- Intracellular disulfide reduction by phosphine-borane complexes: Mechanism of action for neuroprotection
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Phosphine-borane complexes are novel cell-permeable drugs that protect neurons from axonal injury in vitro and in vivo. These drugs activate the extracellular signal-regulated kinases 1/2 (ERK1/2) cell survival pathway and are therefore neuroprotective, b
- Niemuth, Nicholas J.,Thompson, Alex F.,Crowe, Megan E.,Lieven, Christopher J.,Levin, Leonard A.
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- Rhodium Complexes in P-C Bond Formation: Key Role of a Hydrido Ligand
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Olefin hydrophosphanation is an attractive route for the atom-economical synthesis of functionalized phosphanes. This reaction involves the formation of P-C and H-C bonds. Thus, complexes that contain both hydrido and phosphanido functionalities are of gr
- Varela-Izquierdo, Víctor,Geer, Ana M.,Navarro, Janeth,López, José A.,Ciriano, Miguel A.,Tejel, Cristina
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supporting information
p. 349 - 358
(2021/01/13)
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- Hydrophosphination of Activated Alkenes by a Cobalt(I) Pincer Complex
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Herein we report the synthesis of three heteroleptic first-row transition metal(II) complexes containing carbazolido NNN pincer ligands and conversion to the corresponding metal(I)-carbonyl complexes via a reductive carbonylation route. These complexes are precatalysts for the hydrophosphination of activated alkenes, affording a cobalt-catalysed hydrophosphination process that solely and selectively yields the β addition (anti-Markovnikov) product. The scope of this transformation has been investigated using a variety of activated alkenes. Isolation and characterisation of substrate-coordinated intermediates reveal available coordination sites, which provide insight into the proposed catalytic cycle. (Figure presented.).
- Nolla-Saltiel, Roberto,Geer, Ana M.,Taylor, Laurence J.,Churchill, Olivia,Davies, E. Stephen,Lewis, William,Blake, Alexander J.,Kays, Deborah L.
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supporting information
p. 3148 - 3157
(2020/06/08)
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- A bench-stable copper photocatalyst for the rapid hydrophosphination of activated and unactivated alkenes
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Cu(acac)2 (1) is a highly active catalyst for the hydrophosphination of alkenes. Photocatalytic conditions are critical, and provide high conversions with unactivated substrates that have never before been reported with an air-stable catalyst or at ambient temperature. The commercial availability, ease of use, and broad substrate scope of compound 1 make hydrophosphination more available to synthetic chemists.
- Dannenberg, Steven G.,Waterman, Rory
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supporting information
p. 14219 - 14222
(2020/11/24)
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- Catalyst-free hydrophosphination of alkenes in presence of 2-methyltetrahydrofuran: A green and easy access to a wide range of tertiary phosphines
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A hydrophosphination reaction that is free of base, acid and catalyst, using only 2-methyltetrahydrofuran as additive has been performed. A new family of mono-, di-, tri- and tetra-phosphines compounds are obtained in good to excellent yields by adding di
- Bissessar, Damien,Egly, Julien,Achard, Thierry,Steffanut, Pascal,Bellemin-Laponnaz, Stéphane
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p. 27250 - 27256
(2019/09/12)
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- Photocatalytic Hydrophosphination of Alkenes and Alkynes Using Diphenylphosphine and Triamidoamine-Supported Zirconium
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Reactions of alkene or alkyne with diphenylphosphine and catalytic [κ5-N,N,N,N,C-(Me3SiNCH2CH2)2NCH2CH2NSiMe2CH2]Zr (1) are greatly enhanced under photolysis, providing viable catalytic hydrophosphination with a broad substrate scope. Whereas diphenylphosphine had been an inaccessible substrate under thermal conditions, complete conversion of alkene substrates to tertiary phosphine is achieved in as little as four hours at ambient temperature with 1 under ultraviolet irradiation. Previously inactive alkenes are now hydrophosphination substrates with diphenylphosphine to produce tertiary phosphine ligands possessing tunable steric and electronic properties.
- Novas, Bryan T.,Bange, Christine A.,Waterman, Rory
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supporting information
p. 1640 - 1643
(2019/01/04)
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- Neutral and Cationic Zirconium Complexes Bearing Multidentate Aminophenolato Ligands for Hydrophosphination Reactions of Alkenes and Heterocumulenes
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Zirconium complexes supported by multidentate aminophenolato ligands were synthesized and characterized. The catalytic activities of neutral zirconium complexes and their cationic derivatives in the hydrophosphination of alkenes as well as heterocumulenes have been investigated and compared. Neutral complex 1 bearing a multidentate amino mono(phenolato) ligand exhibited high activity in hydrophosphination of simple alkenes, and anti-Markovnikov products were obtained in 37-94% yields at room temperature. Cationic species generated in situ from complex 3 stabilized by a bis(phenolato) ligand were found to be more active for hydrophosphination of heterocumulenes, i.e., carbodiimides and isocyanates, and gave phosphaguanidines and phosphaureas in 67-93% yields. The Lewis acidity and coordination space of metal centers are modified through changes in the ligand structure, which is found to significantly influence catalytic activity. These complexes are among the most active group 4 metal-based catalysts for hydrophosphination reactions.
- Zhang, Yu,Qu, Liye,Wang, Yaorong,Yuan, Dan,Yao, Yingming,Shen, Qi
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p. 139 - 149
(2018/01/11)
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- Rosuvastatin intermediate compound and preparation method and application thereof
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The invention relates to an intermediate compound for preparation of rosuvastatin calcium. A structure of the intermediate compound is shown as a formula (I), and the intermediate compound is stable and high in nucleophilicity and reaction activity. In addition, the invention further relates to a preparation process suitable for industrial production of rosuvastatin calcium. Due to adoption of the intermediate compound, a rosuvastatin calcium preparation method is mild in reaction condition, free of ultralow-temperature equipment, simple in aftertreatment and easy in operation, and intermediate product olefin which is an intermediate compound shown as a formula (III) is high in stereoselectivity and yield, high in product quality and high in economic benefit.
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Paragraph 0027
(2017/08/29)
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- Iron catalysis for the synthesis of ligands: Exploring the products of hydrophosphination as ligands in cross-coupling
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Catalytic hydrophosphination is a useful technique for the synthesis of phosphines, however, the phosphine products have been little exploited as ligands in catalysis. We have selected three phosphines prepared by iron catalyzed hydrophosphination and used them as ligands in a series of cross-coupling reactions: Heck, Suzuki-Miyaura and Buchwald-Hartwig. Rather than limit the chemistry to simple cross-coupling partners which are almost guaranteed to perform well in these transformations, industrially relevant substrates which are challenging from and electronic and/or steric perspective, along with substrates which contain several heteroatoms, were explored in order to gauge the true potential of these phosphine ligands.
- Espinal-Viguri, Maialen,Mahon, Mary F.,Tyler, Simon N.G.,Webster, Ruth L.
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- Visible Light Photocatalysis Using a Commercially Available Iron Compound
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[CpFe(CO)2]2 (1) (Cp = η5-C5H5) is an effective precatalyst for the hydrophosphination of alkenes with Ph2PH under visible light irradiation, which appears to be a unique way to promote metal-catalyzed hydrophosphination. Additionally, 1 is a photocatalyst for the dehydrogenation of amine boranes and formation of siloxanes from tertiary silanes. These reactions have similar, if not improved, reactivity over the same transformations using 1 or related CpFeMe(CO)2 under UV irradiation, consistent with the notion that hydrophosphination with 1 proceeds via formation of CpFe(CO)2?. These results demonstrate that catalyst selection can avail the use of commercially available LED bulbs as photon sources, potentially replacing mercury arc lamps or other energy intensive processes in known or new catalytic reactions.
- Pagano, Justin K.,Bange, Christine A.,Farmiloe, Sarah E.,Waterman, Rory
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supporting information
p. 3891 - 3895
(2017/10/30)
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- A Study of Two Highly Active, Air-Stable Iron(III)-μ-Oxo Precatalysts: Synthetic Scope of Hydrophosphination using Phenyl- and Diphenylphosphine
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The importance of phosphines in synthetic chemistry cannot be underestimated. Catalytic hydrophosphination offers an ideal method to prepare P?C bonds without the need for harsh reaction conditions or stoichiometric amounts of waste by-product. We herein report our studies into two biocompatible iron(III) complexes in hydrophosphination chemistry using diphenylphosphine under mild and benign reaction conditions (room temperature, solvent-free) and our extended exploration of hydrophosphination with phenylphosphine, which can be tuned to operate in the absence of catalyst under thermal conditions for single hydrophosphination or solvent-free with an iron(III) precatalyst to generate the products of double hydrophosphination. (Figure presented.).
- Gallagher, Kimberley J.,Espinal-Viguri, Maialen,Mahon, Mary F.,Webster, Ruth L.
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p. 2460 - 2468
(2016/08/16)
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- Synthesis and molecular structures of divalent bridged bis(guanidinate) europium complexes and their application in intermolecular hydrophosphination of alkenes and alkynes
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The reaction of anhydrous EuCl3 with one equiv. of lithium salt of a three-carbon bridged bis(guanidinate) Li2L1 (L1 = [iPr(Me3Si)NC(NiPr)N(CH2)3NC(NiPr)N(SiMe3)iPr]) in THF afforded chloride EuIIIL1Cl(THF)2 (1). The reduction reaction of complex 1 with Na/K alloy in a molar ratio of 1?:?1.2 in THF gave a novel EuII complex supported by an unexpected new bridged bis(guanidinate) ligand L3, [EuIIL3]2 (L3 = [iPr(Me3Si)NC(NiPr)N(CH2)3N(SiMe3)C(NiPr)2]) (2), through the redistribution of one guanidinate in L1 during the reduction. Complex 2 was structurally characterized to be a binuclear complex in which two Eu metals are connected together by two L3 ligands that adopted a μ-η1:η2:η2 coordination mode for one L3 ligand and a μ-η2:η2:η2 mode for the other. Treatment of the in situ formed EuIIIL2Cl(THF)2 (L2 = 1,8-C10H6{NC(NiPr)(NHiPr)}2) by the reaction of EuCl3 with 0.5 equiv. of [Li2L22Li2] in THF with Na/K alloy yielded a novel EuII complex [EuIIL2(THF)]2 (3) in good yield. Complex 3 was characterized by an X-ray crystal structure analysis. Complex 3 features an unusual μ-η1:η2:η2 coordination mode of the bridged bis(guanidinate) ligand onto EuII. Complexes 2 and 3 are efficient pre-catalysts for the intermolecular hydrophosphination of alkenes and alkynes to give exclusively anti-Markovnikov products and mainly anti-addition products for the alkyne reactions. For these transformations, the best performances were observed with complex 2.
- Liu, Qianqian,Wang, Chuanyong,Zhang, Xingmin,Xue, Mingqiang,Yao, Yingming,Zhang, Yong,Shen, Qi
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supporting information
p. 10447 - 10454
(2016/12/06)
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- Room temperature hydrophosphination using a simple iron salen pre-catalyst
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Phosphines are fundamentally important to the fine chemicals, pharmaceutical and agrochemical industries. Reported is the first example of alkene hydrophosphination using a designed iron pre-catalyst which yields the anti-Markovnikov products in high yield at room temperature. The phosphine products are excellent pro-ligands for Fe-catalyzed Negishi cross-coupling. This journal is
- Gallagher,Webster
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supporting information
p. 12109 - 12111
(2015/01/08)
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- Conversion of azides into diazo compounds in water
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Diazo compounds are in widespread use in synthetic organic chemistry but have untapped potential in chemical biology. We report on the design and optimization of a phosphinoester that mediates the efficient conversion of azides into diazo compounds in phosphate buffer at neutral pH and room temperature. High yields are maintained in the presence of common nucleophilic or electrophilic functional groups, and reaction progress can be monitored by colorimetry. As azido groups are easy to install and maintain in biopolymers or their ligands, this new mode of azide reactivity could have substantial utility in chemical biology.
- Chou, Ho-Hsuan,Raines, Ronald T.
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supporting information
p. 14936 - 14939
(2013/11/06)
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- A green procedure for the regio- and chemoselective hydrophosphonylation of unsaturated systems using CaO under solventless conditions
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Diethyl phosphite and diphenylphosphine add to a series of unsaturated derivatives using environmentally-friendly calcium oxide as a basic promoter under solventless conditions at room temperature. The corresponding adducts are obtained in a totally regio
- Martinez-Castro, Elisa,Lopez, Oscar,Maya, Ines,Fernandez-Bolanos, Jose G.,Petrini, Marino
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supporting information; experimental part
p. 1171 - 1174
(2010/10/18)
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- Synthesis and characterisation of [Re(CO)3(SS)(P)] complexes: A [2+1] concept for 99mTc- and 188Re-radiopharmaceutical applications
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A new (SS)(P) coordination set based on the concurrent use of a dithiocarbamate and a functionalised phosphane is reported. The (SS)(P) fashion is achieved by applying the [2+1] mixed-ligand concept and makes it possible to obtain stable rhenium tricarbonyl complexes without employing tripodal bifunctional chelating agents (BFCAs). The coordination chemistry of the simple sodium N,N-dimethyldithiocarbamate and new functionalised phosphanes L1-L3 [L1 = Ph2PCH2CH2C(O)OCH3, L2 = Ph 2PCH2CH2C(O)NHCH2C(O)OCH 3, L3 = Ph2PCH2CH2C(O)NHCH 2CH2C(O)OCH3] was studied by reaction with the rhenium complex [NEt4]2-[fac-Re(CO3)Br 3]. The rhenium tricarbonyl core was found to be stabilised by the SS chelation of dithiocarbamate and by the P coordination of the phosphane. Two synthetic pathways leading to the complexes [fac-Re(CO)3(L)(MDTC)] (L = L1, L2, L3; MDTC = N,N-dimethyldithiocarbamate) are described. The structural characterisation of the isolated complexes by spectroscopic methods is reported, including X-ray crystallographic analysis for rhenium complexes with ligands L1 and L3. The homologous Tc-99m compounds with the same (SS)(P) coordination set were prepared at tracer level with the L2 and L3 ligands, and characterised by HPLC methods. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Riondato, Mattia,Camporese, Davide,Martin, David,Suades, Joan,Alvarez-Larena, Angel,Mazzi, Ulderico
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p. 4048 - 4055
(2007/10/03)
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- Approaches to water-soluble phosphines. II. Free radical addition reactions of phenylphosphines
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Free radical additions of diphenylphosphine, phenylphosphine and ethylenebis(phenylphosphine) to the following species are described: alkynols, alkyne ethers, unsaturated carboxylic acids and esters and β-lactones.In a number of cases, these lead to water-soluble phosphines.NMR spectroscopic characterization of all new products has been carried out.Key words: Phosphine; Water soluble phosphines; Radical addition; Chirality
- Heesche-Wagner, Kerstin,Mitchell, Terence N.
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- Addition of diphenylphosphine to Michael-type olefins: the preparation of phosphine-nitrile and phosphine-ester ligands
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The reactions of five Michael-type olefins with diphenylphosphine have been carried out. 1-Cyanocyclopentene, 1-cyanocyclohexene, and 4-t-butyl-1-cyanocyclohexene all provide the corresponding 2-diphenylphosphino-1-cyanocycloalkanes, and both methyl acrylate and ethyl methacrylate yield to corresponding 2-diphenylphosphinopropionates.For the products from 1-cyanocyclopentene and 1-cyanocyclohexene, 13C and 31P NMR data are consistent with the formation of both trans (Ph2P equatorial and CN axial) and cis (both Ph2P and CN equatorial) isomers.The morpholine amide of 3-diphenylphosphinopropionic acid has been obtained by treatment of methyl-3-diphenylphosphinopropionate with the dimethylaluminum adduct of morpholine.This phosphine, Ph2Pmorph, has been isolated as its palladium(II) complex, (Ph2Pmorph)2PdCl2.A phosphine-benzaldimine, Ph2P(CH2)3NC(H)C6H5, has been obtained by reacting Ph2P(CH2)3NH2, from the reduction of PhP(CH2)2CN, with benzaldehyde in the presence of molecular sieves.
- Blinn, D.A.,Button, R.S.,Farazi, V.,Neeb, M.K.,Tapley, C.L.,et al.
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p. 143 - 152
(2007/10/02)
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