- 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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- 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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- Palladium nanocatalysts in glycerol: Tuning the reactivity by effect of the stabilizer
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Palladium nanoparticles (PdNPs) prepared in neat glycerol containing TPPTS (tris(3-sulfophenyl)phosphine trisodium salt) or cinchona-based alkaloids (cinchonidine, quinidine) as capping agents, were applied as catalysts in fluoride-free Hiyama couplings and conjugate additions with the aim of evaluating the influence of the stabilizer in the catalytic reactivity. Therefore, PdNPs stabilized by phosphine favored C–C cross-couplings, whereas those containing alkaloids showed enhanced suitability for C–C homo-couplings and conjugate additions. The metal/stabilizer coordination mode, i.e. Pd–P dative bond and π-π interaction between quinoline moiety and palladium surface, is certainly key for the stabilization of different active metallic species and then promoting distinctive catalytic pathways.
- Reina, Antonio,Serrano-Maldonado, Alejandro,Teuma, Emmanuelle,Martin, Erika,Gómez, Montserrat
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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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- Tin-catalyzed hydrophosphination of alkenes
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Simple tin derivatives, Cp?2SnCl2 (1) and Ph2SnCl2 (2), catalyze the hydrophosphination of alkene substrates with diphenylphosphine. Competitive dehydrocoupling to give Ph4P2 was observed, but this side reaction can be mitigated when the catalysis is conducted under an H2 atmosphere. Efforts to prepare stable tin bis(phosphido) compounds commonly resulted in decomposition to Ph4P2. Lewis acidic inorganic tin compounds do not show dehydrocoupling reactivity. It was found that the Lewis acid, B(C6F5)3, is able to engage in the hydrophosphination of alkenes, but it is poorly effective under the conditions tested.
- Stelmach, John P. W.,Bange, Christine A.,Waterman, Rory
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p. 6204 - 6209
(2016/04/26)
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- Catalyst- and solvent-free hydrophosphination and multicomponent hydrothiophosphination of alkenes and alkynes
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The hydrophosphination of carbon-carbon multiple bonds has been generally performed under acid, base or metal catalysis in different solvents. Herein, alkyl and alkenyl tertiary phosphines are obtained by the addition of diphenylphosphine to alkenes and alkynes, respectively, in the absence of a solvent and a catalyst. In the presence of elemental sulfur, the corresponding alkyl and alkenyl tertiary phosphine sulfides are synthesized in a three-component process. These simple methods, which meet most of the principles of Green Chemistry, are highly regioselective towards the anti-Markovnikov products and diastereoselective towards the Z alkenyl phosphines. The mechanistic aspects of the reactions are also tackled and the efficiency of the latter is compared with that of the catalytic methods.
- Moglie, Yanina,González-Soria, María José,Martín-García, Iris,Radivoy, Gabriel,Alonso, Francisco
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supporting information
p. 4896 - 4907
(2016/10/06)
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- Cobalt Phosphino-α-Iminopyridine-Catalyzed Hydrofunctionalization of Alkenes: Catalyst Development and Mechanistic Analysis
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A family of CoCl2(PNpy) complexes were prepared, where PNpy = 2-iminopyridyl-phosphine ligands derived from aminoalkyl and aminoaryl phosphines and 2-keto- and 2-formylpyridines. Reduction of CoCl2(PNpy) complexes in the presence of
- Chu, Wan-Yi,Gilbert-Wilson, Ryan,Rauchfuss, Thomas B.,Van Gastel, Maurice,Neese, Frank
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supporting information
p. 2900 - 2914
(2016/11/02)
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- Inner- and Outer-Sphere Roles of Ruthenium Phosphido Complexes in the Hydrophosphination of Alkenes
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An inner-sphere synthetic cycle for the hydrophosphination of alkenes is proposed, based on observed [2 + 2] cycloaddition of a wide range of alkenes at a coordinatively unsaturated Ru=PR2 complex. Key intermediates in the cycle were prepared, and their reactions with various organic acid/base pairs were examined to identify both new ruthenium precursors and base cocatalysts that allow turnover of the proposed cycle. Two new cationic ruthenium indenyl phosphine complexes were isolated and structurally characterized. Although preliminary screening studies show the moderate activity of these and related neutral phosphido complexes for catalytic hydrophosphination of acrylonitrile by both HPPh2 and HPCy2, and comparable activity for the hydrophosphination of tert-butyl acrylate by HPPh2, no activity was observed for the analogous hydrophosphination of 1-hexene. This is attributed to strong binding of the substrate phosphine to the unsaturated, planar Ru - PR2 fragment generated in situ, which inhibits the inner-sphere, alkene cycloaddition mechanism. An alternative, outer-sphere Michael addition process, involving a saturated complex with a strongly nucleophilic pyramidal Ru-PR2 ligand, is proposed to rationalize the observed selectivity for catalytic hydrophosphination of activated, but not simple, alkenes. Implications for further catalyst development are discussed.
- Belli, Roman G.,Burton, Krista M. E.,Rufh, Stephanie A.,McDonald, Robert,Rosenberg, Lisa
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p. 5637 - 5646
(2015/12/23)
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- Reactivity of ruthenium phosphido species generated through the deprotonation of a tripodal phosphine ligand and implications for hydrophosphination
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The fragmentation of the 1,1,2-tris(diphenylphosphino)ethane ligand in [RuCp((Ph2P)2CHCH2PPh2)][PF 6] (1) was explored through treatment with base under aprotic conditions. The neutral phosphido complex RuCp(PPh2CH - CHPPh 2)(PPh2) (2) with a (Z)-1,2-bis(diphenylphosphino)ethene (dppen) ligand was generated through a base-facilitated dehydrophosphination reaction. Installation of a bis(p-tolyl)phosphido ligand was attempted by combining bis(p-tolyl)phosphine with RuCp(dppen)Cl in the presence of KOtBu, but surprisingly, the unsymmetrical diphenylphosphido compound RuCp(Ph 2PCHCHP(p-tol)2)(PPh2) (5) was generated instead. The ligand rearrangement reaction was driven by the greater electron density on the bis(p-tolyl)phosphido moiety. Density functional theory calculations showed that fragmentation to the 1,2-disubstituted ligand was thermodynamically favored over the 1,1-disubstituted ligand and that intramolecular phosphido exchange was kinetically accessible at room temperature. The greater basicity of the bis(p-tolyl)phosphido ligand was experimentally verified by the measured pKaTHF of 28 for the acid/base pair [RuCp(Ph2P(o-C6H4)PPh2)(P(p-tolyl) 2H)]+/RuCp(Ph2P(o-C6H 4)PPh2)(P(p-tolyl)2) versus 25 for the acid/base pair [RuCp(Ph2P(o-C6H4)PPh 2)(PPh2H)]+/RuCp(Ph2P(o-C 6H4)PPh2)(PPh2) (7). For comparison, the approximate pKa THF values for free P(p-tolyl)2H/[K(crypt)]P(p- tolyl)2 and free PPh2H/[K(crypt)]PPh2 are 43 and 38, respectively. This is the first quantitative measurement of the large effect that coordination to a metal center, in this case ruthenium(II), has on the acidity of secondary phosphines. This is useful information for designing and understanding hydrophosphination catalysts. Complexes 2 and 7 are catalysts for the addition of PPh2H to acrylonitrile, but they deactivate fairly rapidly. The pKa THF measurements are consistent with a catalytic cycle involving a Michael addition step. Complex 2 in solution underwent a slow, unprecedented rearrangement of P-C, C-C, and C-H bonds to give crystalline Ru(C5(CH3)4(CH2C6H 5))(Ph2PCH2CH2PPh(o-C 6H4)PPh) (9) in high yields, demonstrating the unpredictable reactivity of phosphido ligands.
- Sues, Peter E.,Lough, Alan J.,Morris, Robert H.
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p. 4746 - 4760
(2014/04/17)
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- Palladium nanoparticles in glycerol: A versatile catalytic system for C-X bond formation and hydrogenation processes
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Palladium nanoparticles stabilised by tris(3-sulfophenyl)phosphine trisodium salt in neat glycerol have been synthesised and fully characterised, starting from both Pd(II) and Pd(0) species. The versatility of this innovative catalytic colloidal solution has been proved by its efficient application in C-X bond formation processes (X=C, N, P, S) and C-C multiple bond hydrogenation reactions. The catalytic glycerol phase could be recycled more than ten times, preserving its activity and selectivity. The scope of each of these processes has demonstrated the power of the as-prepared catalyst, isolating the corresponding expected products in yields higher than 90%. The dual catalytic behaviour of this glycerol phase, associated to the metallic nanocatalysts used in wet medium (molecular- and surface-like behaviour), has allowed attractive applications in one-pot multi-step transformations catalysed by palladium, such as C-C coupling followed by hydrogenation, without isolation of intermediates using only one catalytic precursor. Copyright
- Chahdoura, Faouzi,Pradel, Christian,Gomez, Montserrat
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supporting information
p. 3648 - 3660
(2014/01/06)
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- Solvent- and catalyst-free regioselective hydrophosphanation of alkenes
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The hydrophosphanation of alkenes, an atom-economy process typically promoted by radicals or metal species, has been shown to take place in the absence of a catalyst, under solvent-free conditions and in a regioselective manner.
- Alonso, Francisco,Moglie, Yanina,Radivoy, Gabriel,Yus, Miguel
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supporting information
p. 2699 - 2702
(2012/11/07)
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- Catalytic conjugate additions of nitrogen-, phosphorus-, and carbon-containing nucleophiles by amphoteric vanadyl triflate
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(Chemical Equation Presented) A series of carbamates, amides, N-tosyl amides, (hetero)arenes, and hydrogen phosphines/phosphites has been examined as nucleophiles for (hetero)Michael-type additions to enones and enamides catalyzed by amphoteric vanadyl triflate under mild and neutral conditions. The newly developed C-N, C-P, and C-C bond-formation protocols were carried out smoothly in good to high yields without intervention of any 1,2-additions.
- Lin, Yow-Dzer,Kao, Jun-Qi,Chen, Chien-Tien
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p. 5195 - 5198
(2008/09/17)
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- Regio- and stereoselective synthesis of alkenylphosphines: A rhodium-catalyzed hydrophosphination of alkynes using a silylphosphine
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(Chemical Equation Presented) A novel rhodium-catalyzed hydrophosphination of alkynes using a silylphosphine as a phosphino group source is described. A variety of alkynes, both terminal and internal ones with aryl, alkyl, and carboxyl groups, gave the co
- Hayashi, Minoru,Matsuura, Yutaka,Watanabe, Yutaka
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p. 9248 - 9251
(2007/10/03)
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- Preparation of a Nafion-Teflon bimembrane-supported palladium catalyst and its use in the Heck reaction
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A novel palladium catalyst supported on the Nafion membrane, reinforced with poly(tetrafluoroethylene) fiber, has been prepared. The catalyst exhibits high activity and stability in the Heck arylation reactions of aryl iodides with olefins and Sonogashira couplings with phenylacetylene, and can be readily recovered and reused twenty times without significant loss of activity.
- Li, Yangzhou,Li, Zhiming,Li, Feng,Wang, Quanrui,Tao, Fenggang
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p. 6159 - 6162
(2007/10/03)
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- Fluoride-mediated phosphination of alkenes and alkynes by silylphosphines
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Regioselective phosphination of carbon-carbon unsaturated bonds by a fluoride-mediated reaction of silylphosphines is described. Alkenes and alkynes having a directing group, such as an aromatic or a carbonyl group, reacted to form a carbon-phosphorus bon
- Hayashi, Minoru,Matsuura, Yutaka,Watanabe, Yutaka
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p. 9167 - 9169
(2007/10/03)
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- The kinetics and mechanism of the phosphorus-catalysed dimerisation of acrylonitrile
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Isopropyl diarylphosphinites (Ar2POPri) catalyse the dimerisation of acrylonitrile (AN) to a mixture of cis- and trans-1,4-dicyanobut-1-ene (cis,trans-DCB-1), trans-1,4-dicyanobut-2-ene (DCB-2) and 2,4-dicyanobut-1-ene (MGN). The kinetics and mechanism of the reaction, which is a potential source of hexamethylenediamine, are reported in detail and the factors which govern rate and selectivity to DCB-1 and DCB-2 rather than MGN are elaborated.
- Hall, C. Dennis,Lowther, Nicholas,Tweedy, Bruce R.,Hall, Adam C.,Shaw, Gordon
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p. 2047 - 2054
(2007/10/03)
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- Dual Radical/Polar Pudovik Reaction: Application Field of New Activation Methods
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The Pudovik reaction (addition of organophosphorus compounds containing a labile P-H bond with alkenes and alkynes) can progess via a radical or (and) ionic mechanism. A comparative and systematic study including various reagents and different activation methods (heating, photochemical or ultrasonic irradiation, and dry medium supported reactions) is presented. Photolysis is the most efficient method for the radical processes, but in a few examples, ultrasonic irradiation can be more appropriate since the reaction time is shorter and ultrasound did not induce side-reactions (in particular Z/E isomerization). Dry medium process on basic solid support is the best anionic activation (yield, time, selectivity, purification facilities). Ultrasound, by its mechanical effects, can contribute to increase yield compared to the classical thermal method under these basic conditions. All the activation methods are efficient whatever the unsaturated substrates for the phosphine reactivity, whereas the appropriate activation method is exclusively determined by the nature of the unsaturated system for the thiophosphine (or phosphine oxide) reactivity.
- Semenzin, Delphine,Etemad-Moghadam, Guita,Albouy, Dominique,Diallo, Ousmane,Koenig, Max
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p. 2414 - 2422
(2007/10/03)
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- Synthesis and investigation of phosphine ligands containing cationic guanidino functions in aqueous Heck reactions
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Phosphines 2 and 3 supplemented with strongly basic and hydrophilic guanidium functions were prepared for the first time. In combination with palladium acetate these ligands form active catalysts that promote an aqueous Heck reaction.
- Dibowski, Harald,Schmidtchen, Franz P.
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p. 2325 - 2330
(2007/10/02)
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- Process for the preparation of a butene
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Process for the preparation of 1-butene by dimerization of ethylene in the presence of an aprotic solvent and a catalytic system prepared by combining (a) a Pd compound, (b) an anion of an acid having a pKa = 1 N atoms which atoms bear no H atoms and in which compound each N atom is connected to the P atom by an organic bridging group containing >= 1 C atom in the bridge.
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