10008-73-8Relevant articles and documents
Self-assembled M12L24 nanospheres as a reaction vessel to facilitate a dinuclear Cu(i) catalyzed cyclization reaction
Gonell, Sergio,Caumes, Xavier,Orth, Nicole,Ivanovi?-Burmazovi?, Ivana,Reek, Joost. N. H.
, p. 1316 - 1321 (2019)
The application of large M12L24 nanospheres allows the pre-concentration of catalysts to reach high local concentrations, facilitating reactions that proceed through dinuclear mechanisms. The mechanism of the copper(i)-catalyzed cyclization of 4-pentynoic acid has been elucidated by means of a detailed mechanistic study. The kinetics of the reaction show a higher order in copper, indicating the formation of a bis-Cu intermediate as the key rate determining step of the reaction. This intermediate was further identified during catalysis by CIS-HRMS analysis of the reaction mixture. Based on the mechanistic findings, an M12L24 nanosphere was applied that can bind up to 12 copper catalysts by hydrogen bonding. This pre-organization of copper catalysts in the nanosphere results in a high local concentration of copper leading to higher reaction rates and turnover numbers as the dinuclear pathway is favored.
"water soluble" palladium nanoparticle engineering for C-C coupling, reduction and cyclization catalysis
Iben Ayad,Belda Marín,Colaco,Lefevre,Méthivier,Ould Driss,Landoulsi,Guénin
, p. 6646 - 6657 (2019)
The use of Pd nanoparticles (Pd-NPs) to realize several important organic reactions allows efficient catalysis with low metal loading (1000 ppm), hence providing a greener catalytic system. However, to be truly green Pd-NPs need to be synthesized in a sustainable manner and be able to react in aqueous media in order to avoid the use of organic solvents. Here we describe an original and eco-friendly synthesis of Pd-NPs (using benign reactants and simple conditions) perfectly stable in water. Remarkably, this synthesis allows for control over their size and morphology by simply tuning the pH of the stabilizer. We then evaluate the catalytic efficiency of these Pd-NPs on six different model reactions (Suzuki Miyaura, Sonogashira, Heck, nitrophenol reduction and pentynoic cycloisomerization) in aqueous media. We show that the stabilizer structure influences the activity owing to its ability to promote the mass transfer of the organic substrates towards the NP surface in the aqueous environment. Finally, catalytic evaluations show that our nano-catalysts prepared in an eco-friendly manner are among the best catalysts described so far in the literature in each case, with high turnover frequencies reached with a low loading of palladium.
Metal-ligand cooperation in the cycloisomerization of alkynoic acids with indenediide palladium pincer complexes
Nebra, Noel,Monot, Julien,Shaw, Rosie,Martin-Vaca, Blanca,Bourissou, Didier
, p. 2930 - 2934 (2013)
Indenediide Pd complexes 1a-c are shown to very efficiently catalyze the cycloisomerization of alkynoic acids into alkylidene lactones via metal-ligand cooperation (TON up to 2000). Complexes 1a-c are competent toward a broad range of alkynoic acids, including functionalized and internal ones, and give access to 5- as well as 6- and 7-membered lactones in excellent yields and with very high selectivities.
Gold Functionalized Platinum M12L24-Nanospheres and Their Application in Cyclization Reactions
Leenders, Stefan H. A. M.,Dürr, Maximillian,Ivanovic-Burmazovic, Ivana,Reek, Joost N. H.
, p. 1509 - 1518 (2016)
Nanospheres can be formed by combining 24 bispyridinyl building blocks with a palladium or platinum precursor. These spheres can be functionalized on the inside with a gold(I) chloride complex leading to a high local concentration of gold(I) complexes. The high local concentration makes the neutral gold species an active catalyst. Furthermore, the platinum-gold spheres can be post-modified with a silver(I) salt to form cationic gold(I) catalysts. The platinum assemblies are demonstrated to be stable in the presence of various substrates and as a result several cyclization reactions have been carried out using these new spheres as catalysts. Higher conversions in a [4+2] cycloaddition are observed for the sphere catalyst compared to the mono-nuclear analogues. Also the cyclization of 1,6-enynes can be facilitated by the confined gold catalyst and high activity is observed in the activation of allenes. For the lactonization of alkynoic acids, a different selectivity is observed compared to a standard gold(I) complex, demonstrating that the high local concentration due to a confined space can induce other selectivity in catalysis.
Synthesis and characterization of oxygen/sulfur-bridged incomplete cubane-type clusters, [M3S4(Tpe)3]+ and [M 3OS3(Tpe)3]+ (M = Mo and W), and a mixed-metal cubane-type cluster, [Mo3
Yoshida, Ryouichi,Shibahara, Takashi,Akashi, Haruo
, p. 839 - 849 (2013)
The reaction of [Mo3S4(H2O) 9]4+(1) and [Mo3OS3(H 2O)9]4+ (2) with hydrotris(pyrazolyl)ethanol (HTpe) ligands produced [Mo3S4/su
Enhanced catalytic performance of indenediide palladium pincer complexes for cycloisomerization: Efficient synthesis of alkylidene lactams
Espinosa-Jalapa, Noel ángel,Ke, Diandian,Nebra, Noel,Le Goanvic, Lucas,Mallet-Ladeira, Sonia,Monot, Julien,Martin-Vaca, Blanca,Bourissou, Didier
, p. 3605 - 3611 (2014)
New SCS Pd pincer complexes featuring a noninnocent indenediide backbone show high catalytic activity in cycloisomerization. A variety of alkylidene lactams (five- to seven-membered rings) have been prepared efficiently from N-tosyl alkynylamides, and goo
A case study of proton shuttling in palladium catalysis
Monot, Julien,Brunel, Paul,Kefalidis, Christos E.,Espinosa-Jalapa, Noel ángel,Maron, Laurent,Martin-Vaca, Blanca,Bourissou, Didier
, p. 2179 - 2187 (2016)
The mechanism of alkynoic acid cycloisomerization with SCS indenediide Pd pincer complexes has been investigated experimentally and computationally. These studies confirmed the cooperation between the Pd center and the backbone of the pincer ligand, and r
Sustainable Gold Catalysis in Water Using Cyclodextrin-tagged NHC-Gold Complexes
Sak, Hülya,Mawick, Matthias,Krause, Norbert
, p. 5821 - 5829 (2019)
The synthesis of 10 water-soluble β-cyclodextrin-tagged NHC-gold(I) complexes is described. Key steps are nucleophilic substitutions, as well as, copper-(CuAAC)- and ruthenium-(RuAAC)-catalyzed azide alkyne cycloadditions. Whereas the CuAAC reliably affor
Impregnated palladium on magnetite as a water compatible catalyst for the cycloisomerization of alkynoic acid derivatives
Saavedra, Beatriz,Pérez, Juana M.,Rodríguez-álvarez, María J.,García-álvarez, Joaquín,Ramón, Diego J.
, p. 2151 - 2157 (2018)
This work describes the catalytic activity of palladium(ii) species in the cycloisomerization of alkynoic acids and their derivatives in aqueous media as well as in Deep Eutectic Solvents (DESs), with one of the lowest metal catalyst loadings reported so far in the literature. Different substrates such as terminal and internal alkynes or alkynyl sulfonylimides were studied, obtaining selectivity either to the cyclic compound or the hydrolysed keto derivative. This new system avoids the use of harmful solvents and employs very efficient and recoverable heterogeneous catalysts.
SILVER ASSISTED HETEROCYCLIZATION OF ACETYLENIC COMPOUNDS
Pale, Patrick,Chuche, Josselin
, p. 6447 - 6448 (1987)
Silver assisted heterocyclization of acetylenic alcohols or acids provides an easy and mild access to α-methylene oxygenated heterocycles.
Symmetrical and Non-symmetrical Pd (II) Pincer Complexes Bearing Mesoionic N-heterocyclic Thiones: Synthesis, Characterizations and Catalytic Properties
Yan, Xuechao,Zhang, Bo,Zhang, Xin,Wang, Haiying,Duan, Yu-Ai,Guo, Shuai
, (2020)
In contrast to well-established symmetrical pincer complexes, non-symmetrical metal pincers with the loss of C2v symmetry are much less studied. In this work, mesoionic NHTs (NHTs = N-heterocyclic thiones), which can be viewed as the sulfur adducts of mesoionic carbenes, are incorporated into pincer complexes for the first time. Two symmetrical and non-symmetrical phenylene-bridged bis (NHT) compounds 3a/3b were synthesized as proligands via a “cycloaddition-alkylation-thionation” reaction sequence. In a case to access bis (NHT) compound 3c, N-dealkylation reactions occurred. The carbene NMR signals of NHTs are only partially correlated to the π-accepting abilities of carbenes, which is different from Bertrand's carbene-phosphinidene system. The structural analysis of 3a/3b indicates that they possess C-S partial double bonds. 3a and 3b served as the precursors to access two aryl anion-linked [SCS/S′] pincer complexes 6a/6b. An external base proved to be essential for this cyclopalladation process. The catalytic properties of 6a/6b in the cycloisomerizations of alkynoic acids have been examined. Finally, non-symmetrical complex 6a shows superior catalytic performance in such transformations contrasting to its symmetrical counterpart 6b.
Cu(I)-catalyzed intramolecular cyclization of alkynoic acids in aqueous media: A "click side reaction"
Mindt, Thomas L.,Schibli, Roger
, p. 10247 - 10250 (2007)
(Chemical Equation Presented) Alkynoic acids, in particular, 4-pentynoic acid derivatives, undergo intramolecular cyclizations to enol lactones under reaction conditions typically applied for the Cu(I)-catalyzed cycloaddition of terminal alkynes and azide
Atom transfer radical addition and enol-ester synthesis catalyzed by Ru-vinylidene complexes
Opstal, Tom,Verpoort, Francis
, p. 9259 - 9263 (2002)
Ru-vinylidene complexes, Cl2Ru{=C=C(H)tBut}(PCy3)(L) (L=PCy3 or N-heterocyclic carbenes) reveal themselves as a versatile catalyst for the atom transfer radical addition (ATRA) of polyhalogenated alkanes to olefins, such as methylmethacrylate, styrene and 1-octene. Furthermore, these systems are excellent catalysts for the nucleophilic addition of carboxylic acids to terminal alkynes and yielded exclusively alk-1-en-2-yl esters. These complexes can also be transformed to their cationic counterparts by treating the neutral complexes with AgBF4 and their catalytic potential in ATRA and vinylation reaction are investigated.
Copper-catalyzed tandem reaction in ionic liquid: An efficient reusable catalyst and solvent media for the synthesis of fused poly hetero cyclic compounds
Naidu, Shivaji,Reddy, Sabbasani Rajasekhara
, p. 62742 - 62746 (2016)
Herein we report a copper catalyzed tandem reaction for the synthesis of therapeutically important pyrrolo-/pyrido[2,1-b] benzo[d][1,3]oxazin-1-ones from 2-aminobezyl alcohols using alkynoic acids under ligand and base free conditions in the presence of a green solvent medium [bmim]OTf. The catalyst and solvent were successfully recycled and reused.
The phosphinoboration of 2-diphenylphosphino benzaldehyde and related aldimines
Kindervater, Meagan B.,Binder, Justin F.,Baird, Samuel R.,Vogels, Christopher M.,Geier, Stephen J.,Macdonald, Charles L.B.,Westcott, Stephen A.
, p. 378 - 385 (2019)
We have investigated the addition of a simple phosphinoboronate ester, Ph2PBpin (pin = 1,2-O2C2Me4), to 2-diphenylphosphinobenzaldehyde (2-Ph2PC6H4C(O)H) and related aldimine derivatives (2-Ph2PC6H4C(NR)H) as a simple and effective strategy for generating unique diphosphine ligands bearing a pendant Lewis-acid Bpin group. These reactions proceed selectively to give one new product where the phosphide fragment has added to the aldehyde (or imine) carbon atom and the electron-deficient boron group has added to the electron-rich heteroatom. Preliminary studies show these new compounds can ligate to Pd(II) and Pt(II) metal centres. These novel metal complexes, as well as the organic soluble [MCl2(coe)]2 (M = Pd, Pt, coe = cis-cyclooctene) compounds, have been shown to be effective precatalysts in the cyclisation of alkynoic acids to give the corresponding exo-dig cyclic lactones. Reactions employing these metal complexes also generated unusual endo-dig cyclic lactones not traditionally observed in these cyclisation reactions. For instance, reactions of 4-pentynoic acid also afforded significant amounts of α-angelica lactone, a biologically-important compound traditionally prepared via the catalytic dehydration and cyclisation of levulinic acid.
Efficient formation of angelica lactones in a vapor-phase conversion of levulinic acid
Sun, Daolai,Takahashi, Yuta,Yamada, Yasuhiro,Sato, Satoshi
, p. 62 - 69 (2016)
Vapor-phase lactonization of levulinic acid to produce angelica lactones, which include α-, β- and γ-form isomers, was performed in fixed-bed down-flow glass reactors over various oxide catalysts. SiO2 and SiO2-Al2O3 showed relatively high catalytic activity. The lactonization of levulinic acid to angelica lactones was found to be an endothermic equilibrium reaction, and the pressure equilibrium constant was calculated to be 0.2?atm at 275?°C. High temperatures and reduced pressures were effective for shifting the equilibrium from levulinic acid to angelica lactones, while the suitable reaction temperature was estimated to be 275?°C because temperatures higher than 275?°C decreased the selectivity to angelica lactones. The highest angelica lactones yield of 87.5% was achieved at a levulinic acid conversion of 95.3% over SiO2 under reduced pressure conditions of ca. 5?kPa at 275?°C. IR, NH3-TPD and TG analyses were performed for characterizing the catalysts used after the reactions together with a silylated SiO2 prepared for studying the active species on SiO2. The silanol groups of SiO2 with weak acidity were proposed to be the active species.
Ylide-Functionalized Phosphines: Strong Donor Ligands for Homogeneous Catalysis
Scherpf, Thorsten,Schwarz, Christopher,Scharf, Lennart T.,Zur, Jana-Alina,Helbig, Andreas,Gessner, Viktoria H.
, p. 12859 - 12864 (2018)
Phosphines are important ligands in homogenous catalysis and have been crucial for many advances, such as in cross-coupling, hydrofunctionalization, or hydrogenation reactions. Herein we report the synthesis and application of a novel class of phosphines bearing ylide substituents. These phosphines are easily accessible via different synthetic routes from commercially available starting materials. Owing to the extra donation from the ylide group to the phosphorus center the ligands are unusually electron-rich and can thus function as strong electron donors. The donor capacity surpasses that of commonly used phosphines and carbenes and can easily be tuned by changing the substitution pattern at the ylidic carbon atom. The huge potential of ylide-functionalized phosphines in catalysis is demonstrated by their use in gold catalysis. Excellent performance at low catalyst loadings under mild reaction conditions is thus seen in different types of transformations.
Mercuric triflate·3TMU catalyzed cyclization of ω-alkynoic acids and synthesis of a naturally occurring γ-methylene-γ-lactone
Imagawa, Hiroshi,Fujikawa, Yukari,Tsuchihiro, Atsushi,Kinoshita, Atsushi,Yoshinaga, Takayuki,Takao, Hiroko,Nishizawa, Mugio
, p. 639 - 641 (2006)
Hg(OTf)2·3TMU showed efficient catalytic activity for the cyclization of ω-alkynoic acid to give ω-methylene-ω-lactone in excellent yield, and the procedure was efficiently applied for the synthesis of naturally occurring γ-methylene-γ-lactone.
Relative thermodynamic stabilities of γ-methylene-γ-butyrolactone and α-angelicalactone
Taskinen, Esko
, p. 1885 - 1888 (1994)
The relative thermodynamic stabilities of the title compounds have been determined by chemical equilibration in cyclohexane and dipentyl ether solutions at several temperatures. In each solvent, α-angelicalactone is favored thermodynamically, the values of ΔH(θ) and ΔS(θ) being ca. -8.0 kJ mol-1 and 2 J K-1 mol-1, respectively, for the γ-methylene-γ- butyrolactone → α-angelicalactone isomerization.
Cu(I) Camphor Coordination Polymers: Synthesis and Study of the Catalytic Activity for Cyclization of 4-Pentyn-1-oic Acid
Fernandes, Tiago A.,Galvo, Adelino M.,Do Rego, Ana M. Botelho,Carvalho, M. Fernanda N. N.
, p. 3316 - 3323 (2014)
The number of CuCl units per camphor ligand in [{CuCl}2L]n was extended to three or four in [{CuCl}3L]n (2) or [{CuCl}4L]n (1). The Hartree-Fock ab initio calculations support the polymeric structure of 1 and 2 that catalyze the cyclization of 4-pentyn-1-
Redox-Switchable Cycloisomerization of Alkynoic Acids with Napthalenediimide-Derived N-Heterocyclic Carbene Complexes
Gonell, Sergio,Gutiérrez-Blanco, Ana,Peris, Eduardo,Poyatos, Macarena,Ruiz-Zambrana, César
, p. 20003 - 20011 (2021)
Two naphthalene-diimide (NDI) bis-imidazolium salts have been used as N-heterocyclic carbene (NHC) precursors for the preparation of NDI-functionalized complexes of rhodium and iridium of general formula [MCl(NDI-NHC)(COD)] (M=Rh, Ir; NDI-NHC=NDI-function
New reactions of anticancer-platinum complexes and their intriguing behaviour under various experimental conditions
Aleman, Jose,Del Solar, Virginia,Cubo, Leticia,Quiroga, Adoracion G.,Navarro Ranninger, Carmen
, p. 10601 - 10607 (2010)
The anticancer platinum complexes here described react with organic substrates (such as acids, alkenes, alkynes) and catalyze transformations that can occur in biomolecules which contain unsaturated functions. We have analyzed the role of the platinum complexes in the observed reactions and studied the progress of the detected transformations upon variation of the reaction conditions. The Royal Society of Chemistry 2010.
Intramolecular cyclization of γ-acetylenic acids using dendrimer-encapsulated Pd2+ catalysts
Maeno, Zen,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
, p. 947 - 954 (2012)
Polyamine dendrimer-encapsulated Pd2+ catalysts were prepared by complexation of PdCl2 with internal tertiary amino groups of the dendrimer. The fifth-generation Pd2+ dendrimer catalyst showed cooperative catalysis between Pd2+ species and the internal nanocavity consisting of regularly arranged tertiary amino groups to promote the intramolecular cyclization of γ-acetylenic acids efficiently.
