- [Au3Ge18]5 - A gold-germanium cluster with remarkable Au-Au interactions
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Gold linkers: The first soluble gold-germanium cluster was obtained from the reaction of [Au(PPh3)Cl] and K4Ge9. The formation of the gold complex [Ge9Au3Ge9] 5- (see picture) shows also an exciting result for gold chemistry: linearly coordinated gold atoms and the characteristics of aurophilic contacts between the metal atoms can be observed in the presence of polyanionic Zintl ions. (Figure Presented).
- Spiekermann, Annette,Hoffmann, Stephan D.,Kraus, Florian,Faessler, Thomas F.
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- Bis1N'>gold(III) Complexes. Crystal and Molecular Structure of Bis1N'>gold(III) Tetrachloroaurate
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The reaction between and gave the gold(III) complex which reacts with AgClO4 to form ClO4.Addition of X (X=Cl), NaX (X=Br), or KX (X=I, CN or O2CMe), to the cationic complex leads to the corresponding neutral complexes .Reaction of ClO4 with -, leads to .By reacting the neutral acetato-complex with ClO4 (Hpy=pyridinium), ClO4 is prepared.The crystal structure of has been determined and shows that the cation has a square-planar co-ordination with two cis-nitrogen and the two cis-carbon atoms bonded to gold.
- Vicente, Jose,Chicote, Maria-Teresa,Bermudez, Maria-Dolores,Solans, Xavier,Font-Altaba, Manuel
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- Gold(I)-phosphine-N-heterocycles: Biological activity and specific (ligand) interactions on the C-terminal HIVNCp7 zinc finger
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The syntheses and the characterization by chemical analysis, 1H and 31P NMR spectroscopy, and mass spectrometry of a series of linear triphenylphosphine gold(I) complexes with substituted N-heterocycle ligands (L), [(PPh3)Au(I)(L)]+, is reported. The reaction of [(PPh3)Au(L)]+ (L = Cl- or substituted N- heterocyclic pyridine) with the C-terminal (Cys3His) finger of HIVNCp7 shows evidence by mass spectrometry (ESI-MS) and 31P NMR spectroscopy of a long-lived {(PPh3)Au}-S-peptide species resulting from displacement of the chloride or pyridine ligand by zinc-bound cysteine with concomitant displacement of Zn2+. In contrast, reactions with the Cys2His2 finger-3 of the Sp1 transcription factor shows significantly reduced intensities of {(PPh3)Au} adducts. The results suggest the possibility of systematic (electronic, steric) variations of carrier group PR3 and leaving group L as well as the nature of the zinc finger in modulation of biological activity. The cytotoxicity, cell cycle signaling effects, and cellular accumulation of the series are also reported. All compounds display cytotoxicity in the micromolar range upon 96 h continuous exposure to human tumor cells. The results may have relevance for the reported inhibition of viral load in simian virus by the gold(I) drug auranofin.
- Abbehausen, Camilla,Peterson, Erica J.,De Paiva, Raphael E. F.,Corbi, Pedro P.,Formiga, Andre L. B.,Qu, Yun,Farrell, Nicholas P.
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- Dynamic covalent assembly and disassembly of nanoparticle aggregates
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The quantitative assembly and disassembly of a new type of dynamic covalent nanoparticle (NP) building block is reported. In situ spectroscopic characterization reveals constitutionally adaptive NP-bound monolayers of boronate esters. Ditopic linker molecules are used to produce covalently connected AuNP assemblies, displaying open dendritic morphologies, and which, despite being linked by covalent bonds, can be fully disassembled on application of an appropriate chemical stimulus.
- Borsley, Stefan,Kay, Euan R.
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- Synthesis, crystal structure and a spectroscopic study of bis(triphenylphosphine)gold(I)+ TCNQ-
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The complex of the bis(triphenylphosphine)gold(I) cation and the radical anion of 2,2-(2,5-cyclohexadiene-1,4-diylidene)bispropanedinitrile, (TCNQ), has been prepared and characterized by spectroscopic and X-ray crystallographic methods. The solid state structure consists of the linear (P-Au-P) cation bis(triphenylphosphine)gold(I) and the approximately planar radical anion of TCNQ. The bond lengths are: Au-P 2.300(2); P-C 1.800(11), 1.789(11), 1.800(11); C≡N 1.175(16), 1.128(16). The infrared spectrum of the complex exhibits bands at 2176 and 2150 cm-1 in the nitrile region. The electron spin resonance spectrum of this compound, in benzene, is consistent with a structure in which the TCNQ radical anion is symmetrically oriented about the bis(triphenylphosphine)gold(I) cation. The hyperfine coupling constants are: aN = 0.981, aH = 1.379, aP = 0.095 gauss.
- Baenziger,Bennett,Soboroff,O'Donnell,Doyle
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- Gold nanoparticles on wool in a comparative study with molecular gold catalysts
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The catalytic activity of gold chloride nanoparticles is compared to the activity of two molecular gold(I) chloride phosphine complexes for the addition of methanol to 3-hexyne. The phosphines are triphenylphosphine and the bispidinone related bulky 6,8-bis-(4-dimethylamino-phenyl)-3-methyl-9-oxo-7- phenyl-3-aza-7-phospha-bicyclo[3.3.1]nonan-1,5-dicarboxylic acid dimethyl ester. Use of the bulky ligand made the addition reaction selective towards the enol product, meaning that no addition of methanol or water to alkenes, which were produced during the reaction, occurred. In contrast, use of triphenylphosphine gold(I) chloride resulted in the synthesis of a variety of products. The phosphines decomposed during reaction leading to the formation of gold nanoparticles, which were found to be catalytically inactive. Artificially produced gold nanoparticles also proved to be inactive. In contrast, gold chloride nanoparticles deposited on wool were active comparable to the gold phosphine-containing catalysts tested previously. Overall activities observed were low compared to results from the literature suggesting that the operating conditions chosen could be optimised.
- Borrmann, Thomas,Lim, Teck Hock,Cope, Hannah,Lucas, Kerstin,Lorden, Michael
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- Synthesis and reactivity of [Au(2-CH2-6-RC5H3N)(PPh3)] (R = H, Me). X-ray structure of [Ag{Au(2-CH2-6-MeC5H3N)(PPh3)} 2][ClO4]
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The reaction of Li(2-CH2-6-RC5H3N) with [AuCl(PPh3)] leads to the mononuclear complexes [Au(2-CH2-6-RC5H3N)(PPh3)] (R = H, Me). These react further with other copper, silver or gold compounds to give heteronuclear derivatives, [M{Au(2-CH2-6-RC5H3N)(PPh3)} 2][X] (M = Cu, X = PF6 or M = Ag, X = ClO4), or the dinuclear complex [Au(2-CH2-6-MeC5H3N)]2. The crystal structure of [Ag{Au(2-CH2-6-MeC5H3N)(PPh3)} 2][ClO4] has been determined by X-ray diffraction studies and shows short interactions between the gold and silver centres.
- Casas, J. Enrique,Gimeno, M. Concepcion,Jones, Peter G.,Laguna, Antonio,Laguna, Mariano
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- SYNTHESIS OF ORGANOGOLD(1+) COMPOUNDS BY DIRECT AURATION
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Organogold(1+) compounds have been synthesized by direct auration of cyclopentadiene, cyanoacetic ester and malonitrile with (Ph3PAu)3O+BF4-.An X-ray structural study (λ Mo, 5062 reflections, R = 0.039) of bis(triphenylphosphinegold)malonitrile has been carried out (monoclinic, a = 12.055(6), b = 14.086(5), c = 20.466(12) Angstroem, β = 90.32(4) deg, space group P21/c, Z = 4).The Au-Au bond length is 2.912(1) Angstroem.
- Smyslova, E. I.,Perevalova, E. G.,Dyadchenko, V. P.,Grandberg, K. I.,Slovokhotov, Yu. L.,Struchkov, Yu. T.
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- Fibrous nano-silica containing immobilized Ni@Au core-shell nanoparticles: A highly active and reusable catalyst for the reduction of 4-nitrophenol and 2-nitroaniline
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A novel, dandelion-like fibrous nano-silica catalyst (Ni@Au/KCC-1) has been synthesized by modifying fibrous nano-silica (KCC-1) with Ni@Au core-shell nanoparticles (NPs). KCC-1 was prepared using a hydrothermal method and has a dandelion-like shape, high surface area, and easy accessibility; KCC-1 can also be functionalized with 3-mercaptopropyltriethoxysilane. The mercaptopropyl groups on the fibers act as robust anchors for the immobilization of Ni@Au NPs, thus preventing the aggregation of the Ni@Au NPs. We investigated the catalytic performance of the Ni@Au/KCC-1 nanocatalyst by reducing 4-nitrophenol to 4-aminophenol in the presence of NaBH4 as a probe reaction. The resulting Ni@Au/KCC-1 nanocatalyst exhibited superior catalytic activity to Ni@Au NPs, which may be attributed to the high accessibility of the KCC-1 support material. To some extent, it also may be due to the poor aggregation of Ni@Au NPs on the KCC-1 nano-silica support. The Ni@Au/KCC-1 nanocatalyst also showed high catalytic activity when used to reduce 2-nitroaniline. It is noteworthy that using Ni cores to fabricate the active sites Ni@Au NPs resulted in a lower amount of Au needed than is typical, because most of the Au-NPs catalyzed reactions occur on the surfaces of the NPs. In addition, the Ni cores give the Ni@Au/KCC-1 nanocatalyst superparamagnetic properties that increase its ease of recovery by a powerful magnet, allowing for it to be reused. The abovementioned approach based on fibrous KCC-1 and Ni@Au NPs provided a useful platform for the fabrication of noble-metal-based nanocatalysts with easy accessibility and a low cost, which may allow for an efficient green alternative for various catalytic reductions.
- Le, Xuanduong,Dong, Zhengping,Zhang, Wei,Li, Xinlin,Ma, Jiantai
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- Thiol-functionalized undecagold clusters by ligand exchange: Synthesis, mechanism, and properties
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Ligand exchange of phosphine-stabilized undecagold precursor particles, Au11(PPh3)8Cl3, with ω-functionalized thiols provides a convenient and general approach for the rapid preparation of large families of thiol-stabilized, subnanometer (d CORE ～ 0.8 nm) particles. The approach permits rapid incorporation of specific functionality into the stabilizing ligand shell, is tolerant of a wide range of functional groups, and provides convenient access to new materials inaccessible by other methods. Mechanistic studies and trapping experiments give insight into the progression of the ligand exchange, providing evidence that the core size of the phosphine-stabilized undecagold precursor particles is preserved during ligand exchange. The optical properties of the thiol-stabilized nanoparticles depend strongly on the composition of the ligand shell, and a series of studies suggests that this dependence is a result of the ligand shell's influence on the electronic structure of the particle core, as opposed to a structural change within the nanoparticle core.
- Woehrle, Gerd H.,Hutchison, James E.
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- New Acridine Thiourea Gold(I) Anticancer Agents: Targeting the Nucleus and Inhibiting Vasculogenic Mimicry
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Two new 1-acridin-9-yl-3-methylthiourea Au(I) DNA intercalators [Au(ACRTU)2]Cl (2) and [Au(ACRTU) (PPh3)]PF6 (3) have been prepared. Both complexes were highly active in the human ovarian carcinoma cisplatin-sensitive A2780 cell line, exhibiting IC50 values in the submicromolar range. Compounds 2 and 3 are also cytotoxic toward different phenotypes of breast cancer cell lines MDA-MB-231 (triple negative), SK-BR-3 (HER2+, ERα-, and ERβ-), and MCF-7 (ER+). Both complexes induce apoptosis through activation of caspase-3 in vitro. While inhibition of some proteins (thiol-containing enzymes) seems to be the main mechanism of action for cytotoxic gold complexes, 2 and 3 present a DNA-dependent mechanism of action. They locate in the cell nucleus according to confocal microscopy and transmission electronic microscopy. The binding to DNA resulted to be via intercalation as shown by spectroscopic methods and viscometry, exhibiting a dose-dependent response on topoisomerase I mediated DNA unwinding. In addition, 2 and 3 exhibit potent antiangiogenic effects and are also able to inhibit vasculogenic mimicry of highly invasive MDA-MB-231 cells.
- Pérez, Sergio A.,De Haro, Concepción,Vicente, Consuelo,Donaire, Antonio,Zamora, Ana,Zajac, Juraj,Kostrhunova, Hana,Brabec, Viktor,Bautista, Delia,Ruiz, José
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- A novel method of introducing the Au2(PR3 ) 2 (R = Ph, OMe) unit into metal clusters X-ray structures of three complexes containing Au2Ru3 cores and of Ru6C(μ-CO) 2(CO) 14{Au(PPh3)}2
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The complexes Ru3(μ3-C6H3R){μ-P(C6H4R-3)2}2(CO)6{Au2(PPh3)2} (R = H (2), Me), Ru3(μ3-PPhCH2PPh(C6H4-2)}(CO)8-{Au2(PR3)2} (R = Ph, OMe (5)), Ru3(μ3-NPh)n(CO)10-n{Au2(PPh3)2} (n = 1 (6), 2) and Ru3(μ3-S)2(CO)8{Au2(PPh3)2} have been obtained from reactions between [O{Au(PR3)}3]+ (R = Ph, OMe) and the 'parent' Ru3 clusters; X-ray structural studies of 2, 5 and 6 show that a CO group has been replaced by an Au2(PR3)2 fragment. In contrast, the two Au(PPh3) groups bridge opposite Ru-Ru bonds in Ru6C(μ-CO)2(CO)14{Au(PPh3)}2 (9; X-ray structure). The known complexes Os3(CO)11{Au2(PPh3)2}, and Os3H2-n(CO)10-{Au(PPh3)}n (n = 1, 2) were obtained from Os3(CO)12 and Os3H2(CO)10 respectively.
- Bruce, Michael I.,Horn, Ernst,Humphrey, Paul A.,Tiekink, Edward R.T.
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- Radical-involved photosynthesis of AuCN oligomers from Au nanoparticles and acetonitrile
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We show here the first radical route for the direct photosynthesis of AuCN oligomers with different sizes and shapes, as evidenced by TEM observations, from an Au nanoparticle/benzaldehyde/CH3CN ternary system in air under UV-light irradiation. This photochemical route is green, mild, and universal, which makes itself distinguishable from the common cyanidation process. Several elementary reaction steps, including the strong C-C bond dissociation of CH3CN and subsequent ?CN radical addition to Au, have been suggested to be critical in the formation of AuCN oligomers based on the identification of ?CN radical by in situ EPR and the radical trapping technique, and other reaction products by GC-MS and 1H NMR, and DFT calculations. The resulting solid-state AuCN oligomers exhibit unique spectroscopic characters that may be a result of the shorter Au-Au distances (namely, aurophilicity) and/or special polymer-like structures as compared with gold cyanide derivatives in the aqueous phase. The nanosized AuCN oligomers supported on mesoporous silica showed relatively good catalytic activity on the homogeneous annulation of salicylaldehyde with phenylacetylene to afford isoflavanones employing PBu3 as the cocatalyst under moderate conditions, which also serves as evidence for the successful production of AuCN oligomers.
- Li, Renhong,Kobayashi, Hisayoshi,Tong, Jiawei,Yan, Xiaoqing,Tang, Yu,Zou, Shihui,Jin, Jiabin,Yi, Wuzhong,Fan, Jie
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- Phosphole-modified poly(thiophene)s: Unique postfunctionalizable conjugated polymers that sense elemental chalcogenides
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(Chemical Equation Presented) Bulk response: Following the development of conjugated polymers that sense ions or neutral molecules, the first π-conjugated polymer which is capable of detecting elemental chalcogens is presented. Individual reactions at the
- Sebastian, Manuel,Hissler, Muriel,Fave, Claire,Rault-Berthelot, Joelle,Odin, Christophe,Reau, Regis
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- Induced Circular Dichroism in Phosphine Gold(I) Aryl Acetylide Urea Complexes through Hydrogen-Bonded Chiral Co-Assemblies
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Phosphine gold(I) aryl acetylide complexes equipped with a central bis(urea) moiety form 1D hydrogen-bonded polymeric assemblies in solution that do not display any optical activity. Chiral co-assemblies are formed by simple addition of an enantiopure (metal-free) complementary monomer. Although exhibiting an intrinsically achiral linear geometry, the gold(I) aryl acetylide fragment is located in the chiral environment displayed by the hydrogen-bonded co-assemblies, as demonstrated by induced circular dichroism (ICD). Phosphine gold(I) aryl acetylide complexes equipped with a central bis(urea) moiety form hydrogen-bonded supramolecular polymers in solution that do not display any optical activity. Co-assembly with a chiral (metal-free) co-monomer is used to place the intrinsically achiral gold(I) aryl acetylide fragment in a chiral environment, as demonstrated by induced circular dichroism (ICD).
- Dubarle-Offner, Julien,Moussa, Jamal,Amouri, Hani,Jouvelet, Benjamin,Bouteiller, Laurent,Raynal, Matthieu
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- ETHYNYLGOLD(I) COMPLEXES
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Reactions between R3PAuCl, NaOEt, and HCCR' under mild conditions produce R3PAuCCR' in excellent yield.When R' = H, a second step leading to the formation of R3PAuCCAuPR3 can take place.Exchange reactions of ethynyl for chloride between the ethynylgold complexes and HgCl2, cis-, cis-, and R 3PAuCl have been monitored, revealing R3PAuCCR' to be useful alkynylating agents.In the reaction with cis-, the first substitution step is non-specific.
- Cross, Ronald J.,Davidson, Michael F.,McLennan, Alistair J.
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- Oxidative Addition to Gold(I) by Photoredox Catalysis: Straightforward Access to Diverse (C,N)-Cyclometalated Gold(III) Complexes
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Herein, we report the oxidative addition of aryldiazonium salts to ligand-supported gold(I) complexes under visible light photoredox conditions. This method provides experimental evidence for the involvement of such a process in dual gold/photoredox-catalyzed reactions and delivers well-defined (C,N)-cyclometalated gold(III) species. The remarkably mild reaction conditions and the ability to widely vary the ancillary ligand make this method a potentially powerful synthetic tool to access diverse gold(III) complexes for systematic studies into their properties and reactivity. Initial studies show that these species can undergo chloride abstraction to afford Lewis acidic dicationic gold(III) species.
- Tlahuext-Aca, Adrian,Hopkinson, Matthew N.,Daniliuc, Constantin G.,Glorius, Frank
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- Behavior of dodecahydro-closo-dodecaborate anion B12H 12 2- in reaction with Au(Ph3P)Cl
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The reaction of the anion B12H 12 2- with [Au(Ph3P)Cl] in acetonitrile was studied. The nature of the initial cation of the closo-dodecaborate and the reagent ratio was shown to affect complexing. The X-ray structures of compounds Au(Ph3P) 2[AgB12H12] (I) and [Au9(Ph 3P)8]B24H23 (II) were determined. Complex I is the first example where B12H 12 2- is coordinated to silver(I) atoms in the face coordination mode. In complex II, B12H 12 2- is oxidized to the dimeric trianion B24H 23 3- where the two icosahedra are linked by a B-H-B′ bridge.
- Avdeeva,Malinina,Belousova,Goeva,Polyakova,Kuznetsov
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- Influence of the Linker Length on the Cytotoxicity of Homobinuclear Ruthenium(II) and Gold(I) Complexes
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Dinuclear metal complexes have emerged as a promising class of anticancer compounds with the ability to cross-link biomolecular targets. Here, we describe two novel series of phosphine-linked dinuclear ruthenium(II) p-cymene and gold(I) complexes, in which the length of the connecting poly(ethylene glycol) chain has been systematically modified. The impact of the multinuclearity, lipophilicity, and linker length on the antiproliferative activity of the compounds on tumorigenic (A2780 and A2780cisR) and nontumorigenic (HEK-293) cell lines was assessed. The dinuclear ruthenium(II) complexes were considerably more cytotoxic than their mononuclear counterparts, and a correlation between the lipophilicity of the linker and the cytotoxicity was observed, whereas the cytotoxicity of the gold(I) series is independent of these factors.
- Batchelor, Lucinda K.,Pǎunescu, Emilia,Soudani, Mylène,Scopelliti, Rosario,Dyson, Paul J.
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- Anionic N-Heterocyclic Carbene Complexes of Gold(I) as Precatalysts for Silver-Free Cycloisomerization of Enynes
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The anionic malonate-derived N-heterocyclic carbene maloNHC readily and efficiently reacts with AuCl(tht) to generate the corresponding anionic gold(I) complexes of type [(maloNHC)AuCl](M). A stoichiometric reaction of these complexes with triphenylphosphine affords the zwitterionic complex [(maloNHC)Au(PPh3)]. Although totally insoluble in the reaction medium, the [(maloNHC)AuCl](M) salts were shown to be suitable precatalysts for the cycloisomerization of 1,6-enynes through the in situ generation of soluble zwitterionic catalytic species of the type [(maloNHC)Au]. The anionic maloNHC-gold(I) complexes, synthesized as their Li+, K+, and Et4N+ salts, were fully characterized and used as precatalysts in the silver-free Au-catalyzed cycloisomerization reaction of 1,6-enynes. It was revealed that the nature of the countercation has a strong influence on the catalyst efficiency. The potassium salt appeared to be the best catalyst affording yields of up to 99?%.
- Bastin, Stéphanie,Barthes, Cécile,Lugan, No?l,Lavigne, Guy,César, Vincent
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- Steric control of the in/out sense of bridgehead substituents in macrobicyclic compounds: Isolation of new "crossed chain" variants of in/out isomers
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Isomers of the cage like dibridgehead diphosphine P((CH2)14)3P (1) are treated with Ph3PAu(2,6-C6H3(Trip)2) (2 equiv.; Trip = 2,4,6-C6H2(iPr)3). With out,out-1, workup gives out,out-1·(Au(2,6-C6H3(Trip)2))2 (46%), as confirmed by a crystal structure. With in,out-1, crystallization affords not in,out-1·(Au(2,6-C6H3(Trip)2))2, but rather an out,out isomer in which one of the (CH2)14 segments threads through the macrocycle formed by the other two. Implications for mechanisms of interconversion of in,out isomers are analyzed.
- Stollenz, Michael,Taher, Deeb,Bhuvanesh, Nattamai,Reibenspies, Joseph H.,Baranová, Zuzana,Gladysz, John A.
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- Structural evolution of atomically precise thiolated bimetallic [Au 12+ nCu32(SR)30+ n]4- (n = 0, 2, 4, 6) Nanoclusters
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A series of all-thiol stabilized bimetallic Au-Cu nanoclusters, [Au 12+nCu32(SR)30+n]4- (n = 0, 2, 4, 6 and SR = SPhCF3), are successfully synthesized and characterized by X-ray single-crystal analysis and density functional theory (DFT) calculations. Each cluster consists of a Keplerate two-shell Au12@Cu20 core protected by (6 - n) units of Cu2(SR)5 and n units of Cu2Au(SR)6 (n = 0, 2, 4, 6) motifs on its surface. The size and structural evolution of the clusters is atomically controlled by the Au precursors and countercations used in the syntheses. The clusters exhibit similar optical absorption properties that are not dependent on the number of surface Cu2Au(SR)6 units. Although DFT suggests an electronic structure with an 18-electron superatom shell closure, the clusters display different thermal stabilities. [Au12+nCu32(SR) 30+n]4- clusters with n = 0 and 2 are more stable than those with n = 4 and 6. Moreover, an oxidation product of the clusters, [Au 13Cu12(SR)20]4-, is structurally identified to gain insight into how the clusters are oxidized.
- Yang, Huayan,Wang, Yu,Yan, Juanzhu,Chen, Xi,Zhang, Xin,H?kkinen, Hannu,Zheng, Nanfeng
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- Tuneable reactivity with PPh3 and SnX2 of four- and five-coordinate Pd(ii) and Pt(ii) complexes containing polyphosphines
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The reactivity of the unusual d8 trigonal-bipyramidal systems [MX(PP3)]X (X = Cl: M = Pd(1a), Pt(2a); X = Br: M = Pd(3a), Pt(4a); X = I: M = Pd(5a), Pt(6a); PP3 = tris[2-(diphenylphosphino)ethyl] phosphine) in CHCl3-CH3OH, the square-pyramidal compounds [MCl(NP3)]Cl (M = Pd(7a); Pt(8a); NP3 = tris[2-(diphenylphosphino)ethyl]amine) in CD3OD-DMF and the distorted square-planar mononuclear [MX(PNP)]X (M = Pd: X = Cl(10a); M = Pt: X = I(10b); PNP = bis[2-(diphenylphosphino)ethyl]amine) and the heteronuclear [PdAu 2X4(PP3)] [X = I(9a), Cl(14a), Br(15a)] and [MAuX2(PP3)]X [M = Pd: X = Cl(16a); M = Pt: X = Cl(17a), Br(18a)] species in CDCl3 with PPh3 + SnX2 has been explored to establish the factors that influence the nature of the products. With the mononuclear precursors the course of the reaction is strongly dependent on the tripodal or linear arrangement of the polydentate ligand and in the former case on the halogen. Thus, while for chlorides (1a-2a, 7a-8a) and bromides (3a-4a) the reaction led to the trigonal-bipyramidal compounds [M(SnCl3)(AP3)][SnCl3] [A = P: M = Pd(1), Pt(2); A = N: M = Pd(7), Pt(8)], [MBr(PP3)][SnBr3] [M = Pd(4), Pt(6)] containing M-Sn and M-Br bonds, respectively, for iodides (5a-6a) resulted in the unknown neutral square-planar compounds [MI2(PP(PO) 2)(SnI2)2] [M = Pd(9) and Pt(10)] bearing two dangling PO-SnI2 units and P2MI2 environments. However, complexes of the type [PtCl(PP2PO)X]X′ [X = SnCl 2, X′ = [SnCl3]-(11)] and [M(PP(PO) 2)2X4]X′2 [X = SnCl 2, X′ = [SnCl3]-: M = Pd(12), Pt(13)] showing PO-SnCl2 arms were obtained by direct reaction of [PtCl(PP2PO)]Cl (11a) and [M(PP(PO)2)2]Cl 2 [M = Pd(12a), Pt(13a)] with SnCl2 in CH3OH. Although complex 9 was also prepared by interaction of the heteronuclear iodide 9a with PPh3 + SnI2 in CDCl3, the use of the neutral and ionic heteronuclear chlorides and bromides (14a-18a) as starting materials afforded the distorted square-planar ionic systems [MAuX′(PP3)(PPh3)][SnX3]2 [M = Pd: X = Cl, X′ = SnCl3-(14); X = Br, X′ = SnBr3-(15); M = Pt: X = Cl, X′ = SnCl 3-(17); X = Br, X′ = SnBr3 -(18)] containing M-SnX3 and P-Au-PPh3 functionalities. It was found that these reactions where the heteronuclear species are the precursors proceed via the trigonal-bipyramidal halides not only with X = Cl and Br(1a-4a) but also I(5a). When the precursors were 10a and 10b the reaction occurred with formation of [Pd(PNP)(PPh3)][SnCl 3]2 (23) and [Pt(PNP)(PPh3)][SnCl 2I]2 (24) showing M-PPh3 units and trihalostannato counter anions.
- Fernandez-Anca, Damian,Garcia-Seijo, M. Ines,Garcia-Fernandez, M. Esther
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- Catalyst-dependent selectivity in the relay catalytic branching cascade
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The synthesis of small organic molecules as probes for discovering new therapeutic agents has been an important aspect of chemical biology. One of the best ways to access collections of small molecules is to use various techniques in diversity-oriented synthesis (DOS). Recently, a new form of DOS, namely relay catalytic branching cascades (RCBCs), has been introduced, wherein a common type of starting material reacts with several scaffold-building agents (SBAs) to obtain structurally diverse molecular scaffolds under the influence of catalysts. Herein, the RCBC reaction of a common type of substrate with SBAs is reported to give two different types of molecular scaffolds and their formation is essentially dependent on the type of catalyst used.
- Bansode, Avinash H.,Shaikh, Aslam C.,Kavthe, Rahul D.,Thorat, Shridhar,Gonnade, Rajesh G.,Patil, Nitin T.
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- Bis(1,2,3-thiadiazole)s as precursors in the synthesis of bis(alkynethiolate)gold(I) derivatives
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The cleavage of bis(1,2,3-thiadiazole)s in the presence of strong bases in situ gives bis(alkynethiolate)s, which provide bis(alkynethiolate)gold(I) derivatives with the general formula [Au2(S-C≡C-spacer- C≡C-S)L2] (L = monophosphanes; spacer = none, 1,4-C 6H4, 1,3-C6H4, 2,7-C 15H12 and 3,5-C7H7N). The dinuclear structure was confirmed by X-ray diffraction studies of the complexes (PPN) 2[Au2(S-C≡C-C≡C-S)(C6F 5)2] and [Au2{3,5-(S-C≡C) 2-C7H7N}(PPh3)2] {PPN = bis(triphenylphosphane)iminium}. The use of diphosphanes gives complexes with higher nuclearity and cyclic structures. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
- Cerrada, Elena,Laguna, Mariano,Lardies, Nora
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- In vitro and in vivo studies of gold(I) azolate/phosphane complexes for the treatment of basal like breast cancer
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Basal like breast cancer (BLBC) is a very aggressive subtype of breast cancer giving few chances of survival, against which cisplatin based therapy is a compromise among the anticancer activity, the resistance development and the severe side effects. With the aim of finding new anticancer agents alternative to cisplatin, seven gold(I) azolate/phosphane compounds were evaluated in vitro by MTT tests in human MDA-MB-231, human mammary epithelial HMLE cells overexpressing FoxQ1, and murine A17 cells as models of BLBC. Two compounds, (4,5-dichloro-1H-imidazolate-1-yl)-(triphenylphosphane)-gold(I) 1 and (4,5-dicyano-1H-imidazolate-1-yl)-(triphenylphosphane)-gold(I) 2 were found very active and chosen for an in vivo study in A17 tumors transplanted in syngeneic mice. The compounds resulted to be more active than cisplatin, less nephrotoxic and generally more tolerated by the mice. This study also provides evidence that both gold(I) complexes inhibited the 19 S proteasome-associated deubiquitinase USP14 and induced apoptosis, while compound 1's mechanism of action depends also on its ability to down-regulate key molecules governing cancer growth and progression, such as STAT3 and Cox-2.
- Gambini, Valentina,Tilio, Martina,Maina, Eunice Wairimu,Andreani, Cristina,Bartolacci, Caterina,Wang, Junbiao,Iezzi, Manuela,Ferraro, Stefano,Ramadori, Anna Teresa,Simon, Oumarou Camille,Pucciarelli, Stefania,Wu, Guojun,Dou, Q. Ping,Marchini, Cristina,Galassi, Rossana,Amici, Augusto
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- Syntheses and structures of the heterometallic clusters [(Ph 3PAu)3Re(CO)4], [(Ph3PAu) 4Re(CO)4]+, [(Ph3PAu) 6AuRe2(CO)8]+, and [(Ph 3PAu)6Re(CO)3]+
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The reaction of [HRe3(CO)12]2- with an excess of Ph3PAuCl in CH2Cl2 yields [(Ph 3PAu)4Re(CO)4]+ as the main product, which crystallizes as [(Ph3PAu)4Re(CO) 4]PF6·CH2Cl2 (1·CH2Cl2) after the addition of KPF 6.The crystal structure determination reveals a trigonal bipyramidal Au4Re cluster with the Re atom in equatorial position. If [(Ph 3PAu)4Re(CO)4]+ is reacted with PPh4Cl, a cation [Ph3PAu]+ is eliminated as Ph3PAuCl, and the neutral cluster [(Ph3PAu) 3Re(CO)4] (2) is formed.It combines with excess [(Ph 3PAu)4Re(CO)4]+ to afford the cluster cation, [(Ph3PAu)6AuRe2(CO) 8]+. It crystallizes from CH2Cl2 as[(Ph3PAu)6AuRe2(CO)8]PF 6·4CH2Cl2 (3·4CH 2Cl2). In [(Ph3PAu)3Re(CO) 4] the metal atoms are arranged in form of a lozenge while in [(Ph3PAu)6AuRe2(CO)8]+ two Au4Re trigonal bipyramids are connected by a common axial Au atom. The treatment of [(Ph3PAu)4Re(CO)4] + with KOH and Ph3PAuCl in methanol yields the cluster cation [(Ph3PAu)6Re(CO)3]+, which crystallizes with PF6- from CH2Cl2 as [(Ph 3PAu)6Re(CO)3]PF6·CH 2Cl2 (4·CH2Cl2). The metal atoms in this cluster form a pentagonal bipyramid with the Re atom in the axial position.
- Pivoriunas,Richter,Str?hle
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- Ligand-stabilized Au13Cux (x = 2, 4, 8) bimetallic nanoclusters: Ligand engineering to control the exposure of metal sites
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Three novel bimetallic Au-Cu nanoclusters stabilized by a mixed layer of thiolate and phosphine ligands bearing pyridyl groups are synthesized and fully characterized by X-ray single crystal analysis and density functional theory computations. The three clusters have an icosahedral Au13 core face-capped by two, four, and eight Cu atoms, respectively. All face-capping Cu atoms in the clusters are triply coordinated by thiolate or pyridyl groups. The surface ligands control the exposure of Au sites in the clusters. In the case of the Au13Cu8 cluster, the presence of 12 2-pyridylthiolate ligands still leaves open space for catalysis. All the 3 clusters are 8-electron superatoms displaying optical gaps of 1.8-1.9 eV. The thermal decomposition studies suggest that the selective release of organic ligands from the clusters is possible.
- Yang, Huayan,Wang, Yu,Lei, Jing,Shi, Lei,Wu, Xiaohu,Maekinen, Ville,Lin, Shuichao,Tang, Zichao,He, Jian,Haekkinen, Hannu,Zheng, Lansun,Zheng, Nanfeng
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- Anti-fibrotic activity of gold and platinum complexes – Au(I) compounds as a new class of anti-fibrotic agents
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Molecular gold(I) and platinum(II) species were examined for the inhibition of liver fibrosis and the hepatitis C virus (HCV). Determination of inhibition efficiency was conducted via morphological analysis, cell viability, western blot analysis, and quantitative reverse transcription polymerase chain reaction (RT-PCR). Auranofin and Ph3PAuCl demonstrated the greatest inhibition of liver fibrosis amongst the tested gold species in human hepatic stellate LX-2 cells. Western blot analysis indicated that auranofin and Ph3PAuCl prevent signal transducer and activator of transcription 3 (STAT3) phosphorylation, which may be a key connection to fibrosis and inflammation. Auranofin and Ph3PAuCl also reduced expression of HCV-nonstructural protein 3 (NS3) and HCV-NS5a proteins in a HCV subgenomic replicon system. These results demonstrate significant promise for the use of gold compounds in treating liver diseases such as HCV.
- Camacho, Ehxciquiel Jaeroume M.,Grice, Kyle A.,Patil, Shivaputra,Ramachandran, Akshaya,Stratton, Matthew,Waris, Gulam
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- CHARACTERISTICS STRUCTURAL FEATURES OF CYCLOPENTADIENYL GERIVATIVES OF POST-TRANSITION METALS. II. SYNTHESIS AND STRUCTURE OF TRIS(TRIPHENYLPHOSPHINEGOLD)TETRAPHENYLCYCLOPENTADIENE TETRAFLUOROBORATE
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The trinuclear cationic complex +- (I) obtained by interaction of C5HPh4AuPPh3 or Ph4C5(AuPPh3)2 with +- in THF was studied by X-ray diffraction.In the presence of benzene, triclinic crystals of the solvate +- * 2C6H6 are formed, a=12.845(6), b=16.042(8), c=22.642(11) Angstroem, α=86.62(4), β=77.51(4), γ=76.05(4) deg, space group P, Z=2, 9494 reflections with I > 2? (λ(Mo-Kα), θ/2θ scan, 2θ 46 deg), with absorption correction R=0.054.The complex represents a diaurated cation of tetraphenylcyclopentadienyl(triphenylphosphine)gold, containing a triangular Au2C fragment (Au-Au 2.820(1) Angstroem) which is bonded to the third Au atom (Au-Au 3.021(1) Angstroem), coordinated to the cyclopentadienyl ligand by a bond intermediate between η1(?) and η3 (Au-C 2.21(2), 2.60(2) and 2.71(2) Angstroem).
- Baukova, T. V.,Slovokhotov, Yu. L.,Struchkov, Yu. T.
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- Synthesis of phenyl>(2-nitrophenyl)gold(III) complexes
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reacts with and (Me4N)Cl (2/1/2) to give (I).Metathetical reactions of I with AgAc (Ac = OOCCH3), KBr or KI give complexes (X = Ac (II), Br (III), I (IV), all of which are obtained as mixtures of two isomers.The reaction of I with PPh3 (1/1) gives (V), which reacts with NaClO4 (1/1) to give ClO4 (VI).This can also be obtained directly by treating I with PPh3 and NaClO4 (1/1/1).A similar method (I + L + AgClO4) can be used to prepare ClO4 (py = pyridine) (VII).
- Vicente, Jose,Bermudez, Maria-Dolores,Chicote, Maria-Teresa,Sanchez-Santano, Maria-Jose
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- Enhanced magneto-optical properties of semiconductor EuS nanocrystals assisted by surface plasmon resonance of gold nanoparticles
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Remarkable magneto-optical properties of a new isolator material, that is, europium sulfide nanocrystals with gold (EuS-Au nanosystem), has been demonstrated for a future photo-information technology. Attachment of gold particles that exhibit surface plasmon resonance leads to amplification of the magneto-optical properties of the EuS nanocrystals. To construct the EuS-Au nanosystems, cubic EuS and spherical Au nanocrystals have been joined by a variety of organic linkers, that is, 1,2-ethanedithiol (EDT), 1,6-hexanedithiol (HDT), 1,10-decanedithiol (DDT), 1,4-bisethanethionaphthalene (NpEDT), or 1,4-bisdecanethionaphthalene (NpDDT). Formation of these systems was observed by XRD, TEM, and absorption spectra measurements. The magneto-optical properties of the EuS-Au nanosystem have been characterized by using Faraday rotation spectroscopy. The Faraday rotation angle of the EuS-Au nanosystem is dependent on the Au particle size and interparticle distance between EuS and Au nanocrystals. Enhancement of the Faraday rotation of EuS-Au nanosystems was observed. The spin configuration in the excited state of the EuS-Au nanosystem was also investigated using photo-assisted electron paramagnetic resonance. Copyright
- Kawashima, Akira,Nakanishi, Takayuki,Shibayama, Tamaki,Watanabe, Seiichi,Fujita, Koji,Tanaka, Katsuhisa,Koizumi, Hitoshi,Fushimi, Koji,Hasegawa, Yasuchika
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- Monomeric Chini-Type Triplatinum Clusters Featuring Dianionic and Radical-Anionic π*-Systems
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Owing to their unique topologies and abilities to self-assemble into a variety of extended and aggregated structures, the binary platinum carbonyl clusters [Pt3(CO)6]n2?(“Chini clusters”) continue to draw significant interest. Herein, we report the isolation and structural characterization of the trinuclear electron-transfer series [Pt3(μ-CO)3(CNArDipp2)3]n?(n=0, 1, 2), which represents a unique set of monomeric Pt3clusters supported by π-acidic ligands. Spectroscopic, computational, and synthetic investigations demonstrate that the highest-occupied molecular orbitals of the mono- and dianionic clusters consist of a combined π*-framework of the CO and CNArDipp2ligands, with negligible Pt character. Accordingly, this study provides precedent for an ensemble of carbonyl and isocyanide ligands to function in a redox non-innocent manner.
- Barnett, Brandon R.,Rheingold, Arnold L.,Figueroa, Joshua S.
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- PPh3AuTFA Catalyzed in the Dearomatization of 2-Naphthols with Allenamides
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A new catalytic methodology for the direct dearomatization of substituted 2-naphthols via intermolecular condensation with allenamides is presented. PPh3AuTFA (5 mol?%) promotes the formal allylating dearomative protocol under mild conditions, large scope (24 examples), and high regioselectivity and stereoselectivity. The synergistic catalytic role played by the [PPh3Au]+ (π-acid) and TFA- (Lewis base) is highlighted.
- An, Juzeng,Lombardi, Lorenzo,Grilli, Stefano,Bandini, Marco
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- Synthesis of a fluorescent gold(I) complex with a thiosemicarbazone, [Au2(3-NO2-Hbtsc)4]Cl2 · 2CH3CN
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Direct reaction of gold(I) chloride with 3-nitrobenzaldehyde thiosemicarbazone (3-NO2-Hbtsc) in the presence of triphenylphosphine in acetonitrile has yielded ionic complex, [Au2(3-NO2-Hbtsc)4]Cl2 · 2CH3CN (1). It exhibited an intense fluorescence band (λem) at 383 nm (λex = 300 nm), and two bands of medium intensity at 413 and 436 nm (λex = 350 nm). Complex 1 represents first example of ionic gold(I) complex with a thiosemicarbazone.
- Lobana, Tarlok S.,Khanna, Sonia,Butcher, Ray J.
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- Dinuclear Au(I), Au(II) and Au(III) Complexes with (CF2)n Chains: Insights into The Role of Aurophilic Interactions in the Au(I) Oxidation
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New dinuclear Au(I), Au(II) and Au(III) complexes containing (CF2)n bridging chains were obtained. Metallomacrocycles [Au2{μ-(CF2)4}{μ-diphosphine}] show an uncommon figure-eight structure, the helicity inversion barrier of which is influenced by aurophilic interactions and steric constraints imposed by the diphosphine. Halogenation of LAu(CF2)4AuL (L=PPh3, PMe3, (dppf)1/2, (binap)1/2) gave [Au(II)]2 species, some of which display unprecedented folded structures with Au?Au bonds. Aurophilic interactions facilitate this oxidation process by preorganizing the starting [Au(I)]2 complexes and lowering its redox potential. The obtained [Au(II)]2 complexes undergo thermal or photochemical elimination of R3PAuX to give Au(III) perfluorinated auracycles. Evidence of a radical mechanism for these decomposition reactions was obtained.
- Portugués, Alejandro,Bautista, Delia,Gil-Rubio, Juan
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- Cationic gold catalyst poisoning and reactivation
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High gold affinity impurities (halides, bases) in solvents, starting materials, filtration, or drying agents could affect the reactivity of gold catalyst adversely, which may significantly reduce the TON of cationic gold-catalyzed reactions. Use of a suit
- Kumar, Manish,Hammond, Gerald B.,Xu, Bo
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- Mixed gold(I)-gold(III) complexes with bridging selenido ligands. Theoretical studies of the gold(I)-gold(III) interactions
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The gold(I) compounds [Se(AuPPh3)2] and [Se{Au2(μ-dppf)}] (dppf = 1,1′-bis(diphenylphosphino)ferrocene) react with 1 and 2 equiv of [Au(C6F5)3OEt2] to give the mixed gold(I)-gold(III) derivatives [Se(AuPPh3)2{Au(C6 F5)3}n] and [Se{Au2(μ-dppf)}{Au(C6 F5)3}n] (n = 1, 2). The reaction of [Se(AuPPh3)2] with [Au(C6F5)2Cl]2 affords the complex [{Se(AuPPh3)}2{μ-Au-(C6 F5)2}2]. The crystal structures of [Se{Au2(μ-dppf)}{Au(C6F5)3}] and [{Se(AuPPh3)}2{μ-Au-(C6 F5)2}2] have been characterized by X-ray diffraction studies. They show dissimilar Au(I)??Au(III) distances, indicating the presence of weak interactions. Quasi-relativistic pseudopotential calculations on [Se(AuPH3)2(AuR3)], [Se(AuPH3) (AuR3)2]- (R = -H, -CH3), and [{Se(AuPH3)}2 {Au(CH3)2}2] models have been performed at Hartree-Fock and second-order M?ller-Plesset perturbation theory levels. There is a good agreement between experimental and theoretical geometries at the MP2 level.
- Canales, Silvia,Crespo, Olga,Gimeno, M. Concepcion,Jones, Peter G.,Laguna, Antonio,Mendizabal, Fernando
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- The photochemistry of chloro(triphenylphosphine)gold(I) and trichloro(triphenylphosphine)gold(III) in chloroform
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AuCl(PPh3) in chloroform under 254 nm irradiation is converted to AuCl3(PPh3), which is itself converted photochemically to HAuCl4. The absorption of light by both AuCl(PPh3) and the solvent lead to o
- Serafimova, Iana M.,Hoggard, Patrick E.
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- Silver(I) and gold(I) complexes with sulfasalazine: Spectroscopic characterization, theoretical studies and antiproliferative activities over Gram-positive and Gram-negative bacterial strains
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The emergence of bacterial strains resistant to antibiotics, such as the sulfonamides (sulfa drugs), is currently a case of concern. The synthesis of metal complexes using well-known antibacterial agents and bioactive metals has proven to be an excellent strategy in the development of new and more active metallodrugs. Herein, we report the synthesis, structural characterization and antibacterial analysis of new gold(I) and silver(I) complexes with the sulfa drug sulfasalazine (ssz). Elemental, thermal and high-resolution mass spectrometric measurements indicated a 1:1:1 Au/ssz/Ph3P molar composition for the gold(I) complex (Ph3P - triphenylphosphine), while for the silver(I) complex the molar composition was 1:1 Ag/ssz. Solution state NMR and infrared spectroscopic data suggest that ssz coordinates to silver(I) and gold(I) by the oxygen atoms of the deprotonated carboxylic group. The coordination mode of the carboxylate was supported by density functional theory (DFT) calculations, which reinforces a monodentate coordination for the gold(I) complex and a bridged bidentate mode for the silver(I) one, with the molecular formulas [(Ph3P)Au(ssz)] and [Ag(ssz)]2, respectively. Antibacterial activity assays indicated the sensitivity of Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains to [Ag(ssz)]2 and [(Ph3P)Au(ssz)] complexes, while the free ligand was not able to inhibit the growth of any tested bacteria. The non-interaction of the complexes with deoxyribonucleic acid (DNA) was also demonstrated, which suggests that this biomolecule is not a preferential target for the compounds.
- Corbi, Pedro P.,Fiori-Duarte, Ana Thereza,Lustri, Wilton R.,Manzano, Carlos M.,de Paiva, Raphael Enoque F.
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- Covalently Binding Atomically Designed Au9 Clusters to Chemically Modified Graphene
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Atomic-resolution transmission electron microscopy was used to identify individual Au9 clusters on a sulfur-functionalized graphene surface. The clusters were preformed in solution and covalently attached to the surface without any dispersion or aggregation. Comparison of the experimental images with simulations allowed the rotational motion, without lateral displacement, of individual clusters to be discerned, thereby demonstrating a robust covalent attachment of intact clusters to the graphene surface.
- Bosch-Navarro, Concha,Laker, Zachary P. L.,Thomas, Helen R.,Marsden, Alexander J.,Sloan, Jeremy,Wilson, Neil R.,Rourke, Jonathan P.
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- Hydride, chloride, and bromide show similar electronic effects in the Au9(PPh3)83+ nanocluster
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Recent experimental and computational results have suggested that a hydride bound to the Au9(PPh3)83+ gold nanocluster donates its electrons to the metal core, forming an 8-electron cluster. We present electronic absorption spectra of precisely mass-selected Au9(PPh3)83+ clusters featuring a surface hydride, chloride, or bromide. Comparison of these spectra shows that H-, Cl-, or Br- perturb the electronic structure of the Au9(PPh3)83+ core in similar ways. This suggests that hydride and halides play similar roles electronically in this cluster, and thus are either both metallic or both ligand-like.
- Cirri, Anthony,Hernández, Hanna Morales,Johnson, Christopher J.
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supporting information
p. 1283 - 1285
(2020/02/04)
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- GOLD COMPOSITIONS AND METHODS OF USE THEREOF
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Gold compounds and pharmaceutically acceptable salts thereof are disclosed. Certain compounds and salts are active as antibacterial, antifungal, and/or anti-parasitic agents. The disclosure provides pharmaceutical compositions containing the gold compounds. Methods of using the gold compounds to treat bacterial infections are disclosed.
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Paragraph 0075; 0117; 0118; 0120; 0122
(2020/03/05)
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- Visible-Light-Assisted Gold-Catalyzed Fluoroarylation of Allenoates
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A strategically novel synthetic method for the fluoroarylation of allenic ester was developed that enables the expedient construction of a host of β-fluoroalkyl-containing cinnamate derivatives. The reaction proceeds through visible-light-promoted gold redox catalysis, occurs smoothly under very mild reaction conditions, accommodates a large variety of functional groups, and more importantly allows the incorporation of fluorine and aryl groups with excellent regio- and stereoselectivity. The concomitant activation mode for both the allene motif and the hydrogen fluoride is key for the success of the reaction.
- Feng, Chao,Tang, Hai-Jun,Zhang, Xinggui,Zhang, Yu-Feng
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supporting information
p. 5242 - 5247
(2020/02/28)
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- Synthesis and Structure-Activity Relationship Study of Antimicrobial Auranofin against ESKAPE Pathogens
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Auranofin, an FDA-approved arthritis drug, has recently been repurposed as a potential antimicrobial agent; it performed well against many Gram-positive bacteria, including multidrug resistant strains. It is, however, inactive toward Gram-negative bacteria, for which we are in dire need of new therapies. In this work, 40 auranofin analogues were synthesized by varying the structures of the thiol and phosphine ligands, and their activities were tested against ESKAPE pathogens. The study identified compounds that exhibited bacterial inhibition (MIC) and killing (MBC) activities up to 65 folds higher than that of auranofin, making them effective against Gram-negative pathogens. Both thiol and the phosphine structures influence the activities of the analogues. The trimethylphosphine and triethylphosphine ligands gave the highest activities against Gram-negative and Gram-positive bacteria, respectively. Our SAR study revealed that the thiol ligand is also very important, the structure of which can modulate the activities of the AuI complexes for both Gram-negative and Gram-positive bacteria. Moreover, these analogues had mammalian cell toxicities either similar to or lower than that of auranofin.
- Wu, Bin,Yang, Xiaojian,Yan, Mingdi
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p. 7751 - 7768
(2019/09/10)
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- Oxidant speciation and anionic ligand effects in the gold-catalyzed oxidative coupling of arenes and alkynes
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The mechanism of the gold-catalyzed oxidative cross-coupling of arenes and alkynes has been studied in detail combining stoichiometric experiments with putative reaction intermediates and DFT calculations. Our data suggest that ligand exchange between the alkyne, the Au(i)-catalyst and the hypervalent iodine reagent is responsible for the formation of both an Au(i)-acetylide complex and a more reactive "non-symmetric" I(iii) oxidant responsible for the crucial Au(i)/Au(iii) turnover. Further, the reactivity of the in situ generated Au(iii)-acetylide complex is governed by the nature of the anionic ligands transferred by the I(iii) oxidant: while halogen ligands remain unreactive, acetato ligands are efficiently displaced by the arene to yield the observed Csp2-Csp cross-coupling products through an irreversible reductive elimination step. Finally, the nature of competitive processes and catalyst deactivation pathways has also been unraveled. This detailed investigation provides insights not only on the specific features of the species involved in oxidative gold-catalyzed cross couplings but also highlights the importance of both ancillary and anionic ligands in the reactivity of the key Au(iii) intermediates.
- Hofer, Manuel,De Haro, Teresa,Gómez-Bengoa, Enrique,Genoux, Alexandre,Nevado, Cristina
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p. 8411 - 8420
(2019/09/30)
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- Systematically Tuning the Electronic Structure of Gold Nanoclusters through Ligand Derivatization
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While the ability to crystallize metal nanoclusters has revealed their geometric structure, the lack of a similarly precise measure of their electronic structure has hampered the development of synthetic design rules to precisely engineer their electronic properties. We track the evolution of highly-resolved electronic absorption spectra of gold nanoclusters with precisely mass-selected chemical composition in a controlled environment. Simple derivatization of the ligands yields larger spectral changes than varying the overall atomic composition of the cluster for two clusters with similar symmetry and size. The nominally metal-localized HOMO–LUMO transition of these nanoclusters lowers in energy linearly with increasing electron donation from the exterior of the ligand shell for both cluster sizes. Very weak surface interactions, such as binding of He or N2, yield significant state-dependent shifts, identifying states with significant interfacial character. These observations demonstrate a pathway for deliberate tuning of interfacial chemistry for chemical and technological applications.
- Cirri, Anthony,Morales Hernández, Hanna,Kmiotek, Christina,Johnson, Christopher J.
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supporting information
p. 13818 - 13822
(2019/08/22)
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- New transmetalation reagents for the gold-catalyzed visible light-enabled C(sp or sp2)-C(sp2) cross-coupling with aryldiazonium salts in the absence of a photosensitizer
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The scope of photosensitizer-free visible light-driven gold-catalyzed cross-coupling was evaluated by a wide variety of organoboron and organosilicon species using four equivalents of aryldiazonium salts and (4-CF3-C6H4)3PAuCl in MeOH. In addition, a C(sp or sp2)-C(sp2) cross-coupling of organotrimethylsilanes and aryldiazonium salts was investigated. The reactions can be conducted under very mild reaction conditions, with a reduced amount of aryldiazonium salt (1.2 equiv.) by using a catalytic amount of Ph3PAuNTf2 in MeCN under irradiation with blue LEDs at room temperature.
- Witzel, Sina,Sekine, Kohei,Rudolph, Matthias,Hashmi, A. Stephen K.
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supporting information
p. 13802 - 13804
(2018/12/14)
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- Oxidative Mechanochemistry: Direct, Room-Temperature, Solvent-Free Conversion of Palladium and Gold Metals into Soluble Salts and Coordination Complexes
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Noble metals are valued, critical elements whose chemical activation or recycling is challenging, and traditionally requires high temperatures, strong acids or bases, or aggressive complexation agents. By using elementary palladium and gold, demonstrated here is the use of mechanochemistry for noble-metal activation and recycling by mild, clean, solvent-free, and room-temperature chemistry. The process leads to direct, efficient, one-pot conversion of the metals, including spent catalysts, into either simple water-soluble salts or metal–organic catalysts.
- Do, Jean-Louis,Tan, Davin,Fri??i?, Tomislav
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supporting information
p. 2667 - 2671
(2018/02/06)
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- The facile approach to fabricate gold nanoparticles and their application on the hydration and dehydrogenation reactions
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A mild and practical strategy to prepare gold nanoparticles was developed. This gold particles supported mesoporous silica was fabricated from AuPPh3Cl under mild conditions and characterized through transmission electron microscopy, energy dispersive X-ray, X-ray power diffraction and X-ray photoelectron spectrometry. Interestingly, it was observed that this gold nanoparticle was effective to the hydration of alkynes and dehydrogenation of alcohols. The catalytic system can tolerate a variety of functional groups to afford the corresponding products in good to excellent yields.
- Huang, Ronghui,Fu, Yong,Zeng, Wei,Zhang, Liang,Wang, Dawei
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- Reversible Covalent and Supramolecular Functionalization of Water-Soluble Gold(I) Complexes
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The ligation of gold(I) metalloamphiphiles with biomolecules is reported, using water-soluble AuI-N-alkynyl substituted maleimide complexes. For this purpose, two different polar ligands were applied: 1) a neutral, dendritic tetraethylene glycol-functionalized phosphane and 2) a charged, sulfonated N-heterocyclic carbene (NHC). The retro Diels–Alder reaction of a furan-protected maleimide gold(I) complex, followed by cycloaddition with a diene-functionalized biotin under mild conditions leads to a novel gold(I) metalloamphiphile. The strong streptavidin–biotin binding affinity in buffered aqueous solution of the resulting biotin alkynyl gold(I) phosphane conjugate remains intact. The cytotoxicity of the biotinylated gold(I) complex against a T47D human breast cancer cell line is higher than for cisplatin.
- Kemper, Benedict,von Gr?ning, Maximilian,Lewe, Vanessa,Spitzer, Daniel,Otremba, Tobias,Stergiou, Natascha,Schollmeyer, Dieter,Schmitt, Edgar,Ravoo, Bart Jan,Besenius, Pol
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supporting information
p. 6048 - 6055
(2017/05/08)
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- Janus-Type Bis(maloNHC) and Its Zwitterionic Gold and Silver Metal Complexes
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A new Janus-type dianionic bis(maloNHC) (1) was synthesized and characterized by NMR spectroscopy. The utility of this extended biscarbene for the construction of homobimetallic systems has been demonstrated by its coordination to two coinage metals. The resulting zwitterionic metal complexes of the type [(Ph3P)M(1)M(PPh3)] (M = Au, Ag) have been fully characterized. The X-ray crystallography shows that the new ligand positions the two metal centers at a distance of 24.2 ?, the longest distance reported to date for any related NHC ligand.
- Carter, Ashley,Mason, Alexander,Baker, Michael A.,Bettler, Donald G.,Changas, Angelo,McMillen, Colin D.,Tapu, Daniela
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p. 1867 - 1872
(2017/05/15)
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- Gold-Catalyzed Access to 1H-Isochromenes: Reaction Development and Mechanistic Insight
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The gold-catalyzed domino cyclization/nucleophilic reaction of ortho-carbonylalkynylaryls has been studied. Thus, 2-(pyridin-2-ylethynyl)benzaldehyde has been chosen to isolate key intermediates that may take part in the reaction mechanism. Employing Hantzsch ester (HEH) as nucleophile, it has been impossible to isolate the corresponding gold-alkenyl specie; however, when methanol was used as solvent (and nucleophile), the expected chelate gold-vinyl complex was isolated and unambiguously characterized by X-ray analysis. When HEH is present in the alcoholic reaction mixture, isotopic studies show that the cleavage of the Au-C bond of gold-vinyl complex proceeds through a protodemetalation pathway, rather than a plausible metal-hydride reductive elimination mechanism. Finally, with the aim of broadening the scope of the cyclization/reduction reaction previously reported, we present that the catalytic system is robust and applicable for a diverse family of challenging substrates presenting ester, aldehyde, ether, alkene, and alkyne functionalities.
- Tomás-Mendivil, Eder,Heinrich, Clément F.,Ortuno, Jean-Claude,Starck, Jér?me,Michelet, Véronique
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p. 380 - 387
(2017/06/07)
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- An efficient approach to chloro(organophosphine) gold(i) complexes for the synthesis of auranofin
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A practical and efficient synthesis of chloro(organophosphine) gold(i) complexes is reported. Employment of 4,4′-dihydroxydiphenyl sulfide as a safe and non-irritating reductant is highlighted for the generation of Au(i)-S intermediates, which could be trapped by mono- and bidentate phosphine ligands to provide organophosphine gold(i) complexes. The utility of the present method is further demonstrated by the synthesis of the antiarthritic drug auranofin.
- Wang, Junchang,Mi, Xuemeng,Wang, Jiazhe,Yang, You
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supporting information
p. 634 - 637
(2017/08/15)
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- Oxidative 1,2-Difunctionalization of Ethylene via Gold-Catalyzed Oxyarylation
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Under the conditions of oxidative gold catalysis, exposure of ethylene to aryl silanes and alcohols generates products of 1,2-oxyarylation. This provides a rare example of a process that allows catalytic differential 1,2-difunctionalization of this feedstock chemical.
- Harper, Matthew J.,Emmett, Edward J.,Bower, John F.,Russell, Christopher A.
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supporting information
p. 12386 - 12389
(2017/09/22)
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- Photosensitizer-Free, Gold-Catalyzed C–C Cross-Coupling of Boronic Acids and Diazonium Salts Enabled by Visible Light
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The first photosensitizer-free visible light-driven, gold-catalyzed C–C cross-couplings of arylboronic acids and aryldiazonium salts are reported. The reactions can be conducted under very mild conditions, using a catalytic amount of tris(4-trifluoromethyl)phosphinegold(I) chloride [(4-CF3-C6H4)3PAuCl] with methanol as the solvent allowing an alternative access to a variety of substituted biaryls in moderate to excellent yields with broad functional group tolerance. (Figure presented.).
- Witzel, Sina,Xie, Jin,Rudolph, Matthias,Hashmi, A. Stephen K.
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supporting information
p. 1522 - 1528
(2017/05/05)
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- Gold(I)-Catalyzed Cascade: Synthesis of 2,5-Disubstituted Pyrroles from N -Sulfonyl-2-(1-ethoxypropargyl)azetidines through Cyclization/Nucleophilic Substitution/Elimination
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N -Sulfonyl-2-(1-ethoxypropargyl)azetidine derivatives undergo a gold-catalyzed rearrangement in the presence of various alcohols furnishing the 2,5-disubstituted pyrroles in excellent yields (11 examples, 63-86%). Iodide or deuterium trappings of organogold intermediate as well as kinetic study confirmed the postulated cyclization/nucleophilic substitution/elimination mechanism..
- Pertschi, Romain,Miaskiewicz, Solène,Weibel, Jean-Marc,Pale, Patrick,Blanc, Aurélien
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p. 4151 - 4162
(2017/09/12)
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- A substituted bay position gold[...] imide derivatives (by machine translation)
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A substituted bay position gold[...] imide derivatives, its chemical formula is R 2-PDI-R 1, the structural formula , In the formula: derivatives in PDI-a R 1 to PPh 3, R 2 to H; derivative compound in PDI-b R 1 to PPh 3, R 2 to Au-PPh 3; in PDI-b the derivation gathers the thing R1 to C ≡ N-Ph, R 2 to H. Substituted position goldstates the bay[...] the preparation process of imide derivative, the steps are as follows : (1) synthesis of diamide derivatives perylen ; (2) synthesis of gold-containing derivatives. The advantage of this invention is: the method of preparing substituted bay position gold[...] imide derivatives, fluorescent obviously enhance and stable properties, good heat conducting properties, in aviation and aerospace, photoelectric. Many machinery and the like, and have a wide range of application prospect. (by machine translation)
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Paragraph 0030; 0054
(2017/02/09)
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- Method for preparing organic phosphonic gold chloride (I) compound
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The invention discloses a method for preparing an organic phosphonic gold chloride (I) compound. The method comprises the following steps: (1) adding chloroauric acid hydrated salt into a reaction container, dissolving with water, and uniformly stirring in an ice-water bath; (2) keeping the temperature of the ice water in the reaction container, dripping a glucosinolates diaryl compound or a derivative of the glucosinolates diaryl compound, and stirring uniformly; (3) dripping a mixed liquid of phosphine-containing ligand and ethanol into the reaction container one droplet by one droplet, removing the ice-water bath, recovering the room temperature naturally, and stirring for 2-5 hours; (4) stopping stirring, performing suction filtration, washing with cold methanol, dissolving the collected solid with an organic solvent, and performing suction filtration again so as to remove insoluble matters; (5) performing concentration spinning drying on the solution, recrystallizing with a solvent, and performing suction filtration again, thereby obtaining the organic phosphonic gold chloride (I) compound. As the glucosinolates diaryl compound or the derivative of the glucosinolates diaryl compound is taken as a reduction reagent, and due to reaction between the chloroauric acid hydrated salt and the phosphine-containing ligand in an ethanol-water system, environment-friendly, safe and efficient production of the organic phosphonic gold chloride (I) compound can be achieved, and moreover, industrial application of the organic phosphonic gold chloride (I) compound is facilitated.
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Paragraph 0037; 0038; 0039; 0040; 0041; 0042
(2016/12/16)
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- Gold-Catalyzed Anti-Markovnikov Selective Hydrothiolation of Unactivated Alkenes
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Despite the widespread use of transition-metal catalysts in organic synthesis, transition-metal-catalyzed reactions of organosulfur compounds, which are known as catalyst poisons, have been difficult. In particular, the transition-metal-catalyzed addition of organosulfur compounds to unactivated alkenes remains a challenge. A novel gold-catalyzed hydrothiolation of unactivated alkenes is presented, which proceeds effectively to give the anti-Markovnikov-selective adducts in good yields and in a regioselective manner.
- Tamai, Taichi,Fujiwara, Keiko,Higashimae, Shinya,Nomoto, Akihiro,Ogawa, Akiya
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supporting information
p. 2114 - 2117
(2016/06/01)
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- Synthesis of Substituted Quinolizidines via a Gold-Catalyzed Double Cyclization Cascade
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A novel synthesis of quinolizidines by a cationic gold-catalyzed double cyclization cascade has been developed. The reaction was initiated by the gold-catalyzed 6-exo-dig cyclization of ynamides, which was followed by a second cyclization of an enamide intermediate to provide the corresponding quinolizidine derivatives. The utility of this reaction was demonstrated by application to the synthesis of multi-substituted quinolizidines and by the total synthesis of a quinolizidine alkaloid, (±)-lupinine.
- Nonaka, Shiori,Sugimoto, Kenji,Ueda, Hirofumi,Tokuyama, Hidetoshi
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supporting information
p. 380 - 385
(2016/02/12)
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- Facile Gold-Catalyzed Heterocyclization of Terminal Alkynes and Cyanamides Leading to Substituted 2-Amino-1,3-Oxazoles
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Facile gold-catalyzed heterocyclization based upon intermolecular trapping of the generated α-oxo gold carbenes with various cyanamides R2R3NCN (R2/R3 = Alk/Alk, -(CH2)2O(CH2)2-, Ar/Ar, Ar/H) has been developed. In most cases, 2-amino-1,3-oxazoles functionalized at the nitrogen atom as well as at the fifth position of the heterocyclic ring (12 examples) were isolated in good to moderate yields.
- Rassadin, Valentin A.,Boyarskiy, Vadim P.,Kukushkin
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supporting information
p. 3502 - 3505
(2015/07/28)
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- Revisiting the Influence of Silver in Cationic Gold Catalysis: A Practical Guide
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An excess amount of silver salt to generate cationic gold from a gold catalyst precursor such as L-Au-Cl almost always has adverse effects on the reactivity of the cationic gold catalyst. A preformed L-Au+X- complex, generated by sonication followed by centrifugation, increases the reactivity in a gold catalyzed reaction. The adverse silver effect might be caused by the interaction of silver salts with gold intermediates.
- Lu, Zhichao,Han, Junbin,Hammond, Gerald B.,Xu, Bo
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supporting information
p. 4534 - 4537
(2015/09/28)
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- Formal Gold-to-Gold Transmetalation of an Alkynyl Group Mediated by Palladium: A Bisalkynyl Gold Complex as a Ligand to Palladium
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The reaction of [Au(C-C n-Bu)]n with [Pd(η3-allyl)Cl(PPh3)] results in a ligand and alkynyl rearrangement, and leads to the heterometallic complex [Pd(η3-allyl){Au(C-C n-Bu)2}]2 (3) with an unprecedented bridging bisalkynyl-gold ligand coordinated to palladium. This is a formal gold-to-gold transmetalation that occurs through reversible alkynyl transmetalations between gold and palladium. Back and forth! Direct gold-to-palladium and reverse palladium-to-gold alkynyl transmetalations effectively produce a deceptively simple gold-to-gold transfer. The resulting bisalkynyl-gold complexes act as bridging ligands to palladium atoms in an unprecedented structural motive (see scheme).
- Toledo, Alberto,Meana, Isabel,Albéniz, Ana C.
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supporting information
p. 13216 - 13220
(2015/09/15)
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- Reversible control of nanoparticle functionalization and physicochemical properties by dynamic covalent exchange
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Existing methods for the covalent functionalization of nanoparticles rely on kinetically controlled reactions, and largely lack the sophistication of the preeminent oligonucleotide-based noncovalent strategies. Here we report the application of dynamic covalent chemistry for the reversible modification of nanoparticle (NP) surface functionality, combining the benefits of non-biomolecular covalent chemistry with the favorable features of equilibrium processes. A homogeneous monolayer of nanoparticle-bound hydrazones can undergo quantitative dynamic covalent exchange. The pseudomolecular nature of the NP system allows for the in situ characterization of surface-bound species, and real-time tracking of the exchange reactions. Furthermore, dynamic covalent exchange offers a simple approach for reversibly switching - and subtly tuning - NP properties such as solvophilicity.
- Della Sala, Flavio,Kay, Euan R.
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supporting information
p. 4187 - 4191
(2015/03/31)
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- Sequential O-H/C-H bond insertion of phenols initiated by the gold(I)-catalyzed cyclization of 1-bromo-1,5-enynes
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The development of a sequential O-H/C-H bond functionalization of phenols initiated by the cationic gold(I)-catalyzed cyclization of 1-bromo-1,5-enynes to produce (2-bromocyclopent-2-en-1-yl)phenols is reported. This unprecedented domino transformation efficiently proceeds under mild conditions (5 mol % of (t-Bu)3PAuNTf2, CH2Cl2, 0-23 °C) via an intermediate aryl alkyl ether which collapses at ambient temperature to undergo a 1,2-hydride shift followed by C-H insertion of the phenol.
- Speck, Klaus,Karaghiosoff, Konstantin,Magauer, Thomas
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supporting information
p. 1982 - 1985
(2015/04/27)
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- The importance of Au ... π(aryl) interactions in the formation of spherical aggregates in binuclear phosphane gold(I) complexes of a bipodal thiocarbamate dianion: A combined crystallographic and computational study, and anti-microbial activity
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Binuclear phosphanegold(i) complexes of a bipodal thiocarbamate dianion, (R3PAu)2L, R = Et (1), Ph (2) and Cy (3), where LH2 is {1,4-[MeOC(S)N(H)]2C6H4}, have been synthesised, and characterised spectroscopically (NMR and IR) and by X-ray crystallography. The gold atoms are linearly coordinated within a P-,S-donor set, and are oriented toward the central ring to form intramolecular Au ...π(aryl) interactions, rather than the intramolecular Au ...O interactions normally observed in mononuclear analogues. This phenomenon has been investigated by theory (LC-ωPBE-XDM) for 1 which revealed that the geometry optimised species with two Au ...π(aryl) interactions is more stable by at least 12 kcal mol-1 compared to conformations having one or more Au ...O interactions instead. The disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods were used to observe the inhibitory effect of complexes 1-3. The disk diffusion results demonstrated that 1 exhibited a broad spectrum of anti-bacterial activity toward 24 strains of Gram-positive and Gram-negative bacteria. By contrast, the anti-bacterial activity of 2 and 3 was limited to Gram-positive bacteria. Further evaluation showed that 1 exhibited marked bactericidal activity against B. cereus, B. subtilis, E. faecalis, L. monocytogenes, S. aureus, S. saprophyticus and methicillin resistant S. aureus cf. standard antibiotics tetracycline and chloramphenicol.
- Yeo, Chien Ing,Khoo, Chai-Hoon,Chu, Wern-Cui,Chen, Bao-Jing,Chu, Pek-Lim,Sim, Jiun-Horng,Cheah, Yoke-Kqueen,Ahmad, Jimmy,Abdul Halim, Siti Nadiah,Seng, Hoi-Ling,Ng, Soon,Otero-De-La-Roza,Tiekink, Edward R. T.
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p. 41401 - 41411
(2015/05/27)
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- Potassium tris(triflyl)methide (KCTf3): A broadly applicable promoter for cationic metal catalysis
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KCTf3, a commercially available, easily handled neutral salt, enhanced the reaction rates and the chemical yields of a wide spectrum of cationic metal catalyzed reactions, ranging from traditional Lewis acid catalysis to transition metal catalysis.
- Han, Junbin,Lu, Zhichao,Wang, Weibo,Hammond, Gerald B.,Xu, Bo
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supporting information
p. 13740 - 13743
(2015/09/07)
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- Solvent effects in gold-catalysed A3-coupling reactions
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Gold-catalysed A3-reactions proceed efficiently when conducted in 2,2,2-trifluoroethanol as solvent. The rates of these reactions are accelerated considerably when conducted in a microwave reactor.
- Price, Gregory A.,Brisdon, Alan K.,Flower, Kevin R.,Pritchard, Robin G.,Quayle, Peter
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supporting information
p. 151 - 154
(2014/01/06)
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- Gold catalysis: Biarylphosphine ligands as key for the synthesis of dihydroisocoumarins
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Agold-catalyzed phenol synthesis was successfully used in the synthesis of dihydroisocoumarins for the first time.Alarge number of gold(I) complexes were prepared and tested; only complexes based on the biarylphosphine motif were successful. CSIRO 2014.
- Hashmi, A. Stephen K.,Bechem, Benjamin,Loos, Annette,Hamzic, Melissa,Rominger, Frank,Rabaa, Hassan
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p. 481 - 499
(2014/04/03)
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- The gilded edge in acetylenic scaffolding: Pd-catalyzed cross-coupling reactions of phosphine-gold(I) oligoynyl complexes
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Stable bis(gold(I) alkynyl) complexes of tetraethynylethene (TEE) derivatives were readily prepared and employed in Sonogashira-like palladium-catalyzed phosphine-gold(I) halide elimination reactions with aryl iodides and redox-active tetrathiafulvalene (TTF) mono- and bisiodides. This presents a particularly convenient method for the preparation of symmetrical and asymmetrical tetrathiafulvalene (TTF)-fused radiaannulenes in good yields.
- Mazzanti, Virginia,Jiang, Huixin,Gotfredsen, Henrik,Morsing, Thorbjorn J.,Parker, Christian R.,Nielsen, Mogens Brondsted
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supporting information
p. 3736 - 3739
(2014/08/05)
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- Autotandem catalysis: Synthesis of pyrroles by gold-catalyzed cascade reaction
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A novel synthesis of substituted pyrroles by a gold(I)-catalyzed cascade reaction has been developed. The reaction proceeded with an autotandem catalysis consisting of an initial addition of gold-acetylide to an acetal moiety and was followed by gold-catalyzed 5-endo-dig cyclization and aromatization. Gold catalysts play a dual role in activating nucleophilicity or electrophilicity of terminal acetylenes by forming gold-acetylides or by π-coordination. The formal (3 + 2) annulation of two components provided a variety of substituted pyrroles in a modular fashion.
- Ueda, Hirofumi,Yamaguchi, Minami,Kameya, Hiroshi,Sugimoto, Kenji,Tokuyama, Hidetoshi
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supporting information
p. 4948 - 4951
(2015/04/27)
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- Exceptionally fast carbon-carbon bond reductive elimination from gold(III)
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Reductive elimination of carbon-carbon bonds occurs in numerous metal-catalysed reactions. This process is well documented for a variety of transition metal complexes. However, carbon-carbon bond reductive elimination from a limited number of Au(III) complexes has been shown to be a slow and prohibitive process that generally requires elevated temperatures. Herein we show that oxidation of a series of mono- and bimetallic Au(I) aryl complexes at low temperature generates observable Au(III) and Au(II) intermediates. We also show that aryl-aryl bond reductive elimination from these oxidized species is not only among the fastest observed for any transition metal, but is also mechanistically distinct from previously studied alkyl-alkyl and aryl-alkyl reductive eliminations from Au(III).
- Wolf, William J.,Winston, Matthew S.,Toste, F. Dean
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p. 159 - 164
(2014/02/14)
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