Sonogashira-Hagihara Coupling Reaction Research Articles

Compressible and monolithic microporous polymer sponges prepared via one-pot synthesis.

Compressible and monolithic microporous polymers (MPs) are reported. MPs were prepared as monoliths via a Sonogashira–Hagihara coupling reaction of 1,3,5-triethynylbenzene (TEB) with the bis(bromothiophene) monomer (PBT-Br). The polymers were reversibly compressible, and were easily cut into any form using a knife. Microscopy studies on the MPs revealed that the polymers had tubular microstructures, resembling those often found in marine sponges. Under compression, elastic buckling of the tube bundles was observed using an optical microscope. MP-0.8, which was synthesized using a 0.8:1 molar ratio of PBT-Br to TEB, showed microporosity with a BET surface area as high as 463 m2g–1. The polymer was very hydrophobic, with a water contact angle of 145° and absorbed 7–17 times its own weight of organic liquids. The absorbates were released by simple compression, allowing recyclable use of the polymer. MPs are potential precursors of structured carbon materials; for example, a partially graphitic material was obtained by pyrolysis of MP-0.8, which showed a similar tubular structure to that of MP-0.8.

Highly Efficient Enrichment of Volatile Iodine by Charged Porous Aromatic Frameworks with Three Sorption Sites

AbstractThe targeted synthesis of a series of novel charged porous aromatic frameworks (PAFs) is reported. The compounds PAF‐23, PAF‐24, and PAF‐25 are built up by a tetrahedral building unit, lithium tetrakis(4‐iodophenyl)borate (LTIPB), and different alkyne monomers as linkers by a Sonogashira–Hagihara coupling reaction. They possess excellent adsorption properties to organic molecules owing to their “breathing” dynamic frameworks. As these PAF materials assemble three effective sorption sites, namely the ion bond, phenyl ring, and triple bond together, they exhibit high affinity and capacity for iodine molecules. To the best of our knowledge, these PAF materials give the highest adsorption values among all porous materials (zeolites, metal–organic frameworks, and porous organic frameworks) reported to date.

Highly Efficient Enrichment of Volatile Iodine by Charged Porous Aromatic Frameworks with Three Sorption Sites.

The targeted synthesis of a series of novel charged porous aromatic frameworks (PAFs) is reported. The compounds PAF-23, PAF-24, and PAF-25 are built up by a tetrahedral building unit, lithium tetrakis(4-iodophenyl)borate (LTIPB), and different alkyne monomers as linkers by a Sonogashira-Hagihara coupling reaction. They possess excellent adsorption properties to organic molecules owing to their "breathing" dynamic frameworks. As these PAF materials assemble three effective sorption sites, namely the ion bond, phenyl ring, and triple bond together, they exhibit high affinity and capacity for iodine molecules. To the best of our knowledge, these PAF materials give the highest adsorption values among all porous materials (zeolites, metal-organic frameworks, and porous organic frameworks) reported to date.

Water-soluble benzoselenadiazole-based conjugated polymer fluorescent sensor with high selectivity for ferric ions and mercury ions and possible applications as integrated molecular logic gates

A conjugated polymer P-1 based on benzoselenadiazole was synthesized by the polymerization of 1,4-bis[3′-(N,N-diethylamino)-1′-oxapropyl]-2,5-diiodobenzene (M-1) and 4,7-diethynylbenzoselenadiazole (M-2) via Pd-catalyzed Sonogashira–Hagihara coupling reaction. The water-soluble conjugated polyelectrolyte P-2 was obtained by the reaction of P-1 with ethyl bromide. The responsive optical properties of P-1 and P-2 on various metal ions were investigated by fluorescence spectroscopy in real-time detection. P-1 showed highly sensitive and selective detection of Fe3+ by ‘turn-on’ fluorescence enhancement in DMSO/H2O. P-2 exhibited outstanding sense of Hg2+ using BSe as receptor by ‘turn-off’ fluorescence quench type and Fe3+ using unionized triethylamino group as receptor by ‘turn-on’ fluorescence enhancement type in MeOH/H2O, respectively. Additionally, the addition of EDTA to the P-2–metal complexes could result in the fluorescence recovery of the P-2 solution. Fluorescence spectral responses as output signals and two independent molecular input signals based on P-2 could be used to demonstrate important logic operation like INHIBIT and IMPLICATION gates.

Tandem Catalytic C(sp3)H Amination/Sila‐Sonogashira–Hagihara Coupling Reactions with Iodine Reagents

AbstractA new tandem CN and CC bond‐forming reaction has been achieved through RhII/Pd0 catalysis. The sequence first involves an iodine(III) oxidant, then the in situ generated iodine(I) by‐product is used as a coupling partner. The overall process demonstrates the synthetic value of iodoarenes produced in trivalent iodine reagent mediated oxidations.

Targeted synthesis of porous aromatic frameworks with stimuli-responsive adsorption properties

Two porous aromatic frameworks, PAF-36 and PAF-37, containing azo moieties, were synthesized via Sonogashira–Hagihara coupling reactions. Gas sorption measurements indicated that reversible stimuli-responsive adsorption properties were triggered by ultraviolet (UV) irradiation and heat treatment, because of the presence of azo functional groups. The initial Brunauer–Emmett–Teller (BET) surface areas of PAF-36 and PAF-37 were 325 and 443 m2 g−1, respectively. After UV irradiation, the BET surface areas increased during the trans - cis isomerization process, and the micropore sizes, around 6 and 8 A, also increased. In addition, the CO2 adsorption capacities increased slightly because of trans - cis conversion of azo groups. It is worth mentioning that the CO2 uptakes of the polymers were almost constant during multiple cycles of alternating external stimuli, displaying high switchability of the trans - cis isomerization.

Diastereoselective cyclization of an aminobenzoic acid derivative and chiroptical properties of triple-stranded helical bis(phenylethynyl)benzene.

The diastereoselective cyclization of 2,5-dibromo-4-hexylaminobenzoic acid was achieved by the microwave-assisted condensation using SiCl4. Moreover, the triple-stranded helical structure of bis(phenylethynyl)benzene units embedded in the cyclic tri(benzamide) scaffold was obtained by a Sonogashira-Hagihara coupling reaction. Two optically active enantiomers that do not racemize even at the elevated temperature were separated by chiral HPLC. The chiral helical topology was revealed by the spectroscopic data and theoretical calculation.

Conjugated Microporous Polymers Based on Tetraphenylethylene for Gas Adsorption

Conjugated microporous polymers (CMPs) are attracting increasing attention due to their potential applications in areas such as gas adsorption, separation, heterogeneous catalysis and photoelectron. A series of CMPs based on tetra- phenylethylene has been synthesized via Pd-catalyzed Sonogashira-Hagihara coupling reaction. During polymerization, all of the polymer networks precipitated from solution as yellow powders that are totally insoluble in common organic solvents tested because of their highly crosslinked structures. Thermogravimetric analysis indicated that all of the polymer networks are thermally stable up to 400 in nitrogen atmosphere. Th ℃ e high physicochemical and thermal stability could be attributed to the rigid nature of these aromatic polymers, composed solely of strong carbon-carbon and carbon-hydrogen bonds. The absence of the C≡H stretching peaked at around 3280 cm -1 and the C—Br stretching peaked at around 500 cm -1 in the FT-IR spectra for the polymer networks demonstrated that most of the ethynyl and bromine functional groups in the starting materials have been consumed by coupling reaction. Powder X-ray diffraction measurements revealed that all of the polymer networks are amorphous in nature. It was found that the homo-coupled polymer network of TPE-CMP1 from 1,1,2,2-tetrakis(4-ethynylphenyl)ethene shows the highest Brunauer-Emmet-Teller specific surface area up to 1096 m 2 •g -1

M(II) Schiff base complexes (M = zinc, manganese, cadmium, cobalt, copper, nickel, iron, and palladium) supported on superparamagnetic Fe3O4@SiO2 nanoparticles: synthesis, characterization and catalytic activity for Sonogashira–Hagihara coupling reactions

A series of magnetically separable catalysts consisting of Schiff base complexes of metal ions (Zn, Mn, Cd, Co, Cu, Ni, Fe and Pd) supported on superparamagnetic Fe3O4@SiO2 nanoparticles has been prepared. The structural features of the catalysts were characterized by XRD, FTIR, TEM, FE-SEM, DLS, VSM, UV–Vis, TGA, AFM and N2 adsorption–desorption. Some of the Fe3O4@SiO2/Schiff base complexes were found to be efficient catalysts for the Cu-free and the phosphine free Sonogashira–Hagihara coupling reaction of aryl halides and phenylacetylene. The catalysts are superparamagnetic, and thus could be easily separated by the utilization of an external magnetic field, and could be reused for six cycles without significant loss of activity.

ChemInform Abstract: Synthesis and Characterization of Schiff Base Complex of Pd(II) Supported on Superparamagnetic Fe3O4@SiO2 Nanoparticles and Its Application as an Efficient Copper‐ and Phosphine Ligand‐Free Recyclable Catalyst for Sonogashira—Hagihara Coupling Reactions.

AbstractThe heterogeneous catalyst is easily removed by means of an external magnet and reused six times without significant loss of activity.

Palladium nanoparticles supported on agarose-functionalized magnetic nanoparticles of Fe3O4 as a recyclable catalyst for C–C bond formation via Suzuki–Miyaura, Heck–Mizoroki and Sonogashira–Hagihara coupling reactions

Palladium nanoparticles supported on agarose functionalized Fe3O4 catalyzed C–C bond formation reactions.

Robust tri(4-ethynylphenyl)amine-based porous aromatic frameworks for carbon dioxide capture

We report here the synthesis and carbon dioxide capture of a series of porous aromatic framework (PAF) materials assembled using tri(4-ethynylphenyl)amine and various aryl halides via Sonogashira–Hagihara coupling reactions. These PAF materials show moderate surface areas ranging from 370 m2 g−1 to 953 m2 g−1. The functional groups, such as –COOH, –NH2 and –OH, are incorporated into the backbone of the PAF materials. The isosteric heats of CO2 and CO2/N2 selectivities for these PAFs are calculated based on the CO2 and N2 adsorption isotherms measured at 273 and 298 K. It is found that the –NH2 functionalized network shows the highest isosteric heat of CO2 and CO2/N2 selectivity. In addition, the –COOH functionalized network displays the highest CO2 uptake in terms of per unit areas (4.37 μmol m−2, 273 K). The results indicate the incorporation of functional groups is effective for synthesizing CO2-philic PAF networks with enhanced interaction with CO2 molecules.

Synthesis and characterization of Schiff base complex of Pd(II) supported on superparamagnetic Fe3O4@SiO2 nanoparticles and its application as an efficient copper- and phosphine ligand-free recyclable catalyst for Sonogashira–Hagihara coupling reactions

Superparamagnetic nanoparticles functionalized with Schiff base complex of Pd (II) were simply synthesized by a two-step method. The catalyst was characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS),vibrating sample magnetometry (VSM), Fourier transform infrared (FT-IR), and N2 adsorption–desorption isotherm analysis. Also, its Pd content was determined by Inductively Coupled Plasma (ICP) analyzer. The immobilized palladium complex was used as an efficient catalyst for copper- and phosphine ligand-free Sonogashira reaction of aryl halides with phenylacetylene. This catalyst shows notable advantages such as simplicity of operation, excellent yields, short reaction times, heterogeneous nature, easy magnetically work up and recyclability.

Synthesis and characterization of Fe3O4@SiO2–polymer-imid–Pd magnetic porous nanospheres and their application as a novel recyclable catalyst for Sonogashira–Hagihara coupling reactions

We demonstrate herein the modification of magnetic nanoparticles and their use as a magnetic nanocatalyst in direct coupling reactions of aryl halides with terminal alkynes. Magnetite particles were prepared by simple co-precipitation method in aqueous medium, and then Fe3O4@ SiO2 nanosphere was synthesized by using nano-Fe3O4 as the core, TEOS as the silica source and PVA as the surfactant. Fe3O4@SiO2 was coated with polymeric N-heterocyclic carbene/Pd. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, dynamic light scattering, thermogravimetric analysis, vibration sample magnetometer and N2 adsorption–desorption isotherm analysis. Poly (N-vinyl imidazole) functionalized Fe3O4@SiO2 nanoparticle was found to be an efficient nanocatalyst in Sonogashira–Hagihara cross-coupling reactions. The nanocatalyst can be easily recovered by a magnetic field and reused for six runs without appreciable loss of its catalytic activity.

Construction and sorption properties of pyrene-based porous aromatic frameworks

We report here pyrene-based fluorescent porous aromatic frameworks (PAF-19 and PAF-20), which are constructed by a quadrilateral building unit 1,3,6,8-tetrabromopyrene (TBrPy) with linkers 1,4-diethynylbenzene and 1,3,5-triethynylbenzene via Sonogashira–Hagihara coupling reaction, respectively. TG analysis shows that PAF-19 and PAF-20 are thermally stable up to 350°C in air condition. Both materials also exhibit high chemical stability and cannot dissolve or decompose in any common organic solvents. N2 sorption results reveal that the BET surface areas of PAF-19 and PAF-20 are 250m2g−1 and 702 m2g−1, respectively. They also display relatively high sorption abilities for hydrogen and carbon dioxide. H2O sorption measurements demonstrate that the skeletons of PAF-19 and PAF-20 are highly hydrophobic. Interestingly, PAF-19 and PAF-20 exhibit excellent sorption abilities to organic chemical pollutants at the saturated vapor pressure and room temperature. PAF-20 can adsorb large amounts of methanol and benzene, with values of 609mgg−1 and 1038mgg−1, respectively. The good performances of PAF-19 and PAF-20 with high sorption selectivity promise their potential application for eliminating environmental pollutants in presence of H2O.

Synthesis and tuning of optical properties of conjugated polymers involving benzo[h]quinoline-based neutral pentacoordinate organosilicon complexes in the main chain

We present the synthesis and optical properties of a series of alternating polymers containing pentacoordinate silicon complexes in the main chain. By employing the benzo[h]quinoline ligand, the pentacoordinate silicon complexes were obtained. The polymers were prepared via the Sonogashira–Hagihara coupling reaction. From the series of measurements for optical properties of the synthesized polymers, new absorption bands and bathochromic shifts in emission spectra were observed. These data suggest that intramolecular charge transfer could occur after the excitation because of the elongation of π-conjugation via the polymer main chains. The modulation of the optical properties of the conjugated polymers involving the pentacoordinate silicon was accomplished.

ChemInform Abstract: Copper‐ and Amine‐Free Sonogashira—Hagihara Coupling Reaction Catalyzed by Pd(0) Nanoparticles Supported on Modified Crosslinked Polyacrylamide.

AbstractThe method requires tetrabutylammonium bromide which acts as base and phase‐transfer catalyst.

Palladium nano-particles supported on agarose as efficient catalyst and bioorganic ligand for C[sbnd]C bond formation via solventless Mizoroki–Heck reaction and Sonogashira–Hagihara reaction in polyethylene glycol (PEG 400)

In this study, abundant naturally occurring agarose has been used as a support and ligand for palladium nanoparticles. In the presence of this catalytic system, Mizoroki–Heck and Sonogashira–Hagihara coupling reactions were performed successfully. The catalyst exhibits high activity in Mizoroki–Heck reaction under phosphane and solvent-free conditions for the reaction of iodo- and bromoarenes with butyl acrylate and styrene. This catalytic system also showed high catalytic activity for Sonogashira–Hagihara coupling reaction of various aryl halides (I, Br, Cl) under copper and ligand-free conditions in polyethylene glycol (PEG 400) as an ecofriendly and non-poisonous media. The catalyst can be separated from the reaction mixture and reused for the similar batches of the reaction. High efficiency of the catalyst along with its recycling ability and the rather low Pd-loading which are demonstrated in both Mizoroki–Heck and Sonogashira–Hagihara reactions are the merits of the presented catalyst system.

Sonogashira–Hagihara Coupling towards Diaryl Alkynes Catalyzed by FeCl3⋅6 H2O/Cationic 2,2'‐Bipyridyl

AbstractEfficient and environmentally benign one‐pot Sonogashira–Hagihara coupling of aryl iodides with 4‐aryl‐2‐methylbut‐3‐yn‐2‐ols catalyzed by an FeCl3⋅6 H2O/cationic 2,2'‐bipyridyl system in water under air in the presence of zinc powder reductant was performed. Various aryl iodides and 4‐aryl‐2‐methylbut‐3‐yn‐2‐ols were used as reactants, which afforded moderate to high yields of cross‐coupled products. Although alkyl‐substituted 2‐methylbut‐3‐yn‐2‐ol could not be coupled with aryl iodides, the use of alkyl terminal alkynes under similar conditions provided the corresponding products in moderate yields. This reaction protocol was also used to synthesize both symmetric and asymmetric 1,4‐diarylbuta‐1,3‐diynes. This one‐pot iron‐catalyzed Sonogashira–Hagihara coupling reaction progressed without the use of an organic solvent, a copper cocatalyst, or an inert atmosphere, rendering it an environmentally friendly method with potential for practical applications.

Synthesis of benzo[h]quinoline-based neutral pentacoordinate organosilicon complexes

Reactions of 10-benzo[h]quinolyllithium with a series of organosilanes led to the formation of neutral pentacoordinate complexes. The diethynyl-substituted complex was able to be converted to di(arylethynyl)-substituted ones by the Sonogashira-Hagihara coupling reaction. Electronegative substituents shortened N-Si distances and enhanced fluorescence intensity from the complexes.