Search results for "Phosphine"
showing 10 items of 618 documents
Gold(I) Complexes of Ferrocenyl Polyphosphines: Aurophilic Gold Chloride Formation and Phosphine-Concerted Shuttling of a Dinuclear [ClAu···AuCl] Fra…
2016
International audience; A smart steric control of the metallocene backbone in bis- and poly(phosphino)ferrocene ligands favors intramolecular aurophilic interactions between [AuCl] fragments in polynuclear gold(I) complexes. We synthesized and characterized by multinuclear NMR and X-ray diffraction analysis mono-, di-, and polynuclear gold complexes of constrained ferrocenyl diphosphines, which bear either bulky tert-butyl groups or more flexible siloxane substituents at the cyclopentadienyl rings. The complexes meso-1,1'-bis-(diphenylphosphino)-3,3'-di-tert-butylferrocene (4-m), rac-1,1'-bis[bis-(5-methy1-2-furyl)phosphino]-3,3'-di-tert-butyfferrocene (5-r), and rac-1,1'-bis ( diphenylphos…
Dioxomolybdenum(VI) complexes of hydrazone phenolate ligands - syntheses and activities in catalytic oxidation reactions
2021
Abstract The new cis-dioxomolybdenum (VI) complexes [MoO2(L2)(H2O)] (2) and [MoO2(L3)(H2O)] (3) containing the tridentate hydrazone-based ligands (H2L2 = N'-(3,5-di-tert-butyl-2-hydroxybenzylidene)-4-methylbenzohydrazide and H2L3 = N'-(2-hydroxybenzylidene)-2-(hydroxyimino)propanehydrazide) have been synthesized and characterized via IR, 1H and 13C NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction analysis. The catalytic activities of complexes 2 and 3, and the analogous known complex [MoO2(L1)(H2O)] (1) (H2L1 = N'-(2-hydroxybenzylidene)-4-methylbenzohydrazide) have been evaluated for various oxidation reactions, viz. oxygen atom transfer from dimethyl sulfoxide to t…
Performances of symmetrical achiral ferrocenylphosphine ligands in palladium-catalyzed cross-coupling reactions: A review of syntheses, catalytic app…
2007
Abstract Ferrocene derivatives bearing donor atoms led to the generation of several classes of metallo-ligands, which collectively show an impressive diversity of applications, especially in metal-catalyzed modern organic reactions. Based on the impetus provided by the use of the diphosphine 1,1′-bis(diphenylphosphino)ferrocene (dppf) the investigations directed towards the synthesis of new ferrocenylphosphines remain of fundamental and industrial interest. The present review aims to describe the performances in palladium-catalyzed cross-coupling reactions of symmetrical achiral ferrocenylphosphine ligands, mainly diphosphines. We specifically choose to restrict our review efforts to these …
Synthesis of new cationic donor-stabilized phosphenium adducts and their unexpected P-substituent exchange reactions
2008
The reaction between two 1,3-dialkylimidazolium-2-carboxylates 1a and 1b and two different dichlorophosphines (RPCl(2), with R = Ph and NEt(2)) led to new donor-stabilized phosphenium adducts. When the reaction was performed with the 1,3-dimethylimidazolium-2-carboxylate 1a and PhPCl(2) in a 2:1 ratio, the phosphine 4a, bearing two imidazolium moieties, was obtained and led to 5a, after an anion exchange reaction with KPF(6), the latter being fully characterized by an X-ray structure analysis. In similar conditions, the bis-imidazolium phosphine or phosphene-di-ium, 4b, which is analogous to 4a, has been obtained by the addition of PhPCl(2) to the 1-dodecyl-3-methylimidazolium-2-carboxylate…
G2(MP2) molecular orbital study of the substituent effect in the H3BPH3−nFn (n=0–3) donor–acceptor complexes
2000
Abstract The complexation energies of H3BPH3−nFn (n=0–3) and the proton affinities of PH3−nFn compounds have been investigated at the G2(MP2) level of theory. G2(MP2) results show that the successive fluorine substitution on the phosphine increases the stability of H3BPH3−nFn complexes although the basicity of the PH3−nFn ligands reduces with this substitution. The NBO partitioning scheme shows that this stability was related to the hyperconjugation effect. It proves also that the shortening of the P–H and P–F bond lengths, upon complexation, is due to an increasing `s' character in these bonds.
INSERTION OF ISOCYANIDES INTO THE PALLADIUM CARBON BOND OF C-2-PALLADATED HETEROCYCLES - SYNTHESIS OF TRANS-[PDCL(C(RN)=NR) (PPH3)2] COMPLEXES (RN = …
1985
The titles complexes trans-[PdCl{C(RN)NR}(PPh3)2] (RN = 2-pyridyl (2-py), R = p-C6H4OMe, Me; RN = 2-pyrazyl (2-pyz), R = p-C6H4OMe) can be prepared by reaction of the N-protonated compounds, cis-[PdCl2(RNH)(PPh3] (RNH = 2-pyridylium (2-pyH) or 2-pyrazylium (2-pyzH) group), with PPh3, followed by addition of the isocyanide CNR and deprotonation with triethylamine, in a molar ratio Pd/PPh3/CNR/NEt3 of 1/1/1/1.1. The reaction sequence involves the successive formation of the cationic intermediates trans-[PdCl(RNH)(PPh3)2]+, trans-[Pd(RNH)(CNR)(PPh3)2]2+ and trans-[Pd(RN)(CNR)(PPh3)2]+, which were isolated and characterized as perchlorate salts for RN = 2-pyridyl. In the final step the coordin…
Preparation and protonation of 2-pyrimidyl- and 2-pyrazylpalladium(II) complexes
1985
Abstract The oxidative addition of 2-chloropyrimidine or 2-chloropyrazine to [Pd(PPh 3 ) 4 ] yields a mixture of trans -[PdCl(C 4 H 3 N 2 - C 2 )(PPh 3 ) 2 ] (I) and [PdCl(μ-C 4 H 3 N 2 - C 2 , N 1 )(PPh 3 (II) (C 4 H 3 N 2 = 2-pyrimidyl or 2-pyrazyl group). The mononuclear complexes I are quantitatively converted into the binuclear species II upon treatment with H 2 O 2 . The reaction of II with HCl gives the N -monoprotonated derivatives cis -[PdCl 2 (C 4 H 4 N 2 - C 2 )(PPh 3 )] (III), from which the cationic complexes trans -[PdCl(C 4 H 4 N 2 - C 2 )(L) (L = PPh 3 , IV; PMe 2 Ph, V; PEt 3 , VI) can be prepared by ligand substitution reactions. Reversible proton dissociation occurs in so…
Catalytic and anticancer activities of sawhorse-type diruthenium tetracarbonyl complexes derived from fluorinated fatty acids
2013
The reaction of fluorinated fatty acids, perfluorobutyric acid (C3F7CO2H), and perfluorododecanoic acid (C11F23CO2H), with dodecacarbonyltriruthenium (Ru3(CO)12) under reflux in tetrahydrofuran, followed by addition of two-electron donors (L) such as pyridine, 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane, or triphenylphosphine, gives stable diruthenium complexes Ru2(CO)4(μ2-η2-O2CC3F7)2(L)2 (1a, L = C5H5N; 1b, L = PTA; 1c, L = PPh3) and Ru2(CO)4(μ2-η2-O2CC11F23)2(L)2 (2a, L = C5H5N; 2b, L = PTA; 2c, L = PPh3). The catalytic activity of the complexes for hydrogenation of styrene under supercritical carbon dioxide has been assessed and compared to the analogous triphenylphosphine complexes w…
Converging and Diverging Synthetic Strategies to Tetradentate (N,N′)-Diaminomethyl,(P,P′)-Ferrocenyl Ligands: Influence of tert-Butyl Groups on Ferro…
2015
Hexasubstituted hybrid tetradentate (N,N′,P,P′)-ferrocenes bearing phosphino and aminomethyl groups, plus hindering tert-butyl moieties, were synthesized by using two different strategies: a “diverging” synthesis involving successive functionalization of preformed di-tert-butylated ferrocene and a “converging” assembly of the species from appropriately substituted cyclopentadienyl rings. While the new cyclopentadienyl salts formed are of interest, their assembly with iron dichloride used as a “converging” way to produce tetradentate ferrocene ligands presented several drawbacks. Conversely, the synthesis of new tert-butylated (aminomethyl)ferrocene derivatives was found convenient to furthe…
Unique copper ion catalyzed hydrolytic cleavage of C–N(2) bond of thiosemicarbazide
2006
Abstract For the first time, stable but coordinatively unsaturated Cu(II) complexes [Cu(2,2′-bpy)X2] · xH2O (X = ClO4, NO3, CH3COO and 2,2′-bpy = 2,2′-bipyridyl) have been found to promote the hydrolysis of C–N(2) bond of thiosemicarbazide (tsc) at 25 °C and at neutral pH yielding monomeric [Cu(2,2′-bpy)(NCS)2]. Direct reaction between [Cu(2,2′-bpy)2]Cl2 · 6H2O, KSCN and CuCl2 results in polymeric [Cu(2,2′-bpy)(NCS)2]n [1] [Inorg. Chim. Acta. 286 (1999) 108]. Similarly tsc is cleaved by Cu(I) complex [Cu(ϕ3P)2(CH3CN)2]ClO4 [ϕ3P = triphenylphosphine] which itself is converted into dimeric [Cu(ϕ3P)2(NCS)]2.