92-92-2Relevant articles and documents
A bimetallic complex containing a cyclopentadienyl-annulated imidazol-2-ylidene
Arduengo III, Anthony J.,Tapu, Daniela,Marshall, William J.
, p. 16400 - 16401 (2005)
A bimetallic carbene complex architecture that incorporates a cyclopentadienyl-annulated imidazol-2-ylidene moiety is characterized. The ligand architecture enables direct electronic interaction between the π- and σ-bonded metals. A preliminary example of aqueous Suzuki coupling employing a metallocene-fused imidazol-2-ylidene-derived catalyst is described. Copyright
Peptide template effects for the synthesis and catalytic application of Pd nanoparticle networks
Jakhmola, Anshuman,Bhandari, Rohit,Pacardo, Dennis B.,Knecht, Marc R.
, p. 1522 - 1531 (2010)
Translation of nanomaterials from spherical to other shapes has demonstrated property and activity enhancement for applications ranging from optics to catalysis. Unfortunately, synthetic techniques for the controlled production of shaped nanomaterials, which can employ harsh conditions, remains challenging. In contrast, the fabrication of nanostructures using peptides has achieved the generation of functionally active materials using bio-conditions; however, these methods are typically limited to spherical materials. By merging these techniques, the biomimetic/ambient production of functional, shaped nanostructures may be achieved. Here we present the fabrication of non-spherical Pd nanostructures prepared using a peptide template. By controlling the Pd: peptide ratio, the production of at least three different Pd morphologies is possible: nanoparticles, short linear nanoribbons, and nanoparticle networks. Furthermore, all of the materials are active for Stille C-coupling catalysis using aqueous and room temperature conditions at low Pd concentrations. The results suggest that both the zerovalent Pd materials and the ligand surface structure modulate the reactivity, which may be exploitable for optimal functionality. The Royal Society of Chemistry 2010.
Morton,Massengale,Richardson
, p. 126,128 (1940)
Photosensitizing properties of 2,4-dichlorobenzoic acid and chlorinated biphenyl carboxylic acids, potentially key components of chromophoric dissolved organic matter
Boreen, Anne L.,McNeill, Kristopher
, p. 4113 - 4115 (2005)
2,4-Dichlorobenzoic acid and a suite of models of chlorinated biphenyl carboxylic acids were found to be efficient sensitizers of the reactive oxygen species singlet oxygen (1O2). The Royal Society of Chemistry 2005.
G-/C-rich oligonucleotides stabilized pd nanocatalysts for the Suzuki coupling reaction under mild conditions
Li, Wei,Fu, Yingming,Fu, Yan,Wang, Xian,Zhang, Jinli
, p. 578 - 586 (2013)
Pd nanoparticles with narrow size distributions between 1.3 and 3.3 nm are prepared using G-/C-rich oligonucleotide as the template. These DNA-Pd nanoparticles efficiently catalyze the Suzuki coupling reaction and exhibit highly catalytic activities under mild conditions, which are greatly dependent upon the particle size of Pd nanoparticles besides the DNA sequence. For the coupling reaction of iodobenzene and phenylboronic acid at 60 C in the presence of KOH, it can be achieved high TOF value of 2646 mol biphenyl (mol Pd × h)-1 over AG22-Pd and 3640 mol biphenyl (mol Pd × h) -1 over CT22-Pd. Under the optimal experimental conditions, the yield of 100 % in biphenyl is obtained with only 0.0055 mol% AG22-Pd at 60 C for 1 h in the solvent of EtOH/H2O (1:2) using Na2CO3 or K2CO3 as the base. It is illustrated that G-/C-rich oligonucleotides are promising templates to modulate easily the morphology of Pd nanoparticles in aqueous solution with high catalytic activity.
Rapid and amenable Suzuki coupling reaction in water using microwave and conventional heating
Leadbeater, Nicholas E.,Marco, Maria
, p. 888 - 892 (2003)
It is possible to prepare biaryls in good yield very rapidy (5-10 min) on small (1 mmol) and larger (10-20 mmol) scales from aryl halides and phenylboronic acid using water as a solvent and palladium acetate as catalyst. The reaction can be performed equally well using microwave and conventional heating, showing that using these conditions probably no nonthermal microwave effects are associated with the impressive speed of the reaction.
Langmuir-Blodgett films of cyclopalladated ferrocenylimine: preparation, characterization, and application in Suzuki coupling reaction
Mu, Bing,Li, Tiesheng,Li, Chenghuan,Liu, Pingping,Shang, Wei,Wu, Yangjie
, p. 2599 - 2604 (2009)
Langmuir monolayer and Langmuir-Blodgett (LB) films of cyclopalladated ferrocenylimine 1 were prepared and characterized. The surface pressure (π)-area (A) isotherm of complex 1 indicated the formation of highly condensed monolayer on the subphase. Ultraviolet-visible (UV-vis) and Fourier transform infrared (FTIR) spectroscopy showed that complex 1 monolayer was transferred successfully onto solid supports. Atomic force microscopy (AFM) image suggested that LB films transferred on the solid substrate were well-ordered, homogeneous. Cyclic voltammograms of LB films deposited on glassy carbon electrodes showed quasi-reversible oxidation/reduction waves of ferrocene moiety. From the average thickness of monolayer, the hydrocarbon chain could be fairly directed perpendicular to the substrates. Finally, LB films of complex 1 presented a largely improved catalytic efficiency for Suzuki reaction with respect to its cast films and homogeneous reactions under the same conditions. The results might have an implication on the catalytic mechanism of this reaction.
Transformation of Thioacids into Carboxylic Acids via a Visible-Light-Promoted Atomic Substitution Process
Fu, Qiang,Liang, Fu-Shun,Lou, Da-Wei,Pan, Gao-Feng,Wang, Rui,Wu, Min,Xie, Kai-Jun
supporting information, p. 2020 - 2024 (2022/03/31)
A visible-light-promoted atomic substitution reaction for transforming thiocacids into carboxylic acids with dimethyl sulfoxide (DMSO) as the oxygen source has been developed, affording various alkyl and aryl carboxylic acids in over 90% yields. The atomic substitution process proceeds smoothly through the photochemical reactivity of the formed hydrogen-bonding adduct between thioacids and DMSO. A DMSO-involved proton-coupled electron transfer (PCET) and the simultaneous generation of thiyl and hydroxyl radicals are proposed to be key steps for realizing the transformation.
An Anionic, Chelating C(sp3)/NHC ligand from the Combination of an N-heterobicyclic Carbene and Barbituric Heterocycle
Benaissa, Idir,Gajda, Katarzyna,Vendier, Laure,Lugan, No?l,Kajetanowicz, Anna,Grela, Karol,Michelet, Véronique,César, Vincent,Bastin, Stéphanie
, p. 3223 - 3234 (2021/09/30)
The coordination chemistry of the anionic NHC1-based on an imidazo[1,5-a]pyridin-3-ylidene (IPy) platform substituted at the C5 position by an anionic barbituric heterocycle was studied with d6(Ru(II), Mn(I)) and d8(Pd(II), Rh(I), Ir(I), Au(III)) transition-metal centers. While the anionic barbituric heterocycle is planar in the zwitterionic NHC precursor 1·H, NMR spectroscopic analyses supplemented by X-ray diffraction studies evidenced the chelating behavior of ligand 1-through the carbenic and the malonic carbon atoms in all of the complexes, resulting from a deformation of the lateral barbituric heterocycle. The complexes were obtained by reaction of the free carbene with the appropriate metal precursor, except for the Au(III) complex 10, which was obtained by oxidation of the antecedent gold(I) complex [AuCl(1)]?with PhICl2as an external oxidant. During the course of the process, the kinetic gold(I) intermediate 9 resulting from the oxidation of the malonic carbon of the barbituric moiety was isolated upon crystallization from the reaction mixture. The νCOstretching frequencies recorded for complex [Rh(1)(CO)2] (5) demonstrated the strong donating character of the malonate-C(sp3)/NHC ligand 1-. The ruthenium complex [Ru(1)Cl(p-cymene)] (11) was implemented as a precatalyst in the dehydrogenative synthesis of carboxylic acid derivatives from primary alcohols and exhibited high activities at low catalyst loadings (25-250 ppm) and a large tolerance toward functional groups.