- The Formation of P-C Bonds Utilizing Organozinc Reagents for the Synthesis of Aryl- A nd Heteroaryl-Dichlorophosphines
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Aryl- A nd heteroaryl-dichlorophosphines are mildly and selectively made in a one-pot synthesis in moderate to good yields starting from the respective aryl bromides or five-membered heterocycles, following lithiation with nBuLi, transmetalation with ZnCl
- Kirst, Christin,Tietze, Jonathan,Ebeling, Marian,Horndasch, Lukas,Karaghiosoff, Konstantin
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p. 17337 - 17343
(2021/11/18)
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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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- AlCl3-catalyzed C-H p hosphination of benzene: A mechanistic study
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The characteristics of the reaction for the preparation of dichlorophenylphosphine (DCPP) via benzene and PCl3 in the presence of AlCl3 were studied. Some unique characteristics were observed when a catalytic amount of AlCl3 was used. Namely, more than one mole of DCPP was obtained per mole AlCl3, the reaction solution was layered, and DCPP could be directly separated. Our mechanistic study showed that benzene reacted with PCl3 to form DCPP-AlCl3, and DCPP-AlCl3 dissociated into DCPP and AlCl3, continuing to catalyze this reaction. This resulted in the high catalytic efficiency of AlCl3. The layering of the reaction solution was caused by the immiscibility of DCPP-AlCl3 with the raw materials, greatly facilitating the dissociation process of DCPP-AlCl3. The formation of diphenylphosphorus chloride (DPC) was due to a continuous Friedel-Crafts reaction between DCPP and benzene. DPC cooperated with AlCl3 to form the stable coordination compound DPC-AlCl3 that did not dissociate and was responsible for the deactivation of AlCl3.
- Duan, Haodong,Gao, Jun,Guo, Ge,Han, Yuxi,Leng, Kangwei,Li, Xinjin,Wang, Zhongwei,Xu, Xiaolei,Yu, Qing
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- Base-induced 1,3-sigmatropic rearrangement of mesitylphosphonium salts
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Attempted synthesis of the ylide dianion [2,4,6-Me3C6H2P(CHR)3]2- (2,4,6-Me3C6H2 = mesityl, R = H or Me) by the reaction of mesitylphosphonium iodides [2,4,6-Me3C6H2PR3]+I- (R = Me, 1; R = Et, 2) with tBuLi at reflux does not result in the anticipated deprotonation of the phosphorus-bonded R groups. Instead, quantitative 1,3-sigmatropic rearrangement occurs to give new benzylic phosphonium salts [(3,5-Me2C6H3)CH2PR3]+I- (R = Me, 6; R = Et, 7), in which the phosphonium centre, the R3P group, is transferred to an ortho-CH3 group. In situ 31P NMR spectroscopic studies show that the reaction is base-activated and stoichiometric with respect to tBuLi. DFT calculations support the conclusion that the rearrangement is thermodynamically favourable in the gas phase and in THF and show that the rearrangement is enthalpically driven. Teaching an old dog new tricks: First synthesised in 1935, phosphonium salts [2,4,6-Me3C6H2PR3]+I- (2,4,6-Me3C6H2 = mesityl, R = Me or Et) exhibit an unexpected quantitative rearrangement in the presence of tBuLi, in which the phosphine group R3P is transferred to an ortho-CH3 position.
- Solomon, Sophia A.,Allen, Lucy K.,Dane, Sarah B. J.,Wright, Dominic S.
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supporting information
p. 1615 - 1619
(2015/04/27)
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- Base-Induced 1,3-Sigmatropic rearrangement of mesitylphosphonium salts
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Attempted synthesis of the ylide dianion [2,4,6-Me3C 6H2P(CHR)3]2- (2,4,6-Me 3C6H2 = mesityl, R = H or Me) by the reaction of mesitylphosphonium iodides [2,4,6-Me3C6H 2PR3]+I- (R = Me, 1; R = Et, 2) with tBuLi at reflux does not result in the anticipated deprotonation of the phosphorus-bonded R groups. Instead, quantitative 1,3-sigmatropic rearrangement occurs to give new benzylic phosphonium salts [(3,5-Me2C 6H3)CH2PR3]+I - (R = Me, 6; R = Et, 7), in which the phosphonium centre, the R 3P group, is transferred to an ortho-CH3 group. In situ 31P NMR spectroscopic studies show that the reaction is base-activated and stoichiometric with respect to tBuLi. DFT calculations support the conclusion that the rearrangement is thermodynamically favourable in the gas phase and in THF and show that the rearrangement is enthalpically driven. Copyright
- Solomon, Sophia A.,Allen, Lucy K.,Dane, Sarah B. J.,Wright, Dominic S.
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supporting information
p. 1615 - 1619
(2014/04/17)
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- Copolymerization of ethylene and methyl acrylate by cationic palladium catalysts that contain phosphine-diethyl phosphonate ancillary ligands
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A series of benzo-linked phosphine-diethyl phosphonate (P-PO) and phosphine-bis(diethyl phosphonate) (P-(PO)2) ligands and the corresponding (P-PO)PdMe(2,6-lutidine)+ and (P-(PO) 2)PdMe(2,6-lutidine)+ complexes were synthesized. Cationic (P-PO)PdMe(2,6-lutidine)+ complexes are active for ethylene oligomerization/polymerization, with activities of 2 kg mol-1 h -1 for {κ2-1-PiPr2-2-P(O)(OEt) 2-5-Me-Ph}PdMe(2,6-lutidine)+ (3c), 125 kg mol -1 h-1 for {κ2-1-PPh2-2-P(O) (OEt)2-5-Me-Ph}PdMe(2,6-lutidine)+ (3a), and 1470 kg mol-1 h-1 for {κ2-1-P(2-OMe-Ph) 2-2-P(O)(OEt)2-Ph}PdMe(2,6-lutidine)+ (3b). The polyethylene is highly linear, with over 80% terminal unsaturation and low (230-1890 Da) molecular weight in all cases. 3b copolymerizes ethylene with methyl acrylate, exhibiting highly selective (95%) in-chain (rather than chain-end) acrylate incorporation. The P-(PO)2 catalyst {κ2-1-P(4-tBu-Ph)(2-P(O)(OEt)2-5-Me-Ph)- 2-P(O)(OEt)2-5-Me-Ph}PdMe(2,6-lutidine)+ (3d) is more active for ethylene homopolymerization (2640 kg mol-1 h -1), yielding linear, low-molecular-weight polymer (1280-1430 Da) with predominantly internal olefin placement. In ethylene/methyl acrylate copolymerization, 3d incorporates 2.6 mol % methyl acrylate, 60% of which is in-chain. Both 3b and 3d catalyze ethylene/acrylic acid copolymerization, albeit with low (-1 h-1) activities and acrylic acid incorporation up to 1.1 mol %.
- Contrella, Nathan D.,Sampson, Jessica R.,Jordan, Richard F.
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p. 3546 - 3555
(2014/08/05)
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- (p-tolyl)dichlorophosphine and di(p-tolyl)chlorophosphine sources of new organophosphorus(III) and (V) compounds
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The purpose of our present work was to study some chemical properties of p-tolyldichlorophosphine and di(p-tolyl)chlorophosphine involved in reactions with organo-lithium compounds, with 1,2-diols and also when are reactants in variants of Reformatsky and Mannich reactions, in order to obtain some new substances of trivalent and pentavalent phosphorus useful for our further investigations. All the new phosphorus(III) and (V) compounds were obtained in fair yields, and were characterized by elemental analysis, IR, and NMR spectroscopy. They will find potential synthetic utility as convenient ligands for transition metals and reagents for the preparation of phosphonium salts, for obtaining chiral substances and as biologically active ring substances.
- Fǎgǎdar-Cosma, Eugenia,Fǎgǎdar-Cosma, Gheorghe
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p. 211 - 217
(2007/10/03)
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- A direct and new convenient oxidation: Synthesis of substituted arylphosphonates from aromatics
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An easy synthesis of aryl phosphonates by oxidation from aryldichlorophosphines with iodine in good yields is described. Aryldichlorophosphines are obtained by reaction of phosphorous trichloride with some aromatics in presence of various Lewis acids. BiCl3 and Bi(OTf)3 are used for the first time and bismuth trichloride is, for the first time in the case of anisole or thioanisole phosphonylation, used as a true regenerable Lewis acid catalyst in a reaction of direct phosphonylation of aromatics.
- Simeon, Fabrice,Jaffres, Paul-Alain,Villemin, Didier
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p. 10111 - 10118
(2007/10/03)
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- Catalytic Enantioselective Hydrosilylation of Aromatic Ketones Using Rhodium Complexes of TADDOL-Derived Cyclic Phosphonites and Phosphites
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Cyclic phosphonites and phosphites 2-4 are readily available from Cl2PR and (R,R)- or (S,S)-α,α,α',α'-tetraaryl-1,3-dioxolane-4,5-dimethanols (=TADDOLs 1, which, in turn, are only two steps away from tartrate); the X-ray crystal structure of one representative, the phenyl phosphonite 2b, was determined.Five previously described and six new ones of the chiral P derivatives were tested as ligands for Rh1- and Pd0-catalyzed reactions such as hydrocarbonylations, hydroborations, and hydrosilylations of C=C bonds; while the resulting catalysts were highly active and regioselective, they did not lead to useful enantiomer enrichment in the products (Scheme 1).In contrast, hydrosilylation of phenyl and 2-naphthyl methyl or ethyl ketone by Ph2SiH2 (1.2 equiv.) gave, after desilylation, the corresponding secondary alcohols of (R)-configuration with up to 87percent ee in the presence of 0.1 equiv. of the penta(2-naphthyl)-substituted phosphonite 3d and 0.02 mol-equiv. of Rh (Table 1 ).
- Sakaki, Jun-ichi,Schweizer, W. Bernd,Seebach, Dieter
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p. 2654 - 2665
(2007/10/02)
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- Process for the preparation of phenyl- and thienyl-chlorophosphane derivatives
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Organic chlorophosphanes of the formula II STR1 in which R1 =an aromatic or heterocyclic radical and R2 =an aliphatic radical or Cl are prepared by reacting organic phosphorus oxychlorides of the formula I STR2 in which R1 and R2 have the meaning mentioned above with triphenylphosphane (C6 H5)3 P at an elevated temperature. The organic chlorophosphanes II are, in the main, intermediates in various specialized fields, such as the pharmaceuticals, plant protection, dyestuffs and polymers sectors.
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