Phenylacetylene Derivatives Research Articles

Stimuli-responsive poly(phenyl acetylene) microparticles with tunable chirality

Chiral polymeric microparticles combine the characteristics of chirality and spherical morphology in one matter, which may provide confined microenvironments to switch chirality and to promote conformation transition. Here we report on fabrication of chiral polymeric microparticles (CMPs) from dendronized copolymers, and investigation of their tunable chirality upon external stimuli, such as temperature, pH, metal ion complexation and solvents. These polymeric microparticles were constructed via one-pot approach through precipitation copolymerization of phenylacetylene derivatives. The monomers contain dendritic oligoethylene glycol (OEG) to afford copolymers thermoresponsiveness and alkynyl groups for polymerization and crosslinking. Chirality of the polymeric microparticles was afforded by intrinsic chirality from the amino acid moieties. Furthermore, thermoresponsiveness of these microparticles paves a novel route to switch their chirality and mediate their responsive behavior to metal ion coordination.

Semihydrogenation of phenylacetylene over nonprecious Ni-based catalysts supported on AlSBA-15

A series of nonprecious monometallic Ni/AlSBA-15 and bimetallic NiM (M = Zn, Ga, Cu, or Fe)/AlSBA-15 catalysts were prepared using a urea precipitation method and applied to the semihydrogenation of phenylacetylene. The catalysts were characterized by various techniques, showing that the Ni particle size of catalyst can be tuned by adjusting the Al content, and NiZn and NiGa supported catalysts exhibited geometric and electronic effects that originated from the bimetallic alloy. Among all the catalysts studied, NiZn3/AlSBA-15, with a turnover frequency of 10.89 s−1 comparable to that of precious Pd-based catalysts, presented the highest selectivity to styrene (90.3%) at nearly 100% conversion of phenylacetylene in semibatch operation. This catalyst was further evaluated in a continuous fixed-bed reactor for semihydrogenation of a model C8 aromatic fraction of pyrolysis gasoline (a mixture of phenylacetylene, styrene, ethylbenzene and xylene), which aimed at assessing its practical application of recovering styrene from pyrolysis gasoline. The results showed that at complete conversion of phenylacetylene, the styrene concentration in the product was always kept at a stable level and higher than its initial concentration over 100 h of time on stream, demonstrating high selectivity and good stability of NiZn3/AlSBA-15. Finally, the application of NiZn3/AlSBA-15 was extended to other phenylacetylene derivatives.

A BODIPY-functionalized PdII photoredox catalyst for Sonogashira C-C cross-coupling reactions.

We report for the first time a BODIPY-functionalized dichloro(1,10-phenanthroline)palladium(ii) complex as an efficient photoredox catalyst for the Sonogashira C-C cross-coupling between phenylacetylene derivatives and iodobenzene derivatives with yields up to 92% under visible light illumination at room temperature.

Visible light-driven cross-coupling reactions of alkyl halides with phenylacetylene derivatives for C(sp3)-C(sp) bond formation catalyzed by a B12 complex.

Visible light-driven cross-coupling reactions of alkyl halides with phenylacetylene and its derivatives catalyzed by the cobalamin derivative (B12) with the [Ir(dtbbpy)(ppy)2]PF6 photocatalyst at room temperature are reported. The robust B12 catalyst and Ir photocatalyst provided high turnover numbers of over 33 000 for the reactions.

Hydroaminocarbonylation of Alkynes to Produce Primary α,β‐Unsaturated Amides Using NH4HCO3 Dually as Ammonia Surrogate and Brønsted Acid Additive

AbstractBy using NH4HCO3 dually as ammonia surrogate and Brønsted acid additive, the production of primary α,β‐unsaturated amides via hydroaminocarbonylation of alkynes was accomplished efficiently. The advantages of using the solid and inexpensive NH4HCO3 included: (1) the facile and clean manipulation without presence of stinky gaseous NH3 or liquids organic amines, (2) the inhibition of the subsequent dehydration and hydrolysis of amides due to its weak basicity, and (3) the facilitated formation of Pd−H catalytic active species by the released H2CO3 serving as a weak Brønsted acid additive. In addition, the diphopshine of Dppp with the natural bite angle (βn) of 91° was found indispensable to spur the performance of the palladium catalyst for this reaction. Both terminal and internal phenylacetylene derivatives could be used as the substrates, affording the corresponding primary α,β‐unsaturated amides in good yields along with excellent regio‐selectivities to the branched ones.

Synthesis and antimicrobial screening of 2-alkyl(aryl)-7-chloro-6-fluoro-4-(trifluoromethyl)-quinolines and their phenylacetylene derivatives, promoted by Sonogashira cross-coupling reaction

This paper firstly describes the synthesis of a series of (Z)-4-((3-chloro-4-fluorophenyl)amino)-1,1,1-trifluorobut-3-en-2-ones (3a–f) as well as 1-(1-((3-chloro-4-fluorophenyl)amino)-3,4-dihydronaphthalen-2-yl)-2,2,2-trifluoroethanone (3g), from the O,N-exchange reaction of some 4-methoxy-4-alkyl(aryl)-1,1,1-trifluoroalk-3-en-2-ones (1) with 3-chloro-4-fluoroaniline (2), at 70–90% yields. Subsequently, in concentrated sulfuric acid, the enaminoketones 3 underwent a successful and regioselective intramolecular cyclocondensation reaction, which furnished a novel series of 2-alkyl(aryl)-7-chloro-6-fluoro-4-(trifluoromethyl)-quinolines (4) at 70–85% yields. To demonstrate synthetic applicability through the Sonogashira coupling reaction for obtaining quinolines with potential antimicrobial activity, the synthesis of a novel series of 2-alkyl(aryl)-6-fluoro-7-(phenylethynyl)-4-(trifluoromethyl)-quinolines (5) was performed, using quinolines 4 and phenylacetylene, via a regioselective Sonogashira coupling reaction (25–50% yield). Unfortunately, the new series of heterocycles 4 and 5 did not produce significant results against bacteria and fungi at the concentrations of 80–0.31μg/mL.

Synthesis of functionalized unsymmetrical 1,3-butadiene-3-yne derivatives from β-halo styrene derivatives and their application in the synthesis of trisubstituted pyridines

An approach for the synthesis of functionalized unsymmetrical 1,3-butadiene-3-yne derivatives is reported starting from β-halo styrene and phenyl acetylene derivatives in the presence of PdCl2 and CuI catalysts.

Turn-on fluorescent sensor for the detection of cyanide based on a novel dicyanovinyl phenylacetylene

A novel phenylacetylene derivative (3) was successfully synthesized via Sonogashira coupling and a Knoevenagel reaction for cyanide ion detection.

ChemInform Abstract: Palladium‐Free Sonogashira‐Type Cross‐Coupling Reaction of Bromoisoxazolines or N‐Alkoxyimidoyl Bromides and Alkynes.

AbstractThe newly developed protocol employs catalytic amount of Cu(I), a non‐toxic phenanthroline‐type ligand and tolerates a range of electron‐poor and electron‐rich phenylacetylene derivatives as well as aliphatic acetylenes (II).

Synthesis and Properties of Substituted Polyacetylenes Containing Pyrene Moieties in the Side Group

Abstract A novel phenylacetylene derivative containing a pyrene group was synthesized and polymerized with various Rh complex catalysts. The obtained polymers were soluble in common organic solvents such as chloroform and THF. The Mw and Mw/Mn were estimated as ca. 12000–18000 and 1.3–1.7 respectively, and the polymer yields were estimated as around 57–72%. The characteristic absorptions of ≡C–H (3200 cm−1) and C≡C (2100 cm−1) stretchings seen in the monomer spectra have completely disappeared in the polymer spectra from IR spectrum. 1H NMR analysis confirmed that the acetylene triple bonds transformed to polyene double bonds. These polymers were found to be thermally stable based on TGA data. The synthesized polymers exhibited blue fluorescence. The fluorescence quantum yield in solution was high at 0.37–0.41. Furthermore, the obtained polymer had a long fluorescence lifetime.

ChemInform Abstract: Cobalt‐Catalyzed Cross‐Coupling of Organozinc Halides with Bromoalkynes.

AbstractHighly substituted phenylacetylene derivatives are synthesized by using title method.

Fluorescent phenylethynylene calix[4]arenes for sensing TNT in aqueous media and vapor phase

The upper-rim of calix[4]arene is modified with phenylacetylene derivatives via Sonogashira coupling reaction to produce a wider cavity for entrapping TNT.

Dithiafulvenyl-substituted phenylacetylene derivatives: synthesis and structure-property-reactivity relationships.

A series of regioisomers for dithiafulvenyl-substituted phenylacetylene derivatives was synthesized and characterized to show structure-dependent electronic properties and different reactivities in their oxidized states.

ChemInform Abstract: Synthesis of Imidazo[1,2‐a]pyridine in the Presence of Iodine—Water Catalytic System.

AbstractImidazo[1,2‐a]pyridines are prepared in an eco‐friendly multicomponent reaction from 2‐aminopyridine, benzaldehyde and phenylacetylene derivatives in good yields.

Synthesis, chiroptical properties of a helical polyacetylene derivative carrying urea moieties

A novel phenylacetylene derivative containing urea groups was synthesized and polymerized with a Rh catalyst to give the corresponding polymer, poly(1) with moderate number-average molecular weights. The poly(1) was soluble in toluene, CHCl3, CH2Cl2, THF, DMF, and DMSO, but insoluble in hexane, diethyl ether and MeOH. The specific rotation and circular dichroism (CD) spectroscopic studies revealed that poly(1) took predominantly one-handed helical structures. The presence of intramolecular hydrogen bonding was confirmed by liquid-state IR spectroscopy. The helicity of poly(1) could be tuned by temperature and anion. The helical conformation of the polymer was stable against Br- but susceptible to F−.

Compelling mechanistic data and identification of the active species in tungsten-catalyzed alkyne polymerizations: conversion of a trianionic pincer into a new tetraanionic pincer-type ligand

Complex [tBuOCO]WC(tBu)(THF)2 (1) {where tBuOCO = [2,6-(tBuC6H3O)2C6H3]3−, THF = tetrahydrofuran} polymerizes acetylenes (R-phenylacetylene (R = H, p-OMe, p-F, 3,5-diCF3), 1-decyne, 3,3-dimethyl-1-butyne, and trimethylsilylacetylene) to form π-conjugating polymers. Upon treating 1 with 2 equiv. of phenylacetylene in toluene-d8 at −35 °C, two isolable products form. These two products are [O2C(tBuC)W(η2-HCCPh)] (2-tttBu) and [O2C(PhC)W(η2-HCCtBu)] (2-Ph) {where OC(tBuC)O = [2,6-(tBuC6H3O)2C6H3(tBuC)]4−, OC(PhC)O = [2,6-(tBuC6H3O)2C6H3(PhC)]4−} and derived from an apparent reductive alkylidyne migratory insertion into a metal–arene bond. Complexes 2-tttBu and 2-Ph polymerize acetylene and a wide variety of monosubstituted acetylenes including phenylacetylene derivatives, 1-decyne, 3,3-dimethyl-1-butyne and trimethylsilylacetylene. With a substrate to catalyst loading ratio of 25 000 : 1, complex 2-tttBu polymerizes phenylacetylene with a turnover number (TON) of 17 233. Additionally, 2-tttBu polymerizes phenylacetylene and 1-decyne with catalytic activities up to 5.64 × 106 gPPA mol−1 h−1 and 7.98 × 106 gPA mol−1 h−1, respectively. 2-tttBu also polymerizes the disubstituted acetylene, 1-phenyl-1-propyne. NMR spectroscopic and single crystal X-ray structural studies provide compelling evidence for polymer chain growth via an insertion ring-expansion mechanism.

Synthesis of Cyclotriveratrylene–Phenylacetylene Derivatives and a Photophysical Investigation of Rigid Conjugated Cyclotriveratrylene Dendrimers

AbstractVarious functionalized host molecules and building blocks can be derived from the cone‐shaped cyclotriveratrylene (CTV). In this article, we report on the synthesis of CTV‐I3 derivatives 3a and 3b and their Sonogashira cross‐coupling with various terminal aryl‐alkynes, to synthesize CTV‐phenylacetylene derivatives in moderate to good yields. In this way, three star‐like conjugated dendrimers with rigid macrocyclic cores 4k–m, which showed good photophysical properties, were also synthesized. The band gaps of 4k–m are 3.49, 3.49 and 3.45 eV, and the fluorescence quantum yields are 0.64, 0.78, 0.48 (2‐aminopyridine as a standard and excited at 310 nm), respectively. Electrochemical studies revealed their HOMO and LUMO energy levels. Our research disclosed that these CTV dendrimers could potentially be used as host materials in OLEDs.

Electron Acceptors Based on Functionalizable Cyclopenta[hi]aceanthrylenes and Dicyclopenta[de,mn]tetracenes

We report the synthesis and selective functionalization of two externally fused cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs) and demonstrate their electron accepting behavior. 2,7-Bis(trimethylsilyl)cyclopenta[hi]aceanthrylene (1) and 2,8-bis(trimethylsilyl)dicyclopenta[de,mn]tetracene (4) were prepared in a one-pot, palladium-catalyzed cross-coupling of (trimethylsilyl)acetylene and either 9,10-dibromoanthracene or 5,11-dibromotetracene, respectively. The trimethylsilyl groups were selectively converted into bromides via substitution with N-bromosuccinimide to create universal partners (2 and 6) for metal-catalyzed cross-coupling reactions. To demonstrate the utility of the halogenated CP-PAHs, we successfully employed a Sonogashira cross-coupling between the CP-PAHs and a phenylacetylene derivative. The resulting compounds (3 and 7) were found to be highly conjugated between the CP-PAH core and the substituents, as demonstrated by large bathochromic shifts in the absorption spectra as well as density functional theory calculations. Ethynylated CP-PAHs 3 and 7 were found to possess low optical bandgaps (1.52 and 1.51 eV, respectively) and displayed two reversible reductions. We further demonstrated the fullerene-like electron-accepting behavior of 3 through solution-phase fluorescence quenching of the prototypical electron donor, poly(3-hexylthiophene).

Self‐Assembly of Linear and Cyclic Siloxane‐Containing Mesogens: Investigation of Layered Structures in Bulk and Thin Films

Silicon-containing materials which possess the ability to form mesophases are promising systems for applications in the fields of electro-optical devices, nonlinear optics, and information storage media. In this work, the formation of supramolecular assemblies of a series of low molecular weight siloxane-containing mesogens is presented. Besides a novel synthesis route via Ru(II) -catalyzed hydrosilylation of phenyl acetylene derivatives, mesophase characterization by modern analysis techniques is performed. As linker groups, leading to bi- and tetramesogens, linear disiloxane and cyclic tetrasiloxane are utilized. In the resulting class of materials, high thermal stability, induced by the formation of layered smectic-type structures, is predominant. The smectic-type phases were found to be monotropic. Layer distances in the assemblies, as well as the phase transition temperatures, can be controlled by the substitution motif on the mesogens (number and length of alkyl chains). In spin-cast thin films, the layered domains are visualized by atomic force microscopy; furthermore, domain dimensions and electron densities are determined by grazing-incidence small-angle X-ray scattering.

Homobimetallic Ruthenium−Arene Complexes Bearing Vinylidene Ligands: Synthesis, Characterization, and Catalytic Application in Olefin Metathesis

Five new arylvinylidene complexes with substituents ranging from electron-donating to strongly withdrawing (p-OMe, p-Me, p-Cl, p-CF3, and m-(CF3)2) were isolated in high yields by reacting [(p-cymene)Ru(μ-Cl)3RuCl(η2-C2H4)(PCy3)] (3) with the corresponding phenylacetylene derivatives. The known phenylvinylidene complex [(p-cymene)Ru(μ-Cl)3RuCl(═C═CHPh)(PCy3)] (5) was also obtained from [RuCl2(p-cymene)]2, tricyclohexylphosphine, and phenylacetylene under microwave irradiation. The influence of the remote aryl substituents on structural features was investigated by IR, NMR, and XRD spectroscopies. A very good linear relationship was observed between the chemical shift of the vinylidene α-carbon atom and the Hammett σ-constants of the aryl group substituents. The catalytic activity of the six homobimetallic complexes was probed in various types of olefin metathesis reactions. Unsubstituted phenylvinylidene compound 5 served as a lead structure for these experiments. Its reaction with norbornene afforded hig...