyst, the ligand having a simple structure and a small molecular weight while having high activity.
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Paragraph 0054
(2016/12/01)
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- Facile, Catalytic Dehydrocoupling of Phosphines Using β-Diketiminate Iron(II) Complexes
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Catalytic dehydrocoupling of primary and secondary phosphines has been achieved for the first time using an iron pre-catalyst. The reaction proceeds under mild reaction conditions and is successful with a range of diarylphosphines. A proton acceptor is not needed for the transformation to take place, but addition of 1-hexene does allow for turnover at 50°C. The catalytic system developed also facilitates the dehydrocoupling of phenylphosphane and dicyclohexylphosphane. A change in solvent switches off dehydrocoupling to allow hydrophosphination of alkenes.
- King, Andrew K.,Buchard, Antoine,Mahon, Mary F.,Webster, Ruth L.
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supporting information
p. 15960 - 15963
(2015/11/03)
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- Selective dehydrocoupling of phosphines by lithium chloride carbenoids
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The development of a simple, transition-metal-free approach for the formation of phosphorus-phosphorus bonds through dehydrocoupling of phosphines is presented. The reaction is mediated by electronically stabilized lithium chloride carbenoids and affords a variety of different diphosphines under mild reaction conditions. The developed protocol is simple and highly efficient and allows the isolation of novel functionalized diphosphines in high yields.
- Molitor, Sebastian,Becker, Julia,Gessner, Viktoria H.
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supporting information
p. 15517 - 15520
(2014/12/12)
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- NMR spectroscopy and structural characterization of dithiophosphinate ligands relevant to minor actinide extraction processes
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Synthetic routes to alkyl and aryl substituted dithiophosphinate salts that contain non-coordinating PPh4+ counter cations are reported. In general, these compounds can be prepared via a multi-step procedure that starts with reacting secondary phosphines, i.e. HPR2, with two equivalents of elemental S. The synthetic transformation proceeds by oxidation of the phosphine followed by insertion of S into the H-P bond. This approach was used to synthesize a series of dithiophosphinic acids that were fully characterized, namely HS2P(p-CF3C6H 4)2, HS2P(m-CF3C6H 4)2, HS2P(o-MeC6H4) 2 and HS2P(o-MeOC6H4)2. Although the insertion step was found to be much slower than the oxidation reaction, the formation of (NH4)S2PR2 from HPSR2 occurred rapidly upon addition of NH4OH. Subsequent cation exchange reactions proceeded readily with PPh4Cl in water, under air and at ambient conditions to provide analytically pure samples of [PPh4][S2PR2] (R = p-CF3C 6H4, m-CF3C6H4, o-CF 3C6H4, o-MeC6H4, o-MeOC6H4, Ph, and Me, 1b-7b, respectively), which were characterized by elemental analysis, multinuclear NMR, and IR spectroscopy. In addition, S2PPh2- and dithiophosphinates with ortho-substituted aryl groups (3b-6b) were characterized by X-ray crystallography. As opposed to the acids, which have short PS double bonds and long P-SH single bonds, the metric parameters for the S atoms in S 2PR2- are equivalent. In addition, the presence of large non-coordinating PPh4+ cations guard against intermolecular P-S...X interactions and ensure that the P-S bond is isolated. These S2PR2- anions, which can be prepared in large quantities and isolated in crystalline form, are attractive for spectroscopic and theoretical studies because the P-S interaction can be probed independently in the absence of intermolecular interactions.
- Daly, Scott R.,Klaehn, John R.,Boland, Kevin S.,Kozimor, Stosh A.,MacInnes, Molly M.,Peterman, Dean R.,Scott, Brian L.
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body text
p. 2163 - 2175
(2012/03/22)
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- Reduction of tertiary phosphine oxides with DIBAL-H
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(Chemical Equation Presented) The reduction of tertiary phosphine oxides (TPOs) and sulfides with diisobutylaluminum hydride (DIBAL-II) has been studied in detail. An extensive solvent screen has revealed that hindered aliphatic ethers, such as MTBE, are optimum for this reaction at ambient temperature. Many TPOs undergo considerable reduction at ambient temperature and then stall due to inhibition. 31P and 13C NMR studies using isotopically labeled substrates as well as competition studies have revealed that the source of this inhibition is tetraisobutyldialuminoxane (TIBAO), which builds up as the reaction proceeds. TIBAO selectively coordinates the TPO starting material, preventing further reduction. Several strategies have been found to circumvent this inhibition and obtain full conversion with this extremely inexpensive reducing agent for the first time. Practical reduction protocols for these critical targets have been developed.
- Busacca, Carl A.,Raju, Ravinder,Grinberg, Nelu,Haddad, Nizar,James-Jones, Paul,Lee, Heewon,Lorenz, Jon C.,Saha, Anjan,Senanayake, Chris H.
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p. 1524 - 1531
(2008/04/12)
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- A superior method for the reduction of secondary phosphine oxides
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(Chemical Equation Presented) Diisobutylaluminum hydride (DIBAL-H) and triisobutylaluminum have been found to be outstanding reductants for secondary phosphine oxides (SPOs). All classes of SPOs can be readily reduced, including diaryl, arylalkyl, and dialkyl members. Many SPOs can now be reduced at cryogenic temperatures, and conditions for preservation of reducible functional groups have been found. Even the most electron-rich and sterically hindered phosphine oxides can be reduced in a few hours at 50-70°C. This new reduction has distinct advantages over existing technologies.
- Busacca, Carl A.,Lorenz, Jon C.,Grinberg, Nelu,Haddad, Nizar,Hrapchak, Matt,Latli, Bachir,Lee, Heewon,Sabila, Paul,Saha, Anjan,Sarvestani, Max,Shen, Sherry,Varsolona, Richard,Wei, Xudong,Senanayake, Chris H.
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p. 4277 - 4280
(2007/10/03)
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- Synthesis, characterization, and reactivity of neutral and cationic Pd-C,N,N pincer complexes
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The ortho-palladation of the iminophosphane ligand 6-phenyl-2-[(2,6- diisopropylphenyl)imino]pyridine (HL) with Pd(OAc)2 and PdCl 2(PhCN)2 in benzene yields the neutral Pd-C,N,N pincer complexes Pd(OAc)(κ3-C,N,N
- Bianchini, Claudio,Lenoble, Geraldine,Oberhauser, Werner,Parisel, Sebastien,Zanobini, Fabrizio
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p. 4794 - 4800
(2007/10/03)
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- Reductive cleavage of the carbon-phosphorus bond with alkali metals. III Reactions of arylalkylphosphines
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The reductive cleavage of phenylalkylphosphines Ph2PR, PhPR2 (R = Bu, iPr) with Na/NH3 is unselective; both phenyl and alkyl groups can be cleavaged and Birch reduction may occur.Reaction of Ph2tBuP gives a high yield of diphenylphosphide.Polar groups (CO2Na, SO3Na) at the ω position of primary alkyl groups may lead to an increase in selectivity; Birch reduction is suppressed and a functionalised secondary phosphide is obtained.From diarylbenzyl- and diarylallylphosphines, the benzyl and allyl groups are selectively removed; Ar2PH and ArRPH are formed in high yield after hydrolytic work-up unless the aryl group bears F, CF3 or (CH3)2N substituents.From the reaction mixture of Ph2PCH2Ph we have isolated 1,2-diphenylethane. 2-Methoxyphenyl and 2,6-dimethoxyphenyl groups are selectively removed from Ar2BuP, ArPhBuP and Ar2P(CH2)3PAr2, forming ArBuPH, PhBuPH and ArP(H)(CH2)3(H)PAr, respectively.A double-cleavage reaction of Ar2RP may occur in low yield. 2,6-(dimethoxyphenyl-dibutylphosphine gives dibutylphosphine in moderate yield.When compounds with a 2,6-dimethoxyphenyl moiety are allowed to react with Li/THF, removal of a methyl group leads to novel phosphinophenols.It is concluded that cleavage of alkyl groups R selectively occurs when R radical is relatively stable (tBu, PhCH2> iPr > Bu).
- Doorn, Johannes A. van,Meijboom, Nico
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p. 170 - 177
(2007/10/02)
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- Reductive cleavage of the carbon-phosphorus bond with alkali metals. I. Cleavage of functionalised triphenylphosphines; formation of secondary and primary phosphines
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The reductive cleavage reaction of functionalised triphenylphosphines 1-34 with Na/NH3 and Li/THF depends strongly on the nature of the functionality and on the reducing agent. No reduction occurs with 11, 24, 30, 31 and 32 in Na/NH3.Compounds 3, 4, 5, 10, 12, 13, 15, 19, 23, 25, 26 and 27 cleave to give the secondary phosphide in high yield with Na/NH3, whereas 2, 7 and 9 give a high yield with Li/THF.Reduction occurs but cleavage is poor with 6, 7, 14, 29 and 34 and Na/NH3, or with 11 and Li/THF.Primary ortho-functionalised phenyl phosphines are obtained by a double cleavage reduction from 2, 5, 12, 25, 26 and 27 with Na/NH3.This unprecedented reaction proceeds via the secondary phosphine, which is formed by protonation of the corresponding phosphide with NH3.It occurs when the aryl group contains a strongly electron-donating substituent.Multiple cleavage of aryl groups with extended ? systems occurs with 7 and 34 when they are made to react with Li/THF.Halogens are cleaved from the phenyl group (16, 17, 18, 28 and 33, with Na/NH3), whereas SCH3 groups are converted to the corresponding mercapto group (20, 21 and 22).Birch reduction (2 and 10) can take place in NH3 but not in the aprotic solvent THF; it occurs only when other reactions are slow.Sodium amide is obtained via reaction of 8 in Na/NH3.Restricted Hartree-Fock calculations were carried out for a number of substituted phenylphosphines.From the correlation between the energies and coefficients of the LUMO (always an aryl ?* orbital) and the experimental cleavage data, it was concluded that there are three requirements for successful cleavage.The LUMO energy should be neither too high (no reduction) nor too low (radical anion too stable) and, further, the coefficient of the LUMO on the carbon attached to phosphorus must be large.
- Budzelaar, Peter H. M.,Doorn, Johannes A. van,Meijboom, Nico
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p. 420 - 432
(2007/10/02)
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- Bisphosphine production
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Bis[di(alkoxyphenyl)phosphino]alkanes are produced by reacting an alkoxyphenyl Grignard with phosphorus trichloride and converting the resulting di(alkoxyphenyl)phosphorus chloride to the corresponding phosphine. The di(alkoxyphenyl)phosphine is reacted w
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