Showing papers in "Applied Organometallic Chemistry in 2009"
TL;DR: In this paper, widely accepted methods of hydrotalcite preparation such as co-precipitation, urea hydrolysis, hydrothermal, sol- gel, microwave irradiation, steam activation and solvothermal have been selected and reviewed.
Abstract: In this paper, widely accepted methods of hydrotalcite preparation such as co-precipitation, urea hydrolysis, hydrothermal, sol – gel, microwave irradiation, steam activation and solvothermal have been selected and reviewed. Our review indicates that the nature of the divalent cations, the synthesis method, the calcination temperature and the nature of the interlayer species are determinant factors in shaping the surface properties of the layered double hydoxides. The basic strength of the surface base site and structural changes produced in the mixed oxides can be adjusted conveniently by varying the Al content during the synthesis. The combination of sol – gel with microwave irradiation during the gelling and crystallization steps has also been found to increase the surface area of the hydrotalcite-like compound. Copyright c � 2009 John Wiley & Sons, Ltd.
169 citations
TL;DR: The chemistry of simple acyclic aminophosphines (synthesis, characterization, reactivity and applications) is covered and particular focus is given to their ability to form chalcogenides along with their role played as ligands in coordination chemistry and as synthons in inorganic heterocyclic chemistry as mentioned in this paper.
Abstract: In recent years, research in organophosphorus chemistry has mainly focused in designing newer and better phosphorus ligands for synthesizing novel metal complexes with improved catalytic activities. Aminophosphines [tricoordinate phosphorus(III)–nitrogen systems] are considered as versatile compounds owing to the presence of nitrogen centres which, in principle, can influence additional reactivity features. They are quite sensitive to air and moisture due to the presence of polar PN bond(s). In spite of this, research in aminophosphine chemistry is gaining momentum day-by-day and this is due mainly to one reason: their rich behaviour as ligands in metal complex chemistry and subsequently in catalysis. Their role as synthons in inorganic heterocyclic chemistry has also helped produce new types of heterocycles. In this paper, the chemistry of simple acyclic aminophosphines (synthesis, characterization, reactivity and applications) is covered and particular focus is given to their ability to form chalcogenides along with their role played as ligands in coordination chemistry and as synthons in inorganic heterocyclic chemistry. Copyright © 2009 John Wiley & Sons, Ltd.
79 citations
TL;DR: In this paper, the selectivity of the process was established by NMR analysis and various Pt-based catalysts were screened to compare the activity and selectivity with Pt-nanoparticles catalysis.
Abstract: Selective hydrolytic oxidation of organohydrosilanes was achieved with water in the presence of Pt-nanoparticle catalyst. The selectivity of the process was established by NMR analysis. In addition, various Pt-based catalysts were screened to compare the activity and selectivity with Pt-nanoparticles catalysis. The method was equally applicable to hydrosilanes bearing unsaturated functional groups, which led to corresponding silanols under mild reaction conditions without formation of any side products. Pt-nanoparticle catalysis was studied in details using UV–vis, TEM and mercury poisoning experiments during the transformation. Copyright © 2009 John Wiley & Sons, Ltd.
74 citations
TL;DR: ZrOCl2·8H2O has been found to be an efficient catalyst for the synthesis of 1,8-dioxo-octahydroxanthenes from aldehydes and 5,5-dimethylcyclohexane-1,3-dione under solvent-free conditions.
Abstract: ZrOCl2·8H2O has been found to be an efficient catalyst for the synthesis of 1,8-dioxo-octahydroxanthenes from aldehydes and 5,5-dimethylcyclohexane-1,3-dione under solvent-free conditions. Copyright © 2009 John Wiley & Sons, Ltd.
70 citations
TL;DR: In this article, the use of a catalytic amount of piperidine as additive shows high catalytic activity for the oxidative homocoupling reactions of terminal alkynes in toluene at 60 °C in air to afford 1,3-diynes in high yields.
Abstract: CuCl with the use of a catalytic amount of piperidine as additive shows high catalytic activity for the oxidative homocoupling reactions of terminal alkynes in toluene at 60 °C in air to afford 1,3-diynes in high yields. Copyright © 2009 John Wiley & Sons, Ltd.
65 citations
TL;DR: The antitumor activities of ferrocenylmethyl thymine against solid tumor models, carcinoma 755 (Ca755) and Lewis lung carcinoma (LLC) were studied in vivo and therapeutic synergism of antitumors activity against LLC was demonstrated in the case of combined application of compound 1 with anticancer drug cyclophosphamide.
Abstract: Ferrocenylalkyl nucleobases (1–14) were prepared via the reaction of the α-(hydroxy)alkyl ferrocenes FcCHR(OH) (Fc = ferrocenyl; R = H, Me, Et, Ph) with thymine, cytosine, iodo-cytosine and adenine in DMSO at 100 °C, yields being 50–80%. The antitumor activities of ferrocenylmethyl thymine (1) against solid tumor models, carcinoma 755 (Ca755) and Lewis lung carcinoma (LLC) were studied in vivo. Therapeutic synergism of antitumor activity against LLC was demonstrated in the case of combined application of compound 1 with anticancer drug cyclophosphamide. Copyright © 2009 John Wiley & Sons, Ltd.
61 citations
TL;DR: Cationic diimine Ru(II) complexes were synthesized and tested as catalysts for the formation of cyclic organic carbonates from CO2 and liquid epoxides (propylene oxide, epichlorohydrine, 1,2-epoxybutane and styrene oxide) which served as both reactant and solvent as discussed by the authors.
Abstract: Cationic diimine Ru(II) complexes were synthesized and tested as catalysts for the formation of cyclic organic carbonates from CO2 and liquid epoxides (propylene oxide, epichlorohydrine, 1,2-epoxybutane and styrene oxide) which served as both reactant and solvent. The reaction rates not only depended on the type of ligand, but also on reaction conditions such as temperature, pressure, base, the epoxide substrates and the use of an additional solvent. Reaction rates in terms of turnover frequencies up to 4050 molproduct molcat.−1 h−1 at 99% selectivity were achieved by optimizing the diimine ligand as well as the reaction temperature and CO2 pressure. Consistent with CV measurements, the electron donating group on the p-position of the aryl ring accelerated the reaction rate. Copyright © 2008 John Wiley & Sons, Ltd.
57 citations
TL;DR: The PVP-stabilized palladium(0) nanoclusters were used in Heck and Suzuki coupling reactions of arylbromides with styrene and phenylboronic acid.
Abstract: Herein we report a new method for the synthesis and characterization of PVP-stabilized palladium(0) nanoclusters and their enhanced catalytic activity in Suzuki coupling and Heck reactions of aryl bromides with phenylboronic acid and styrene, respectively, under mild conditions. The PVP-stabilized palladium(0) nanoclusters with a particle size of 4.5 ± 1. 1n m were prepared using a new method: refluxing a mixture of potassium tetrachloropalladate(II) and PVP in methanol at 80 ◦ Cf or 1 h followed by reduction with sodium borohydride. Palladium(0) nanoclusters prepared in this way were stable in solution for weeks, could be isolated as solid materials and were characterized by TEM, XPS, UV – vis, and XRD techniques. The PVPstabilized palladium(0) nanoclusters were active catalysts in Heck and Suzuki coupling reactions of arylbromides with styrene and phenylboronic acid affording stilbenes and biphenyls, respectively, in high yield. Recycling experiments showed that PVP-stabilized palladium(0) nanoclusters could be used five times with essentially no loss in activity in the Heck and Suzuki coupling reactions. Copyright c � 2009 John Wiley & Sons, Ltd.
49 citations
TL;DR: Tetrakis[heptadecafluorononyl] substituted phthalocyanine complexes were prepared by template synthesis from 4-hexadecafeluoronyloxy)phthalonitrile with Co(CH3COO)·2H2O or PdCl2 in 2-N, N-dimethylaminoethanol as mentioned in this paper.
Abstract: Tetrakis[heptadecafluorononyl] substituted phthalocyanine complexes were prepared by template synthesis from 4-(heptadecafluorononyloxy)phthalonitrile with Co(CH3COO)·2H2O or PdCl2 in 2-N, N-dimethylaminoethanol. The corresponding phthalonitrile was obtained from heptadecafluorononan-1-ol and 4-nitrophthalonitrile with K2CO3 in DMF at 50 °C. The structures of the compounds were characterized by elemental analysis, FTIR, UV–vis and MALDI-TOF MS spectroscopic methods. Metallophthalocyanines are soluble in fluoroalkanes such as perfluoromethylcyclohexane (PFMCH). The complexes were tested as catalysts for benzyl alcohol oxidation with tert-butylhydroperoxide (TBHP) in an organic–fluorous biphasic system (n-hexane–PFMCH). The oxidation of benzyl alcohol was also tested with different oxidants, such as hydrogen peroxide, m-chloroperoxybenzoic acid, molecular oxygen and oxone in n-hexane–PFMCH. TBHP was found to be the best oxidant for benzyl alcohol oxidation since higher conversion and selectivity were observed when this oxidant was used. Copyright © 2008 John Wiley & Sons, Ltd.
48 citations
TL;DR: The Sonogashira cross-coupling of aryl iodides with terminal alkynes catalyzed by a simple and inexpensive catalyst system of CuI/PPh3 in water as the sole solvent has been reported in this article.
Abstract: The Sonogashira cross-coupling of aryl iodides with terminal alkynes catalyzed by a simple and inexpensive catalyst system of CuI/PPh3 in water as the sole solvent has been reported. In the presence of CuI/PPh3, with KOH used as a base, a number of aryl iodides were treated with alkynes to afford the corresponding products in moderate to excellent yields. Copyright © 2008 John Wiley & Sons, Ltd.
47 citations
TL;DR: In this paper, the aminocarbonylation and alkoxy carbonylation reactions of terminal alkynes took place smoothly and efficiently using a catalyst system Pd(OAc)2dppb•p-TsOH•CH3CN•CO under relatively mild experimental conditions.
Abstract: The aminocarbonylation and alkoxycarbonylation reactions of terminal alkynes took place smoothly and efficiently using a catalyst system Pd(OAc)2‐dppb‐p-TsOH‐CH3CN‐CO under relatively mild experimental conditions. The catalytic system was tested and optimized using two different nucleophiles: alcohols and amines. Phenylacetylene (1a) was considered as an alkyne along with diisobutylamine (2b1 )a nd methanol (2c1) as nucleophiles. The results showed significant differences in the conversion of 1a and in the selectivity towards the gem or trans unsaturated esters or amides with these nucleophiles. The effects ofthetypeof palladium catalysts,thetype ofligands,theamountof dppb andthesolventswerecarefullystudied.With diisobutylamine (2b1), excellent regioselectivity towards the 2-acrylamides (gem isomer, 3ab1) was almost always observed, while trans-α,β-unsaturated esters 4ac1 was the predominant product with methanol (2c1) as a nucleophile. This remarkable sensitivity in the selectivity of the reaction indicates two different possible mechanistic pathways for these carbonylation reactions. Copyright c � 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, the DNA-binding properties of the three complexes were investigated by absorption, emission, melting temperature and viscosity measurements, which indicated that all three complexes can intercalate into DNA base pairs.
Abstract: Polypyridyl ligand 9a,13a-dihydro-4,5,9,14-tetraaza-benzo[b]triphenylene-11-yl)-phenyl-methanone (BDPPZ) and its complexes [Ru(bpy)2BDPPZ]2+, [Ru(dmb)2BDPPZ]2+ and [Ru(phen)2BDPPZ]2+ (where bpy = 2,2′-bipyridine, dmb = 4,4′-dimethyl-2,2′-bipyridine, phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, IR, UV–vis, 1H-NMR, 13C-NMR and mass spectra. The DNA-binding properties of the complexes were investigated by absorption, emission, melting temperature and viscosity measurements. Experimental results indicate that the three complexes can intercalate into DNA base pairs. Photo activated cleavage of pBR-322 DNA by the three complexes was also studied. Further, all three Ru(II) complexes synthesized were screened for their antimicrobial activity. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In vitro study on A549 human lung adenocarcinoma cells revealed that the synthesized boronated conjugates are able to penetrate and accumulate in cancer cells, but their intracellular concentration is not sufficient for effective photodynamic and bor on neutron capture therapy of cancer.
Abstract: Conjugates of chlorin e6 with closo-dodecaborate and cobalt bis(dicarbollide) anions were synthesized for the first time in high yields using the advanced ‘click’ methodology. In vitro study on A549 human lung adenocarcinoma cells revealed that the synthesized boronated conjugates are able to penetrate and accumulate in cancer cells, but their intracellular concentration is not sufficient for effective photodynamic and boron neutron capture therapy of cancer. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, a number of new N-heterocyclic carbene (NHC) ligands were synthesized via a multicomponent reaction, wherein an aldehyde or ketone, a primary amine and an α-acidic isocyanide were reacted, giving the corresponding 2H-2-imidazolines.
Abstract: A number of new N-heterocyclic carbene (NHC) ligands were synthesized via a multicomponent reaction, wherein an aldehyde or ketone, a primary amine and an α-acidic isocyanide were reacted, giving the corresponding 2H-2-imidazolines. These were easily alkylated with an alkyl halide at position N-3, yielding the final NHC precursors, that were then complexed with Ru in situ. The resulting complexes are shown to be active and selective catalysts for the transfer hydrogenation of furfural to furfurol, using isopropanol as the hydrogen source. Importantly, the carbene ligand remains coordinated to the ruthenium center throughout the reaction.
TL;DR: Sulfonamide-derived compounds and their first row d-transition metal chelates [cobalt(II), copper(II, nickel(II) and zinc(II)] have been synthesized and characterized as discussed by the authors, and the nature of bonding and structure of all the synthesized compounds have been proposed from magnetic susceptibility and conductivity measurements, IR, 1H and 13C NMR, electron spectra, mass spectrometry and CHN analysis data.
Abstract: Sulfonamide-derived compounds and their first row d-transition metal chelates [cobalt(II), copper(II), nickel(II) and zinc(II)] have been synthesized and characterized. The nature of bonding and structure of all the synthesized compounds have been proposed from magnetic susceptibility and conductivity measurements, IR, 1H and 13C NMR, electron spectra, mass spectrometry and CHN analysis data. The structure of ligand, 4-{[(E)-(5-chloro-2-hydroxyphenyl) methylidene] amino}-N-(4,6-dimethyl pyrimidin-2-yl) benzene sulfonamide has also been determined by X-ray diffraction method. An octahedral geometry has been suggested for all the complexes. The ligands and metal complexes have been screened for their in vitro antibacterial, antifungal and cytotoxic activity. The results of these studies revealed that all compounds showed moderate to significant antibacterial activity against one or more bacterial strains and good antifungal activity against various fungal strains. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this paper, the authors used hexamethyldisilazane (HMDS) to catalyze trimethylsilylation of primary, secondary and tertiary alcohols as well as phenols.
Abstract: In this paper, rapid and highly efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) in the presence of catalytic amounts of high-valent [SnIV(TPP)(OTf)2] is reported. This catalytic system catalyzes trimethylsilylation of primary, secondary and tertiary alcohols as well as phenols, and the corresponding TMS-ethers were obtained in high yields and short reaction times at room temperature. It is noteworthy that this method can be used for chemoselective silylation of primary alcohols in the presence of secondary and tertiary alcohols and phenols. The catalyst was reused several times without loss of its catalytic activity. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, NMR spectroscopy and elemental analyses were performed for the ring-opening polymerization of e-caprolactone, and the structures of complexes 3, 5c and 6 were also characterized by single-crystal X-ray diffraction techniques.
Abstract: Reaction between 2-(1H-pyrrol-1-yl)benzenamine and 2-hydroxybenzaldehyde or 3,5-di-tert-butyl-2-hydroxybenzaldehyde afforded 2-(4,5-dihydropyrrolo[1,2-a]quinoxalin-4-yl)phenol (HOL1NH, 1a) or 2,4-di-tert-butyl-6-(4,5-dihydropyrrolo[1,2-a]quinoxalin-4-yl)phenol (HOL2NH, 1b). Both 1a and 1b can be converted to 2-(H-pyrrolo[1,2-a]quinoxalin-4-yl)phenol (HOL3N, 2a) and 2,4-di-tert-butyl-6-(H-pyrrolo[1,2-a]quinoxalin-4-yl)phenol (HOL4N, 2b), respectively, by heating 1a and 1b in toluene. Treatment of 1b with an equivalent of AlEt3 afforded [Al(Et2)(OL2NH)] (3). Reaction of 1b with two equivalents of AlR3 (R = Me, Et) gave dinuclear aluminum complexes [(AlR2)2(OL2N)] (R = Me, 4a; R = Et, 4b). Refluxing the toluene solution of 4a and 4b, respectively, generated [Al(R2)(OL4N)] (R = Me, 5a; R = Et, 5b). Complexes 5a and 5b were also obtained either by refluxing a mixture of 1b and two equivalents of AlR3 (R = Me, Et) in toluene or by treatment of 2b with an equivalent of AlR3 (R = Me, Et). Reaction of 2a with an equivalent of AlMe3 afforded [Al(Me2)(OL3N)] (5c). Treatment of 1b with an equivalent of ZnEt2 at room temperature gave [Zn(Et)(OL2NH)] (6), while reaction of 1b with 0.5 equivalent of ZnEt2 at 40 °C afforded [Zn(OL2NH)2] (7). Reaction of 1b with two equivalents of ZnEt2 from room temperature to 60 °C yielded [Zn(Et)(OL4N)] (8). Compound 8 was also obtained either by reaction between 6 and an equivalent of ZnEt2 from room temperature to 60 °C or by treatment of 2b with an equivalent of ZnEt2 at room temperature. Reaction of 2b with 0.5 equivalent of ZnEt2 at room temperature gave [Zn(OL4N)2] (9), which was also formed by heating the toluene solution of 6. All novel compounds were characterized by NMR spectroscopy and elemental analyses. The structures of complexes 3, 5c and 6 were additionally characterized by single-crystal X-ray diffraction techniques. The catalysis of complexes 3, 4a, 5a–c, 6 and 8 toward the ring-opening polymerization of e-caprolactone was evaluated. Copyright © 2008 John Wiley & Sons, Ltd.
TL;DR: In this paper, the synthesis and structural features of tri-and diorganotin(IV) complexes of the general formulae, RnSn(L)m [n = 3, m = 1, R = Me, n-Bu, nOct and Ph; HL = Schiff base derived from the condensation of 2-aminomethylbenzimidazole and salicylaldehyde (abbreviated as HL or Hsal-ambmz)].
Abstract: This report deals with the synthesis and structural features of tri- and diorganotin(IV) complexes of the general formulae, RnSn(L)m [n = 3, m = 1, R = Me, n-Bu and Ph; n = 2, m = 2, R = Me, n-Bu, n-Oct and Ph; HL = Schiff base derived from the condensation of 2-aminomethylbenzimidazole (ambmz) and salicylaldehyde (abbreviated as HL or Hsal-ambmz)]. The newly synthesized complexes were characterized by elemental analysis, molar conductance, electronic, infrared, far-infrared, 1H NMR, 13C NMR, 119Sn NMR and 119Sn Mossbauer spectral studies. Thermal studies of all of the synthesized complexes were also carried out using thermogravimetry–differential thermal analysis-derivative thermogravimetric (TG-DTA-DTG) techniques. The residues thus obtained were characterized by infrared and powder X-ray diffraction analysis. The bioassay results of anti-inflammatory activity (using the carrageenan-induced paw edema bioassay in rats) and acute toxicity (LD50) of the synthesized derivatives indicated that diorganotin(IV) derivatives (19.75–22.23% inhibition) show better activity as compared with triorganotin(IV) derivatives (10.32–17.86% inhibition). Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this paper, the reaction of 2-(aminomethyl)aniline with 2 equivalents of PPh2Cl in the presence of Et3N, proceeds in CH2Cl2 to give N,N′-bis(diphenylphosphino)-2-(amino-niline 1 in good yield.
Abstract: The reaction of 2-(aminomethyl)aniline with 2 equivalents of PPh2Cl in the presence of Et3N, proceeds in CH2Cl2 to give N,N′-bis(diphenylphosphino)-2-(aminomethyl)aniline 1 in good yield. Oxidation of 1 with aqueous H2O2, elemental sulfur or gray selenium gave the corresponding oxide, sulfide and selenide dichalcogenides [Ph2P(E)NHC6H4CH2NHP(E)Ph2] (E: O, 2a; S, 2b; Se, 2c), respectively. The reaction of [Ph2PNHC6H4CH2NHPPh2] with PdCl2(cod), PtCl2(cod) and [Cu(MeCN)4]PF6 gave the corresponding chelate complexes, PdCl21, PtCl21 and [Cu(1)2]PF6. The new compounds were fully characterized by NMR, IR spectroscopy and elemental analysis. The catalytic activity of the Pd(II) complex was tested in the Suzuki coupling and Heck reactions. The Pd(II) complex catalyzes the Suzuki coupling and Heck reaction, affording biphenyls and stilbenes respectively, in good yields. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, the synthesis of an air-stable series of Pd-0 complexes with dissymmetric bidentate N-heterocyclic carbene-amine ligands has been performed.
Abstract: The synthesis of an air-stable series of Pd-0 complexes with dissymmetric bidentate N-heterocyclic carbene-amine ligands has been performed. The key step is an unprecedented carbene transfer from Ag-1 to obtain electron-rich zero-valent palladium precatalysts. The coordination behavior of the ligands was determined with X-ray crystallography. Surprising results were obtained in the catalysis of transfer semi-hydrogenation, where the addition of base appeared not to be necessary to obtain the desired product stereoselectively.
TL;DR: In this article, the solid-state molecular structures of representative palladium and platinum complexes of bis(phosphine)amine, 2a and 2b, respectively, were determined using single crystal X-ray diffraction analysis.
Abstract: The reactions of thiophene-2-(N-diphenylphosphino)methylamine, Ph2PNHCH2-C4H3S, 1 and thiophene-2-[N,N-bis(diphenylphosphino)methylamine], (Ph2P)2NCH2-C4H3S, 2, with MCl2(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) or [Cu(CH3CN)4]PF6 yields the new complexes [M(Ph2PNHCH2-C4H3S)2Cl2], M = Pd 1a, Pt 1b, [Cu(Ph2PNHCH2-C4H3S)4]PF6, 1c, and [M(Ph2P)2NCH2-C4H3S)Cl2], M = Pd 2a, Pt 2b, {Cu[(Ph2P)2NCH2-C4H3S]2}PF6, 2c, respectively. The new compounds were isolated as analytically pure crystalline solids and characterized by 31P-, 13C-, 1H-NMR and IR spectroscopy and elemental analysis. Furthermore, the solid-state molecular structures of representative palladium and platinum complexes of bis(phosphine)amine, 2a and 2b, respectively, were determined using single crystal X-ray diffraction analysis. The palladium complexes were tested as potential catalysts in the Heck and Suzuki cross-coupling reactions. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, three-dimensional flower-like α-Fe2O3 nanostructures have been successfully synthesized by a simple surfactant-free environmental friendly solvolthermal process.
Abstract: Three-dimensional flower-like α-Fe2O3 nanostructures have been successfully synthesized by a simple surfactant-free environmental friendly solvolthermal process. The as-prepared products were investigated by X-ray powder diffraction, transmission electron microscopy, and field emission scanning electron microscopy. By adjusting the synthetic parameters, the shape of the α-Fe2O3 nanostructures can be controlled. The three-dimensional flower-like α-Fe2O3 nanostructures were found to be highly active as catalysts for phenol alkylation. The effects of various parameters, such as reaction temperature, reaction time and the amount of catalyst, were studied. The catalyst was stable and could be reused three times in normal atmosphere without suffering appreciable loss in catalytic activity. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this paper, the use of palladium catalysts derived from 1,1′-bis-diisopropylphosphino-ferrocene and a microwave heating source allows the coupling of a range of ortho-substituted aryl bromides to diphenylphphosphine derivatives to proceed in good yield in under 30 min.
Abstract: The use of palladium catalysts derived from 1,1′-bis-diisopropylphosphino-ferrocene and a microwave heating source allows the coupling of a range of ortho-substituted aryl bromides to diphenylphosphine derivatives to proceed in good yield in under 30 min. Optimization studies reveal that the combination of diphenylphosphine and DABCO is superior to more basic phosphide nucleophiles such as Ph2PK or Ph2PMgBr. High yields are only observed when moderately bulky electron rich diphosphines are used as ligands. The differences between PC coupling and other cross-coupling reactions are discussed in the light of the reactivity observed. Studies aimed at producing industrially important 1,2-bis-phosphino-benzene ligands are also described. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, a series of homo-, heterodinuclear and homotrinuclear copper(II) complexes containing a new Schiff base ligand and 1,10-phenanthroline were synthesized.
Abstract: A series of homo-, heterodinuclear and homotrinuclear copper(II) complexes containing a new Schiff base ligand and 1,10-phenanthroline were synthesized. Based on results of elemental analyses, FTIR, 1H- and 13C-NMR spectra, conductivity measurements and magnetic susceptibility measurements, the complexes had general compositions {[Cu(L)(H2O)M(phen)2](ClO4)2 [M = Cu(II), Mn(II), Co(II)]} and {[Cu3(L)2(H2O)2](ClO4)2}. The metal:L:phen ratio is 2:1:2 for the dinuclear copper(II) complexes and the metal:L ratio was 3:2 for the trinuclear copper(II) complex. The liquid–liquid extraction of various transition metal cations [Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II), Hg(II)] from the aqueous phase to the organic phase was carried out using the diimine–dioxime ligand. It was concluded that the ligand can effectively be used in solvent extraction of copper(II) from the aqueous phase to the organic phase. Furthermore, catalytic activitiy of the complexes for the disproportionation of hydrogen peroxide was also investigated in the presence of imidazole. Dinuclear copper(II)–manganese(II) complex has some similarity to manganese catalase in structure and activity. The interaction between these complexes and DNA has also been investigated by agarose gel electrophoresis; we found that the homo- and heterodinuclear copper complexes can cleave supercoiled pBR322 DNA to nicked and linear forms in the presence of H2O2. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this paper, a double-face role of chelating effect was proposed for the copper-mediated amination of aryl halides with ammonia based on a double face role.
Abstract: Direct amination of aryl iodides and bromides with ammonia under 1 atm pressure has been effected using in situ-generated hemilabile coordinated copper(I) species from copper(I) halides or copper metal in aqueous ethylene glycol, producing primary aromatic amines in good yields. Ammonia pressure and water were found to accelerate the copper-mediated reaction while strong chelating ligands showed a suppression effect. A rationale for the copper-mediated amination of aryl halides with ammonia is given based on a double-face role of chelating effect. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, an approach for the formation of mixed functional group silsesquioxane cages was proposed. But the approach was not suitable for the T8, T 10 and T 12 species, and all conditions tried, including changing the solvent to EtOH or toluene or at reflux (THF), did not yield the desired results.
Abstract: Insoluble mixtures of polyvinylsilsesquioxane, -(vinylSiO1.5)n- PVS, and polymethylsilsesquioxanes, -(MeSiO1.5)n -P MS, in THF at ambient when treated with catalytic amounts (1 – 5 mol%) of fluoride ion introduced astBu4 NF will depolymerize and dissolve. The resulting soluble species consist of [vinylx Me8−x (SiO1.5)]8 ,[ vinylx Me8−x (SiO1.5)]10 and [vinylx Me8−x (SiO1.5)]12 .R atios of 1 : 1 of PVS : PMS greatly favor formation of vinyl rich cages. Only at ratios of 1 : 5 are the proportions of vinyl : Me in the cages approximately equal. Of the T8 ,T 10 and T12 species produced, all conditions tried, including changing the solvent to EtOH or toluene or at reflux (THF), favor the formation of the larger cages sometimes completely excluding formation of the T8 materials. Efforts to isolate the cage compounds by removal of solvent regenerates polysilsesquioxanes, albeit those containing mixtures of Me and vinyl groups. Introduction of CaCl2 sufficient to form CaF2 prior to workup prevents repolymerization, allowing recovery of the mixed cage systems. The approach developed here provides a novel way to form mixed functional group silsesquioxane cages. The fact that T10 and T12 cage formation is favored appears to suggest that these cages are more stable than the traditionally produced T8 cages. Copyright c � 2009 John Wiley & Sons, Ltd.
TL;DR: In this paper, a chelated ferrocene-based planar chiral N-heterocyclic carbene-Rh(I) complex was synthesized by a simple method.
Abstract: A novel chelated ferrocene-based planar chiral N-heterocyclic carbene-Rh(I) complex was synthesized by a simple method. It was applied to the asymmetric transfer hydrogenation of prochiral ketones. Enantioselectivities of up to 67% ee were observed. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: Bis(imino)pyridine palladium(II) complexes 3 and 4 of type [PdCl(L)PF6] are found to be efficient catalysts for Suzuki-Miyaura reactions of aryl halides and arylsboronic acids as discussed by the authors.
Abstract: Bis(imino)pyridine palladium(II) complexes 3 and 4 of type [PdCl(L)PF6] are found to be efficient catalysts for Suzuki–Miyaura reactions of aryl halides and arylboronic acids. The reactions proceed smoothly to generate the corresponding biaryl compounds in moderate to excellent yields. The synthesis of various fluorinated biphenyl derivatives was successfully achieved by the complex 4 catalyzed the Suzuki–Miyaura reaction in the presence of surfactants bearing a long alkyl chain. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, a bis(imino)pyridine palladium(II) complexes were synthesized and complex 12 proved to be a highly efficient catalyst for the Suzuki cross-coupling reaction between aryl bromides and arylsboronic acids in air using water as solvent.
Abstract: Air-stable bis(imino)pyridine palladium(II) complexes were synthesized and complex 12 proved to be a highly efficient catalyst for the Suzuki cross-coupling reaction between aryl bromides and arylboronic acids in air using water as solvent. The coupling reaction proceeded smoothly under mild conditions to provide biaryls in excellent yields and Pd black was not observed. The recycling of the catalysts was also investigated, for up to three cycles, and complex 12 still exhibited good activity. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: In this article, the authors investigated the effect of the anionic ligands on the outcome of the reaction and found that the nature of the employed heterocycle, in particular its steric characteristics, strongly influenced the outcome.
Abstract: Chelating dicarbene complexes of palladium(II) and platinum(II) catalyse at room temperature with 1% catalyst loading the reaction of ethyl phenylpropiolate with aromatic heterocycles to yield synthetically useful intermediates for fine chemicals without the need to use prefunctionalized substrates. The reaction outcome was found to be strongly dependent on the nature of the anionic ligands at the metal complex. Addition of silver salts to replace halide ligands with more weakly coordinating anions improves the reaction yield and changes the product distributions: heterocyclealkyne 2:1 adducts are obtained together with the usual hydroarylation products, which potentially broadens the scope of the reaction. The nature of the employed heterocycle, in particular its steric characteristics, is also found to strongly influence the outcome of the reaction. Copyright © 2009 John Wiley & Sons, Ltd.