28225-52-7Relevant articles and documents
Valorization of furfural using ruthenium (II) complexes containing phosphorus-nitrogen ligands under homogeneous transfer hydrogen condition
Aguirre, Pedro,Aranda, Braulio,López, Vicente,Moya, Sergio A.,Parra-Melipán, Sebastián,Valdebenito, Gonzalo
, (2021/08/10)
In this paper, we report the catalytic activity of a series of ruthenium (II) complexes containing phosphorus-nitrogen bidentated (P-N) ligands in the hydrogenation of furfural via hydrogen transfer reaction using two hydrogen donor sources: 2-propanol in basic medium and formic acid under mild conditions. The results showed that all the ruthenium complexes studied are catalytically active in the hydrogenation of furfural by hydrogen transfer reaction; they showed 100% conversion with both hydrogen sources. However, selectivities towards the formation of furfuryl alcohol were better when formic acid was used. It was also found that the reaction studied in a basic medium competes with the Cannizzaro reaction, obtaining furfuryl alcohol and furoic acid in a 70/30 ratio; on the other hand, using formic acid as the hydrogen source yields furfuryl alcohol with 100% selectivity. Although formic acid can be used as a hydrogen source successfully. The optimal substrate/acid ratio was found to be 1:1, as a higher concentration of formic acid can cause catalyst decomposition. The yielded products, furfuryl alcohol and furoic acid, obtained from renewable sources, have multiple applications in the organic chemical industry, replacing or complementing similar fossil-derived products.
A general access to organogold(III) complexes by oxidative addition of diazonium salts
Huang, Long,Rominger, Frank,Rudolph, Matthias,Hashmi, A. Stephen K.
supporting information, p. 6435 - 6438 (2016/06/06)
At room temperature under mild photochemical conditions, namely irradiation with a simple blue light LED, gold(i) chloro complexes of both phosphane and carbene ligands in combination with aryldiazonium salts afford arylgold(iii) complexes. With chelating P,N-ligands cationic six- or five-membered chelate complexes were isolated in the form of salts with weakly coordinating counter anions that were brought in from the diazonium salt. With monodentate P ligands or N-heterocyclic carbene ligands and diazonium chlorides neutral arylgold(iii) dichloro complexes were obtained. The coordination geometry was determined by X-ray crystal structure analyses of representative compounds, a cis arrangement of the aryl and the phosphane ligand at the square planar gold(iii) center is observed.
Structural and photophysical study of copper iodide complex with P^N or P^N^P ligand
Liu, Zhiwei,Wei, Feng,Liu, Xiaochen,Bian, Zuqiang,Zhao, Yongliang,Huang, Chunhui
, p. 5338 - 5344 (2014/06/23)
Two P^N-type ligands, 8-(diphenylphosphino)quinoline (L1) and 2-[2-(diphenylphosphino)ethyl]pyridine (L2), and two P^N^P-type ligands, 2,6-bis((diphenylphosphino)methyl)pyridine (L3) and 2,6-bis((di-tert-butylphosphino)methyl)pyridine (L4), were synthesized to coordinate with copper iodide (CuI). As a result, CuI complexes with rich structures, such as discrete complexes with formulae of [Cu 2I2(L1)2] (5), [Cu3I 3(L2)2] (6), and [CuI(L3)] (7), and polymeric complexes with repeating units of [Cu2I2(L 4)] (8), and [Cu3I3(L4)] (9) were synthesized and characterized by single crystal X-ray diffraction. Besides the intriguing structures, these complexes showed rich photoluminescent properties, with emission colour that varied from blue to red and a photoluminescence quantum yield (PLQY) from 1.6 to 29.9% in the solid state. Molecular orbital calculation and experimental study showed that the emissions involve halide to ligand charge transfer (XLCT), metal to ligand charge transfer (MLCT), and/or cluster-centered (CC) excited states. This journal is the Partner Organisations 2014.
Quinaphos and dihydro-quinaphos phosphine-phosphoramidite ligands for asymmetric hydrogenation
Pullmann, Thomas,Engendahl, Barthel,Zhang, Ziyun,Hoelscher, Markus,Zanotti-Gerosa, Antonio,Dyke, Alan,Francio, Giancarlo,Leitner, Walter
supporting information; experimental part, p. 7517 - 7526 (2010/10/04)
New derivatives of the Quinaphos ligands and the related Dihydro-Quinaphos ligands based on the more flexible 1,2,3,4-tetrahydroquinoline backbone have been prepared and fully characterised. A general and straightforward separation protocol was devised, which allowed for the gram-scale isolation of the R a,Sc and Sa,Rc diastereomers. These new phos-phine-phosphoramidite ligands have been applied in the Rh-catalysed asymmetric hydrogenation of functionalised olefins with the achievement of excel-lent enantioselectivities (≥99%) in most cases and turnover frequency (TOF) values of up to ≥ 20000 h-1. These results substantiate the practical utility of readily accessible Quinaphostype ligands, which belong to the most active and selective category of ligands for Rh-catalysed hydrogenation known to date.
Methoxycarbonylation of olefins catalyzed by palladium complexes bearing P,N-donor ligands
Aguirre, Pedro A.,Lagos, Carolina A.,Moya, Sergio A.,Zuniga, Cesar,Vera-Oyarce, Cristian,Sola, Eduardo,Peris, Gabriel,Bayon, J. Carles
, p. 5419 - 5426 (2008/09/17)
The methoxycarbonylation of alkenes catalyzed by palladium(ii) complexes with P,N-donor ligands, 2-(diphenylphosphinoamino)pyridine (Ph 2PNHpy), 2-[(diphenylphosphino)methyl]pyridine (Ph 2PCH2py), and 2-(diphenylphosphino)quinoline (Ph 2Pqn) has been investigated. The results show that the complex [PdCl(PPh3)(Ph2PNHpy)]Cl or an equimolar mixture of [PdCl2(Ph2PNHpy)] and PPh3, in the presence of p-toluensulfonic acid (TsOH), is an efficient catalyst for this reaction. This catalytic system promotes the conversion of styrene into methyl 2-phenylpropanoate and methyl 3-phenylpropanoate with nearly complete chemoselectivity, 98% regioselectivity in the branched isomer, and high turnover frequency, even at alkene/Pd molar ratios of 1000. Best results were obtained in toluene-MeOH (3: 1) solvent. The Pd/Ph2PNHpy catalyst is also efficient in the methoxycarbonylation of cyclohexene and 1-hexene, although with lower rates than with styrene. Related palladium complexes [PdCl(PPh 3)L]Cl (L = Ph2PCH2py and Ph2Pqn) show lower activity in the methoxycarbonylation of styrene than that of the 2-(diphenylphosphinoamino)pyridine ligand. Replacement of the last ligand by (diphenylphosphino)phenylamine (Ph2PNHPh) or 2- (diphenylphosphinoaminomethyl)pyridine (Ph2PNMepy) also reduces significantly the activity of the catalyst, indicating that both the presence of the pyridine fragment as well as the NH group, are required to achieve a high performing catalyst. Isotopic labeling experiments using MeOD are consistent with a hydride mechanism for the [PdCl(PPh3)(Ph2PNHpy)]Cl catalyst. The Royal Society of Chemistry.
Synthesis of aryl phosphines via phosphination with triphenylphosphine by supported palladium catalysts
Wang, Yanchun,Lai, Chi Wai,Kwong, Fuk Yee,Jia, Wen,Chan, Kin Shing
, p. 9433 - 9439 (2007/10/03)
The palladium catalyzed phosphination of functionalized aryl bromides, triflates, and chlorides with triphenylphosphine to yield aryldiphenylphosphines was catalyzed by thermally stable palladium catalysts supported on charcoal and aluminia. The addition
Palladium-catalyzed phosphination of functionalized aryl triflates
Kwong, Fuk Yee,Lai, Chi Wai,Yu, Michael,Tian, Yuan,Chan, Kin Shing
, p. 10295 - 10305 (2007/10/03)
Catalytic user-friendly approach to the syntheses of various functionalized aromatic phosphines from their corresponding substituted aryl triflates and triarylphosphines was accomplished. This method is carried out in neutral media and compatible with man
Synthesis of aryl phosphines by phosphination with triphenylphosphine catalyzed by palladium on charcoal
Lai, Chi Wai,Kwong, Fuk Yee,Wang, Yanchun,Chan, Kin Shing
, p. 4883 - 4885 (2007/10/03)
The palladium-catalyzed phosphination of aryl bromides and triflates by phosphination with triphenylphines to yield aryl phosphines was catalyzed by the thermally stable catalyst palladium on charcoal.
A novel synthesis of functionalised tertiary phosphines by palladium catalysed phosphination with triarylphosphines
Kwong, Fuk Yee,Lai, Chi Wai,Tian, Yuan,Chan, Kin Shing
, p. 10285 - 10289 (2007/10/03)
The palladium catalysed Pd-aryl/P-aryl exchange was applied in the synthesis of various functionalised phosphines from their corresponding substituted aryl triflates using triarylphosphines as the phosphinating agents. This method tolerated many functional groups including ketone, aldehyde, ester, nitrile, methyl ether, pyridyl and chloride groups. (C) 2000 Elsevier Science Ltd.
Influence of various P/N and P/P ligands on the palladium-catalysed reductive carbonylation of nitrobenzene
Wehman, Petra,Van Donge, Hans M.A.,Hagos, Alay,Kamer, Paul C.J.,Van Leeuwen, Piet W.N.M.
, p. 183 - 193 (2007/10/03)
A series of bidentate phosphorus-nitrogen ligands was synthesised for the palladium-catalysed reductive carbonylation of nitrobenzene in order to combine the favourable influence of the phosphorus atom on the stability of the catalyst complex with the stimulating effect of the nitrogen atom on the catalytic activity. The nitrogen atom of the P/N ligand was either incorporated in an imine function, yielding the JV-(2′-diphenylphosphinobenzylidene)-R-amine ligands (R = phenyl, 4-chlorophenyl, 2,4-dimethoxyphenyl, 2,4-dimethylphenyl, tert-butyl), or in a heteroaromatic ring system which gave 2-(2′-(diphenylphosphino)ethyl)pyridine and 8-(diphenylphosphino)quinoline. Complexes of the type Pd(ligand)2(BF4)2 were prepared for these ligands. Additionally, a series of bidentate phosphorus ligands was tested: dppm, dppe, dppp, dppb, dppf, 1,2-bis(diphenylphosphino)benzene, 1,8-bis(diphenylphosphino)naphthalene, bis(2-diphenylphosphinophenyl)ether, and 9,9-dimethyl-4,6-bis(diphenylphosphino)xanthene. The P/N ligands containing the imine function did not yield any conversion of the nitrobenzene in combination with Pd. On the use of the second type of P/N ligand, moderately active palladium catalysts were obtained. This different behaviour is ascribed to the relatively low π *-level of the imine-containing ligands. Oxidation of the phosphorus donor atom by the nitro substrate inactivated the catalysts derived from the P/N ligands as well as from a series of P/P ligands. For the bidentate phosphorus ligands the bite angle and flexibility of the ligand turned out to be of crucial influence due to the different geometries required for the Pd(II) and Pd(0) intermediates of the catalytic cycle.
