- Synthesis of Pyridylsulfonium Salts and Their Application in the Formation of Functionalized Bipyridines
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An S-selective arylation of pyridylsulfides with good functional group tolerance was developed. To demonstrate synthetic utility, the resulting pyridylsulfonium salts were used in a scalable transition-metal-free coupling protocol, yielding functionalized bipyridines with extensive functional group tolerance. This modular methodology permits selective introduction of functional groups from commercially available pyridyl halides, furnishing symmetrical and unsymmetrical 2,2′- A nd 2,3′-bipyridines. Iterative application of the methodology enabled the synthesis of a functionalized terpyridine with three different pyridine components.
- Duong, Vincent K.,Horan, Alexandra M.,McGarrigle, Eoghan M.
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p. 8451 - 8457
(2020/11/12)
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- Reductive couplings of 2-halopyridines without external ligand: Phosphine-free nickel-catalyzed synthesis of symmetrical and unsymmetrical 2,2'-bipyridines
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An unexpectedly facile synthetic approach for symmetrical and unsymmetrical 2,2'-bipyridines through the Ni-catalyzed reductive couplings of 2-halopyridines was developed. The couplings were efficiently catalyzed by 5 mol % of NiCl2.6H2O without the use of external ligands. A variety of 2,2'-bipyridines including caerulomycin F have been efficiently synthesized.
- Liao, Lian-Yan,Kong, Xing-Rui,Duan, Xin-Fang
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p. 777 - 782
(2014/04/03)
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- Dilithium tetrachlorocuprate(II) catalyzed oxidative homocoupling of functionalized grignard reagents
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An efficient procedure is described for the oxidative homocoupling of functionalized Grignard reagents using a catalytic amount of dilithium tetrachlorocuprate(II) (CuLi2Cl4) in the presence of pure oxygen gas. This method is applied successfully to a variety of aryl, heteroaryl, alkyl, alkenyl and alkynyl halides, which are converted into the corresponding homocoupled products in good to excellent yields. Georg Thieme Verlag Stuttgart · New York.
- Hua, Si-Kai,Hu, Qiu-Peng,Ren, Jiangmeng,Zeng, Bu-Bing
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p. 518 - 526
(2013/03/29)
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- Influence of the torsion angle in 3,3′-Dimethyl-2,2′-bipyridine on the intermediate valence of Yb in (C5Me5) 2Yb(3,3′-Me2-bipy)
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The synthesis and X-ray crystal structures of Cp*2Yb(3, 3′-Me2bipy) and [Cp*2Yb(3,3′-Me 2bipy)][Cp*2YbCl1.6I0.4] ·CH2Cl2 are described. In both complexes, the NCCN torsion angles are approximately 40. The temperature-independent value of n f of 0.17 shows that the valence of ytterbium in the neutral adduct is multiconfigurational, in reasonable agreement with a CASSCF calculation that yields a nf value of 0.27; that is, the two configurations in the wave function are f13(π*1)1 and f 14(π*1)0 in a ratio of 0.27:0.73, respectively, and the open-shell singlet lies 0.28 eV below the triplet state (nf accounts for f-hole occupancy; that is, nf = 1 when the configuration is f13 and nf = 0 when the configuration is f14). A correlation is outlined between the value of n f and the individual ytterbocene and bipyridine fragments such that, as the reduction potentials of the ytterbocene cation and the free x,x′-R2-bipy ligands approach each other, the value of n f and therefore the f13:f14 ratio reaches a maximum; conversely, the ratio is minimized as the disparity increases.
- Nocton, Gregory,Booth, Corwin H.,Maron, Laurent,Andersen, Richard A.
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p. 5305 - 5312
(2013/11/06)
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- Electrochemical coupling of mono and dihalopyridines catalyzed by nickel complex in undivided cell
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One step nickel-catalyzed electroreductive homocoupling among 2-bromopicolines and 2-bromopyridine has been investigated by our group in an undivided cell and using zinc or iron as sacrificial anode. In this work, it was developed mono and dihalopyridines coupling to obtain possible products from heterocoupling. A series of reactions were carried out in order to develop a synthetic method for the preparation of unsymmetrical 2,2′-bipyridines and 2,2′:6′,2″-terpyridines. Statistical yields (50%) were observed for 2-bromopyridines/2-bromo-6-methylpyridine heterocoupling. In a preliminary study devoted to terpyridines preparation, good results were obtained for 2,6-dihalopyridines homocoupling, affording 2,6-dichloro-2, 2′-bipyridine (46%) and 2,6-dibromo-2,2′-bipyridine (56%), at controlled reaction time. At major reaction time, it was observed that the direct electroreduction of the 2,6′-dihalo-2,2′-bipyridines intermediates and 2,6″-dihalo-2,2′:6′,2″-terpyridines products on the cathode surface. A reasonable isolated product yield of 6,6″-dimethyl-2,2′:6′,2″-terpyridine (10%) was only observed in the reaction between 2,6-dichloropyridine and 2-bromo-6- methylpyridine (1:2).
- Oliveira, Jadson L.,Silva, Maria J.,Florêncio, Tupolevck,Urgin, Karne,Sengmany, Stéphane,Léonel, Eric,Nédélec, Jean-Yves,Navarro, Marcelo
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experimental part
p. 2383 - 2390
(2012/04/17)
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- Catalytic homocoupling of aryl, alkenyl, and alkynyl halides with Ni(II)-complexes and zirconocene dichloride
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A new catalytic system (cat. (H)2Phen(Me)2· NiCl2 or (MeO)2Dipyr(H)2·NiCl 2, cat. Zr(cp)2Cl2, 2 equiv Mn, and 2 equiv LiCl) has been developed to facilitate the homocoupling of a wide range of aryl, alkenyl, and alkynyl halides.
- Peng, Jianbiao,Liu, Xiang,Kishi, Yoshito
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experimental part
p. 2172 - 2175
(2011/05/05)
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- NOVEL PYRIDINE OXIDE COMPOUND, AND PROCESS FOR PRODUCING CARBOXYLIC ACID DERIVATIVE AND OPTICALLY ACTIVE CARBOXYLIC ACID DERIVATIVE WITH THE USE OF THE SAME
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The invention relates to a pyridine oxide compound represented by formula (I), an optically active compound thereof, a salt thereof and a hydrate thereof, and, in the presence of the compound as a catalyst, performing 1) a method for producing an ester compound or an amide compound from a carboxylic acid equivalent and an alcohol or an amine, 2) an asymmetric esterification reaction or 3) an asymmetric amidation reaction. In formula (I), each R1 may be the same as the other R1 or different and each R1 represents an alkyl group, an aromatic group, a heterocyclic group, a carboxyl group, an ester group, a cyano group, a halogen atom, an oxygen atom, a sulfur atom or a nitrogen atom; each R2 may be the same as the other R2 or different and each R2 represents a hydrogen atom, an alkyl group, an aromatic group, a heterocyclic group, a carboxyl group, an ester group, a cyano group, a halogen atom, an oxygen atom or the like, and R3 and R4 may be the same or different and R3 and R4 each represent a hydrogen atom, an alkyl group, an aromatic group, a heterocyclic group, a carboxyl group, an ester group, a cyano group, a halogen atom, an oxygen atom or the like.
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Page/Page column 4
(2009/04/24)
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- Mixed effect of the supporting electrolyte and the zinc anode in the electrochemical homocoupling of 2-bromopyridines catalyzed by nickel complexes in an undivided cell
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Nickel-catalyzed electroreductive homocoupling of 2-bromomethylpyridines and 2-bromopyridine has been investigated in an undivided cell in the presence of a zinc sacrificial anode. A series of reactions were performed with various types and concentrations of supporting electrolyte. It was observed that a key step in this process is the formation of an arylzinc through a nickel-zinc transmetalation. This intermediate can be transformed back to the reactive arylnickel species to afford the homocoupling as the final product. The back process from the arylzinc intermediate is, however, suppressed in the presence of high concentration (0.2 M) of tetraalkylammonium salts. On the contrary, with NaI, the formation of the dimer is not prevented, whatever the NaI concentration.
- De Franca, Kelnner W. R.,De Lira Oliveira, Jadson,Florencio, Tupolevck,Da Silva, Aderivaldo P.,Navarro, Marcelo,Leonel, Eric,Nedelec, Jean-Yves
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p. 10778 - 10781
(2007/10/03)
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- Reactions of tris(2-pyridyl)phosphine oxides with electrophiles: Formation of 5-substituted 2, 2′-bipyridyls
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The reaction of tris (2-pyridyl)phosphine oxides with benzeneselenenyl chloride in methanol gave the corresponding 5-phenylseleno-2, 2′-bipyridyls together with a small amount of 2, 2′-bipyridyls. Similarly, the reaction with arenesulfenyl chlorides in aqueous acetonitrile afforded two kinds of coupling products, 5-phenylthio-2, 2′-bipyridyls and 2, 2′-bipyridyls. While in the reaction with arenesulfinyl chlorides in aqueous acetonitrile, four corresponding bipyridyl derivatives, 2, 2′-bipyridyls, 5-aryhhio-2, 2′-bipyridyls, 5-arylsulfinyl-2, 2′-bipyridyls, and 5-arylsulfonyl-2, 2′-bipyridyls, were formed.
- Uchida, Yuzuru,Matsumoto, Masami,Kawamura, Haruyasu
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- Electrochemical homocoupling of 2-bromomethylpyridines catalyzed by nickel complexes
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2,2′-Bipyridine (bpy) and a series of dimethyl-2,2′-bipyridines were synthesized from 2-bromopyridine and 2-bromomethylpyridines, respectively, using an electrochemical process catalyzed by nickel complexes. The method is simple and efficient, with isolated yields between 58 and 98% according to the structure. We first studied the influence of the presence and the position of the methyl group on the yield, using N,N-dimethylformamide (DMF) or acetonitrile (AN) as the solvent, NiBr2bpy as the catalyst, and Zn as the sacrificial anode, in an undivided cell and at ambient temperature. On the basis of a better understanding of the reaction mechanism based on electroanalytical studies, we could improve the dimerization both by substituting the catalyst ligand (bpy) by the reagent itself, i.e., 2-bromomethylpyridine or 2-bromopyridine, and by using Fe instead of Zn as the sacrificial anode.
- De Franca, Kelnner W. R.,Navarro, Marcelo,Leonel, Eric,Durandetti, Muriel,Nedelec, Jean-Yves
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p. 1838 - 1842
(2007/10/03)
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- ARYL BORATES
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The invention provides a process for covalently coupling organic compounds which comprises reacting an aromatic ring compound having a halogen or halogen-like substituent at a coupling position with a diboron derivative in the presence of a Group VIII metal catalyst and a suitabIe base. The invention also provides useful arylboron intermediates.
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- Unusual formation of 5-halo-2,2'-bipyridyls by treatment of tris(2-pyridyl)phosphine derivatives with halogens
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Reaction of tris(2-pyridyl)phosphine with chlorine in dichloromethane or acetonitrile gave chlorotris(2-pyridyl)phosphonium chloride which afforded a coupling product, 2,2'-bipyridyl, by treating with dilute HCl. Treatment of tris(2-pyridyl)phosphine or tris(2-pyridyl)phosphine oxide with chlorine or bromine in methanol gave unusual 5-halo-2,2'-bipyridyl as a major coupling product. This is undoubtedly an electrophilic substitution on a pyridyl ring in the pentacovalent phosphorane.
- Uchida,Kajita,Kawasaki,Oae
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p. 4077 - 4080
(2007/10/02)
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- Synthesis of bis(trifluoromethyl)-2,2'-bipyridines by nickel catalysed homocoupling reactions
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Bis(trifluoromethyl)-2,2'-bipyridines have been synthesized in moderate yields by nickel or palladium catalysed homocoupling of 2-chloro-(trifluoromethyl)pyridines.
- Chan,Tse
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p. 1929 - 1934
(2007/10/02)
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- Synthesis, Luminescence Quantum Yields, and Lifetimes of Trischelated Ruthenium(II) Mixed-ligand Complexes Including 3,3'-Dimethyl-2,2'-bipyridyl
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New five complexes of the type of X2(x=1,2,3, L=2,2'-bipyridyl or 1,10-phenanthroline, dmby=3,3'-dimethyl-2,2'-bipyridyl, X=halide ion) have been synthesized in order to investigate the effects of two methyl groups of dmby on the absorption and emission spectra, luminescence quantum yields, and lifetimes.Values of the radiative and nonradiative rate constants have been calculated from these data at 77 K.Although the absorption and emission maxima and the lifetimes are not much affected by the dmby ligand substitution, the molar extinction coefficients and emission quantum yields are decreased compared with trischelated complexes of the parent bipyridyl or phenanthroline ligands.At 25 deg C the emission yields of the complexes containing dmby decrease by 3-4 orders of magnitude than at 77 K.Possible causes of the decrease in the quantum yields are discussed.
- Nakamaru, Katsumi
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p. 2697 - 2705
(2007/10/02)
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