17057-88-4Relevant academic research and scientific papers
Ligand-promoted oxidative cross-coupling of aryl boronic acids and aryl silanes by palladium catalysis
Yu, Jingxun,Liu, Jun,Shi, Guangfa,Shao, Changdong,Zhang, Yanghui
, p. 4079 - 4082 (2015)
The first cross-coupling reaction between aryl silanes and aryl boronic acids is described. This transformation represents one of the very few examples of coupling reactions between two nucleophilic organometallic reagents and provides a new method for the formation of biaryl compounds. The successful development of this reaction was enabled by the use of commercially available 2,2-bis(diphenylphosphino)-1,1-binaphthyl (BINAP) as the ligand. A small amount of BINAP (3 mol %) was sufficient to suppress the formation of the homocoupling products, and the reaction yielded the cross-coupling products with high selectivity under mild conditions, even when the ratio of the two coupling partners was 1:1.
Phenylphosphinacalix[3]trifuran: Synthesis, coordination and application in the Suzuki-Miyaura cross-coupling reaction in water
Sun, Yue,Yan, Meng-Qi,Liu, Yan,Lian, Ze-Yu,Meng, Tong,Liu, Sheng-Hua,Chen, Jian,Yu, Guang-Ao
, p. 71437 - 71440 (2015)
Phenylphosphinacalix[3]trifuran and supramolecular assemblies with palladium have been synthesized. Phenylphosphinacalix[3]trifuran affords turnover numbers as high as 3.05 × 107 in Suzuki-Miyaura cross-coupling reactions in pure water.
PH-Induced Linkage Isomerism of Pd(II) Complexes: A Pathway to Air- and Water-Stable Suzuki-Miyaura-Reaction Catalysts
Walczak, Anna,Stefankiewicz, Artur R.
, p. 471 - 477 (2018)
The Pd(II) complexes of the ambidentate pyridyldiketones 2,2-dimethyl-5-(3- or 4-pyridyl)pentane-3,5-dione are readily prepared in their linkage isomeric forms by the appropriate pH control during syntheses. The isolated diketonate- or pyridine-bound species can be interconverted with essentially 100% efficiency by treatment with an acid or base, respectively. Under the normal basic conditions for a Suzuki-Miyaura coupling, only the diketonate forms are present and act as very efficient catalysts for this reaction. The dynamic nature of the presented complexes allows the catalytic process to be quenched and reactivated at any stage without the risk of losing the catalyst's activity.
Palladium/P,O-Ligand-Catalyzed Suzuki Cross-Coupling Reactions of Arylboronic Acids and Aryl Chlorides. Isolation and Structural Characterization of (P,O)-Pd(dba) Complex
Bei, Xiaohong,Turner, Howard W.,Weinberg, W. Henry,Guram, Anil S.,Petersen, Jeffrey L.
, p. 6797 - 6803 (1999)
The phenyl backbone-derived P,O-ligands 1 and 2 were investigated for their utility as ligands in palladium/ligand-catalyzed Suzuki reactions. The 2-(2′-dicyclohexylphosphinophenyl)-2-methyl-1,3-dioxolane (ligand 1) in combination with Pd(dba)2 affords an efficient catalyst for general Suzuki reactions of a wide variety of arylboronic acids and aryl chlorides, bromides, and iodides to afford the desired biaryl products in high isolated yields. Arylboronic acids and aryl chlorides containing electron-poor, electron-rich, and ortho substituents participate effectively. In contrast, the structurally related ligand 2-(2′-dicyclohexylphosphinophenyl)-1,3-dioxolane (ligand 2) was found to be less efficient under similar conditions. The reaction of ligand 1 with Pd(dba)2 affords the complex LPd-(dba) (14, L = 1). The NMR spectroscopic and X-ray crystallographic data of complex 14 establish that ligand 1 functions as a P,O-chelating ligand in complex 14. The reaction of ligand 2 (2 equiv) with Pd(dba)2 and excess 4-tBu-C6H4Br or the ligand displacement reaction of {Pd[P(o-tolyl)3](4-tBu-C6H4)(μ-Br)} 2 with ligand 2 affords the bis-phosphine complex L2Pd(4-tBu-C6H4)(Br) (13, L = 2). The NMR spectroscopic data of complex 13 establish that ligand 2 in complex 13 functions as a nonchelating ligand. Thus, the higher efficiency of ligand 1 over ligand 2 in Pd/L-catalyzed Suzuki arylation of aryl chlorides can be ascribed to the ability of ligand 1 to generate and stabilize monophosphine P,O-chelating Pd/L intermediates, which appear to be most suitable for Suzuki arylation reactions involving certain substrates and conditions.
A novel P,S-heterodonor ligand and palladium(0) complex catalyzed Suzuki cross-coupling reaction
Zhang, Wen,Shi, Min
, p. 8921 - 8924 (2004)
In the presence of a novel P,S-heterodonor ligand, palladium(0)-catalyzed Suzuki cross-coupling reaction proceeded smoothly at 80°C in DMSO. Axially dissymmetric P,S-heterodonor ligand L3 synthesized from BINOL is an effective promoter in the palladium(0)-catalyzed Suzuki cross-coupling reaction of phenylboronic acid with aryl bromides and iodide at 60-80°C. On the basis of 13C and 31P NMR spectroscopic investigation and X-ray diffraction, it was revealed that N,N-dimethylthiocarbamate-phosphine ligand L3 might be a P,S-heterodonor bidentate ligand to palladium(0) center.
Phosphaalkenes palladium(II) complexes in the Suzuki and Sonogashira cross-coupling reactions
Deschamps, Bernard,Le Goff, Xavier,Ricard, Louis,Le Floch, Pascal
, p. 363 - 371 (2007)
The 1-methoxy-2-(supermesitylphos-phanylidenemethyl)-benzene ligand (1) was prepared by reacting the phospha-Wittig reagent [Mes*P=PMe3] with o-methoxybenzaldehyde. Reaction of 1 with one equivalent of the [Pd(allyl)Cl]2 aimer in the presence of Ag(OTf) affords a neutral complex (4) in which the triflate ligand is coordinated to the palladium atom. DFT calculations show that the formation of complex 4 is favored by 22.4 kcal/mol with respect to that of a chelate species involving coordination of the ligand through the phosphorus atom of one lone pair at the oxygen of the pendant methoxy group. Reaction of two equivalents of ligand 1 with the [Pd(allyl)Cl]2 dimer affords complex 5, in which the two ligands are coordinated through their phosphorus atom. The catalytic activity of complex 5 was compared to that of the 1, 3-bis[2-(supermesityl)phosphanediylmethyl]benzene palladium chloride complex (6). Performances of the two catalysts were found to be similar in the Suzuki cross-coupling reaction between phenylboronic acid and some arylbromides (TON between 55.105 and 99.105) as well as in the Sonogashira coupling between phenylacetylene and arylbromides (TON between 400 and 950).
Porous Organic Phenanthroline-Based Polymer as an Efficient Transition-Metal-Free Heterogeneous Catalyst for Direct Aromatic C?H Activation
Tang, Yongquan,Chen, Fang,Wang, Sai,Sun, Qi,Meng, Xiangju,Xiao, Feng-Shou
, p. 8684 - 8688 (2021)
Direct C?H bond transformation has been regarded as one of the most important areas in organic synthesis in both academia and industry. However, the heterogeneous transition-metal-free catalysis of direct C?H bond transformation has remained a contemporary challenge. To tackle this challenge, we designed and constructed a porous phenanthroline-based polymer (namely POP-Phen) via free radical polymerization of vinyl-functionalized phenanthroline monomers. POP-Phen shows excellent catalytic performances in transition-metal-free catalyzed C?H arylation, even better than those of the corresponding homogeneous catalyst, which is mainly attributed to the high density of catalytically active sites in the heterogeneous catalyst. Kinetic isotope experiments and spectral characterizations demonstrate the electron-transfer between the heterogeneous catalyst and the base (t-BuOK), a key step for C?H activation. We believe that this porous organic phenanthroline polymer could open a new door for the design of novel heterogeneous transition-metal-free catalysts for direct C?H activation.
Ossification: A new approach to immobilize metal complex catalysts-applications to carbonylation and Suzuki coupling reactions
Sarkar, Bibhas R.,Chaudhari, Raghunath V.
, p. 231 - 238 (2006)
A simple approach for immobilization of transition metal complexes is reported here based on the transformation of the complex into its intrinsically insoluble counterpart, thus generating solid molecular catalysts. This approach that we call "ossification" is based on a principle, in which the water-soluble analogues of the metal complexes are precipitated out from aqueous solutions as insoluble ionic ensembles having catalytically active metal-centered coordination environments and robust framework. The approach has been illustrated for Pd complex catalyzed carbonylation and Suzuki coupling reactions. "Ossification" was found to be an economically and environmentally attractive alternative to other exotic immobilization methodologies.
Hydrodefluorinations of trifluorotoluenes by LiAlH4 and TiCl4
Akiyama, Takahiko,Atobe, Kohei,Shibata, Michiko,Mori, Keiji
, p. 81 - 83 (2013)
In the presence of 2 mol% of TiCl4, α,α,α- trifluorotoluene derivatives were reduced with LiAlH4 to furnish toluene derivatives in high yields. Selective reduction of bis(trifluoromethyl) benzene derivative is effected. The difference of the reactivity between TiCl4 and NbCl5 is also discussed.
Palladium Supported on Metformin-Functionalized Magnetic Polymer Nanocomposites: A Highly Efficient and Reusable Catalyst for the Suzuki–Miyaura Coupling Reaction
Yang, Pengbo,Ma, Rong,Bian, Fengling
, p. 3746 - 3754 (2016)
In this paper, a novel magnetically responsive nanocatalyst, Pd/Fe3O4@PMAA-Met (PMAA=poly(methacrylic acid), Met=metformin), has been successfully prepared by immobilizing palladium on the surface of metformin-functionalized magnetic polymer nanocomposites. This novel nanocatalyst was characterized by FTIR, XRD, TEM, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). The prepared nanocatalyst showed excellent catalytic activity for Suzuki–Miyaura coupling reactions of aryl halides (I, Br, Cl) with arylboronic acids even at palladium loadings of 0.01–0.0007 mol % and the turnover frequency (TOF) reached up to 125 714 h?1. The excellent activity of this Pd/Fe3O4@PMAA-Met catalyst could be attributed to a “release and catch” catalytic mechanism as well as its nanometer size. This nanocatalyst could be simply separated with an external magnet and reused at least twelve times with excellent yields achieved.
