Search results for "PALLADIUM"
showing 10 items of 956 documents
CCDC 628063: Experimental Crystal Structure Determination
2007
Related Article: L.Vigo, M.Risto, E.M.Jahr, T.Bajorek, R.Oilunkaniemi, R.S.Laitinen, M.Lahtinen, M.Ahlgren|2006|Cryst.Growth Des.|6|2376|doi:10.1021/cg060348r
tBuLi-Mediated One-Pot Direct Highly Selective Cross-Coupling of Two Distinct Aryl Bromides.
2015
A Pd-catalyzed direct cross-coupling of two distinct aryl bromides mediated by tBuLi is described. The use of [Pd-PEPPSI-IPr] or [Pd-PEPPSI-IPent] as catalyst allows for the efficient one-pot synthesis of unsymmetrical biaryls at room temperature. The key for this selective cross-coupling is the use of an ortho-substituted bromide that undergoes lithium-halogen exchange preferentially.
Solid state conformational and theoretical study of complexes containing the (CxN)Pd moiety (CxN = 2-(phenylazo)phenyl-C,N and its derivatives)
2003
Palladium complexes having the 2-(phenylazo)phenyl-C,N ligand exhibit a planar chelating ring with NN and N–C distances longer and shorter respectively than those found in trans-azobenzene. The ligand is not planar upon complexation, the mean angle between the phenyl ring and the chelating one found in the Cambridge Structural Database being of 45.6°. We have quantified and characterised the kind of distortion from planar coordination around metallic centers. The method employed makes use of two improper torsion angles, tetrahedral distortion being most frequently found in phenylazophenyl palladium complexes. Crystal structures of three succinimidate complexes having the title moiety are re…
Mono- and di-nuclear complexes of ortho-palladated and -platinated 4,4′-dimethylazobenzene with bis(diphenylphosphino)methane. More data on transphob…
2002
Abstract Complexes [Pd(κ2-R)(μ-Cl)]2 [κ2-R=κ2-C,N′-C6H3(NNC6H4Me-4′)-2-Me-5 (1)] and [Pd(κ1-R)Cl(κ1-dppm)(κ2-dppm)]TfO [dppm=bis(diphenylphosphino)methane (2)] have been used to prepare new palladium derivatives containing dppm. Thus, complex 1 reacts with one equivalent of dppm to afford [{Pd(κ2-R)Cl}2(μ-dppm)] (3) and with AgClO4 and dppm (1:2:2 molar ratios) to give [Pd(κ2-R)(κ2-dppm)]ClO4 (4·ClO4). The triflate salt of this complex (4·TfO) reacts with PPh3 to yield [Pd(κ1-R)(PPh3)(κ2-dppm)]TfO (5). Dinuclear complexes were obtained by reacting 2, (i) with [AuCl(PPh3)] or [AuCl(tht)] (tht=tetrahydrothiophene) (1:1, −60 °C) and (ii) with 1 (2:1) to give, respectively, [Pd(κ1-R)Cl(μ-dppm…
A new palladium(II)-catalyzed [3,3] aza-Claisen rearrangement of 3-allyloxy-5-aryl-1,2,4-oxadiazoles
2011
Abstract A new efficient palladium(II)-catalyzed [3,3] aza-Claisen, formal sigmatropic rearrangement of 3-allyloxy-5-aryl-1,2,4-oxadiazoles was developed. The mechanism was studied by analyzing the regiochemical and stereochemical course of the reaction. The results obtained indicated the intervention of a cationic pallada-cycle similar to the one postulated for the Cope rearrangement of 1,5-dienes.
Ex Vivo Tracking of Endogenous CO with a Ruthenium(II) Complex.
2017
[EN] A two-photon fluorescent probe based on a ruthenium(II) vinyl complex is capable of selectively detecting carbon monoxide in cells and ex vivo using mice with a subcutaneous air pouch as a model for inflammation. This probe combines highly selective and sensitive ex vivo detection of endogenous CO in a realistic model with facile, inexpensive synthesis, and displays many advantages over the widely used palladium-based systems.
Palladium-catalyzed Suzuki-Miyaura reaction involving a secondary sp3 carbon: studies of stereochemistry and scope of the reaction.
2007
Palladium-catalyzed C--C bond formation involving secondary sp3-hybridized carbon is described. These reactions occur with secondary 1-bromoethyl arylsulfoxides and different arylboronic acids, to produce the corresponding arylated sulfoxides in moderate to high yields and with complete stereospecificity. Despite the presence of beta hydrogens in the substrate, the competitive beta-hydride elimination is not a significant side reaction when coordinating solvents are used. The reported cross-coupling involves secondary C(sp3)--C(sp2) bond formation: this is the first time that a mechanistic study has been carried out with such substrates. The reaction proceeds with inversion of configuration…
Structural studies on 2-pyridyl complexes of the platinum triad metals. The crystal and molecular structure of the 2-pyridylium derivative trans-[PdC…
1991
Abstract In solution, the complex trans -[PdCl(C 5 H 4 N C 2 )(PMe 2 Ph) 2 ] ( 1 ) is in equilibrium with a small amount of the binuclear species [{PdCl(μ-C 5 H 4 N C 2 , N )(PMe 2 Ph)} 2 ] ( 2 ), which can be isolated upon recrystallization. The compound 1 is easily N-protonated by HClO 4 to the 2-pyridylium product trans -[PdCl(C 5 H 5 N C 2 )(PMe 2 Ph) 2 ]ClO 4 ( 3 ), which crystallizes in the orthorhombic space group P2 1 2 1 2 1 , with cell parameters a =15.761(3), b =14.369(2), c =11.132(2) A and Z =4. The X-ray crystal structure analysis of 3 , using 3744 observed reflections in the refinement and resulting in a final R value of 0.0298, shows that the coordination around palladium…
Application of palladium complexes bearing acyclic amino(hydrazido)carbene ligands as catalysts for copper-free Sonogashira cross-coupling
2015
Abstract Metal-mediated coupling of one isocyanide in cis-[PdCl2(CNR1)2] (R1 = C6H11 (Cy) 1, tBu 2, 2,6-Me2C6H3 (Xyl) 3, 2-Cl-6-MeC6H3 4) and various carbohydrazides R2CONHNH2 [R2 = Ph 5, 4-ClC6H4 6, 3-NO2C6H4 7, 4-NO2C6H4 8, 4-CH3C6H4 9, 3,4-(MeO)2C6H3 10, naphth-1-yl 11, fur-2-yl 12, 4-NO2C6H4CH2 13, Cy 14, 1-(4-fluorophenyl)-5-oxopyrrolidine-3-yl 15, (pyrrolidin-1-yl)C(O) 16, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propane-1-yl 17, EtNHC(O) 18] or sulfohydrazides R3SO2NHNH2 [R3 = Ph 19, 4-MeC6H4 20] led to a series of (hydrazido)(amino)carbene complexes cis-[PdCl2{ C (NHNHX) N(H)R1}(CNR1)]; X = COR2, SO2R3 (21–48, isolated yields 60–96%). All prepared species were characterized by elemental…
Solid-state cis–trans isomerism in bis(oxamato)palladate(ii) complexes: synthesis, structural studies and catalytic activity
2014
A new generation of bis(oxamato)palladate(II) monomeric complexes has been prepared by using N-2,6-dimethylphenyloxamate (2,6-Me2pma) as the ligand. Four alkaline salts of the complex, namely {[Na(H2O)]2trans-[PdII(2,6-Me2pma)2]}n (1a), {[Na4(H2O)2]cis-[PdII(2,6-Me2pma)2]2}n (1b), {[K4(H2O)3]cis-[PdII(2,6-Me2pma)2]2}n (2), {[Rb4(H2O)3]cis-[PdII(2,6-Me2pma)2]2}n (3) and {[Cs6(H2O)7]trans-[PdII(2,6-Me2pma)2]2cis-[PdII(2,6-Me2pma)2]}n·3nH2O (4), were obtained and structurally characterized by single crystal X-ray diffraction. Both the cis and trans stereoisomers of the [PdII(2,6-Me2pma)2]2− complex anion were isolated in the solid state, in a cation-dependent manner. The trans-isomer as the so…