Search results for "Phenylacetylene"
showing 10 items of 36 documents
Rapid one-pot propargylamine synthesis by plasmon mediated catalysis with gold nanoparticles on ZnO under ambient conditions
2013
Surface plasmon excitation of gold nanoparticles on ZnO in the presence of an aldehyde, an amine and phenylacetylene led to rapid and selective formation of propargylamines with good yields (50-95%) at room temperature. Plasmon mediated catalysis is the best available route for this ternary coupling.
A New Heterogeneous Catalyst Obtained via Supramolecular Decoration of Graphene with a Pd2+ Azamacrocyclic Complex
2019
A new G-(H2L)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, in water at room temperature, of a macrocyclic H2L ligand on graphene (G) (G + H2L = G-(H2L)), followed by decoration of the macrocycle with Pd2+ ions (G-(H2L) + Pd2+ = G-(H2L)-Pd) under the same mild conditions. This supramolecular approach is a sustainable (green) procedure that preserves the special characteristics of graphene and furnishes an efficient catalyst for the Cu-free Sonogashira cross coupling reaction between iodobenzene and phenylacetylene. Indeed, G-(H2L)-Pd shows an excellent conversion (90%) of reactants into diphenylacetylene under mild conditio…
Chiral diphosphine derivatives of alkylidyne tricobalt carbonyl clusters – A comparative study of different cobalt carbonyl (pre)catalysts for (asymm…
2016
Reaction of the tricobalt carbyne cluster [Co-3(mu(3)-CH)(CO)(9)] with chiral diphosphines of the Josiphos and Walphos families affords the new clusters [Co-3(mu(3)-CH)(CO)(7)(P-P*)] in good yield (P-P* = J004 (1), J005 (2), J007 (3), W001 (4), W003 (5)). The new alkylidyne tricobalt clusters, and the previously known [Co-3(mu(3)-CH)(CO)(7)(mu-J003)], have been tested as catalysts/catalyst precursors for intermolecular Pauson-Khand cyclization, using norbornene and phenylacetylene as substrate. The diphosphine-substituted tricobalt carbonyl clusters proved to be viable catalysts/catalyst precursors that gave products in moderate to good yields, but the enantiomeric excesses were low. When t…
Synthesis and luminescence of poly(phenylacetylene)s with pendant iridium complexes and carbazole groups
2010
Poly(phenylacetylene)s containing pendant phosphorescent iridium complexes have been synthesized and their electrochemical, photo- and electroluminescent properties studied. The polymers have been synthesized by rhodium-catalyzed copolymerization of 9-(4-ethynylphenyl)carbazole (CzPA) and phenylacetylenes (C∧N)2Ir(κ2-O,O′-MeC(O)CHC(O)C6H4CCH-4) (C∧N = κ2-N,C1-2-(pyridin-2-yl)phenyl (IrppyPA) or κ2-N,C1-2-(isoquinolin-1-yl)phenyl (IrpiqPA)). In addition, organic poly(phenylacetylene)s with pendant carbazole groups have been synthesized by rhodium-catalyzed copolymerization of CzPA and 1-ethynyl-4-pentylbenzene. Complex (C∧N)2Ir(κ2-O,O′-MeC(O)CHC(O)Ph) (IrpiqPh; C∧N = 2-(isoquinolin-1-yl)phen…
Heterogeneous Sonogashira Coupling over Nanostructured SiliaCat Pd(0)
2012
Sol–gel entrapped catalyst SiliaCat Pd(0) heterogeneously mediates the Sonogoashira coupling of different aryl halides and phenylacetylene either under thermal conditions or, much more efficiently, under microwave irradiation, affording good conversions of coupled products. Leaching of valued Pd is limited, and the catalyst can be reused.
Bulky Surface Ligands Promote Surface Reactivities of [Ag141X12(S-Adm)40]3+ (X = Cl, Br, I) Nanoclusters: Models for Multiple-Twinned Nanoparticles
2017
Surface ligands play important roles in controlling the size and shape of metal nanoparticles and their surface properties. In this work, we demonstrate that the use of bulky thiolate ligands, along with halides, as the surface capping agent promotes the formation of plasmonic multiple-twinned Ag nanoparticles with high surface reactivities. The title nanocluster [Ag141X12(S-Adm)40]3+ (where X = Cl, Br, I; S-Adm = 1-adamantanethiolate) has a multiple-shell structure with an Ag71 core protected by a shell of Ag70X12(S-Adm)40. The Ag71 core can be considered as 20 frequency-two Ag10 tetrahedra fused together with a dislocation that resembles multiple-twinning in nanoparticles. The nanocluster…
Cu(I) complexes with diethoxyphosphoryl-1,10-phenanthrolines in catalysis of C–C and C–heteroatom bonds formation
2015
Abstract Diethoxyphosphoryl substituted 1,10-phenanthroline copper(I) complexes were tested as catalysts in the Sonogashira-type reaction, α-arylation of phosphoryl-stabilized C–H acids, C–N, C–P bond forming reactions (substitution reactions) and in the reaction of phenylacetylene and bis(pinacolato)diboron (addition reaction). The complexes demonstrate fairly high catalytic activity and in some cases their efficiency is superior to that of the parent Cu(phen)(PPh 3 )Br (phen = phenanthroline).
An Unprecedented Iridium(III) Catalyst for Stereoselective Dimerisation of Terminal Alkynes
2008
A novel iridium(III) hydride complex, IrHCl(TIMP 3 ) {HTIMP 3 = tris[1-(diphenylphosphino)-3-methyl-lH-indol-2-yl]methane) was prepared and fully characterized in both the solid state and in solution. Chloride abstraction by silver cations provides a more reactive compound, [IrH-(TIMP 3 )][BF 4 ], which can react with pyridine (py) and phenylacetylene to yield the complexes [IrH-(TIMP 3 )(py)][BF 4 ] and [Ir(PhCH=C-CH=CHPh)-(TIMP 3 )][BF 4 ], respectively. Interestingly, IrH-(TIMP 3 )(py)][BF 4 ] efficiently catalyses the stereoselective dimerisation of model terminal alkynes to the 1,4-disubstituted (E)-but-1-en-3-yne only.
Zirconium, hafnium and yttrium complexes containing two linked amido— tetramethylcyclopentadienyl ligands: Synthesis, reactivity and molecular struct…
1998
Abstract Zirconium and hafnium complexes M(η5: η1−C5Me4SiMe2NR′)xCl(4−2x) (M = Zr, Hf; x = 1, 2; R′ = iPr, tBu) containing one or two linked amido-tetramethylcyclopentadienyl ligands C5Me4SiMe2NR′ have been synthesized by the reaction of the dilithium derivative Li2(C5Me4SiMe2NR′) with MCl4(THF)2. The crystal structure of the hafnium complex Hf(η5: η1−C5Me4SiMe2NiPr)2 has been determined by a single-crystal X-ray diffraction study and shows a C2-symmetric helical metallocene, in which the amido ligands are bonded as π-donor ligands with Hf—N bond lengths of 2.115(2) A. The isoelectronic heterobimetallic yttrium complex Li[Y(η5: η1−C5Me4SiMe2NCH2CH2OMe)2] reacts with phenylacetylene to give …
Experimental and theoretical study of the [3+2] cycloaddition of carbonyl ylides with alkynes
2012
[EN] The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and alkynes (phenylacetylene, methyl propiolate, methyl but-2-ynoate and methyl 3-phenylpropiolate) to give substituted 2,5-dihydrofurans was investigated. The effect of indium(III) chloride on the outcome of the reaction was studied in the case of phenylacetylene and methyl propiolate. The thermal reaction between the carbonyl ylide coming from 2,2-dicyano-3-phenyloxirane and both methyl propiolate and methyl but-2-ynoate was theoretically investigated using DFT methods in order to explain the reactivity and regioselectivity observed.