- On the feasibility of nickel-catalyzed trifluoromethylation of aryl halides
-
A computational screening of 42 bidentate phosphines (PP) has yielded promising candidates for Ph-CF3 reductive elimination from Ni(II) complexes of the type [(PP)Ni(Ph)(CF3)]. The computed barriers and synthetic accessibility consid
- Jover, Jess,Miloserdov, Fedor M.,Benet-Buchholz, Jordi,Grushin, Vladimir V.,Maseras, Feliu
-
-
Read Online
- Catalytic one-pot three-component synthesis of 3,3′-disubstituted oxindoles and spirooxindole pyrans by mixed ligand transition metal complexes
-
Abstract: New three-component reaction was developed via one-pot strategy for the synthesis of functionalized 3,3′-disubstituted oxindoles and spirooxindole through the reaction among isatin, malononitrile, and acetone/indole/nitromethane/acetylacetone/di
- Hegade, Sujit,Gaikwad, Gautam,Jadhav, Yuvraj,Pore, Avinash,Mulik, Abhijeet
-
-
- Synthesis and biological evaluation of alanine derived bioactive P-toluenesulphonamide analogs
-
Sulphonamides and carboxamides have great pharmacological importance. The purpose of the study was to synthesize alanine-derived bioactive sulphonamides bearing carboxamides and evaluate their biological activi-ties. The reaction of p-toluenesulphonyl chloride with L-alanine afforded compound 1, which was acetylated to obtain compound 2. The chlorina-tion and ammonolysis of compound 2 gave the carboxamide backbone (3) which was coupled with aryl/heteroaryl halides to afford the hybrid compounds 4, 5 and 6. Structures were confirmed by FTIR,1 H-NMR,13 C-NMR spectra and elemental analytical data. The in vitro antimicrobial properties were determined by agar dilution, and the antioxidant properties were also investigated. Molecular docking interactions of the analogues were determined using PyRx. Compounds 4, 5 and 6 exhibited excellent in vitro antimi-crobial properties in the range of 0.5-1.0mg/ml while compounds 1and 2 had half-maximal inhibitory concentration (IC50) of 1.11±0.15μg/ml and 1.12±0.13μg/ml respectively. For the molecular docking studies, compounds 5 and 6 displayed the best antitrypanosomal activity with binding affinities of-13.95 and-13.51kcal/mol respectively while compound 4 showed the highest in silico antimalarial activity having binding affinity of-11.95kcal/mol. All the alanine derived sulphonamides were observed to be potential antimicrobial, antioxidant, antitrypanosomal and antimalarial agents following the biological activities studies.
- Amasiatu, Ifeanyi S.,Egbujor, Melford C.,Egu, Samuel A.,Egwuatu, Pius I.,Eze, Florence U.,Okoro, Uchechukwu C.
-
p. 6449 - 6458
(2020/10/27)
-
- Catalysis of Cross-Coupling and Homocoupling Reactions of Aryl Halides Utilizing Ni(0), Ni(I), and Ni(II) Precursors; Ni(0) Compounds as the Probable Catalytic Species but Ni(I) Compounds as Intermediates and Products
-
Both Ni(0) and Ni(I) compounds are believed to exhibit cross-coupling catalytic properties under various conditions, and the compounds Ni(PPh3)4 and NiCl(PPh3)3 are compared as catalysts for representative Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions. The Ni(0) compound exhibits catalytic activities, for cross-coupling of chloro and bromoanisole with phenylboronic acid and of bromobenzene with styrene, yielding results which are comparable with those of many palladium-based catalysts, but our findings with NiCl(PPh3)3 are at this point unclear. It seems to convert to catalytically active Ni(0) species under Suzuki-Miyaura reaction conditions and is ineffective for Heck-Mizoroki cross-coupling. The paramagnetic Ni(I) compounds NiX(PPh3)3 (X = Cl, Br, I) are characterized for the first time by 1H NMR spectroscopy and are found to exhibit broad meta and para resonances at δ 9-11 and 3-4, respectively, and very broad ortho resonances at δ 46; these resonances are very useful for detecting Ni(I) species in solution. The chemical shifts of NiCl(PPh3)3 vary with the concentration of free PPh3, with which it exchanges, and are also temperature-dependent, consistent with Curie law behavior. The compound trans-NiPhCl(PPh3)2, the product of oxidative addition of chlorobenzene to Ni(PPh3)4 and a putative intermediate in cross-coupling reactions of chlorobenzene, is found during the course of this investigation to exhibit entirely unanticipated thermal lability in solution in the absence of free PPh3. It readily decomposes to biphenyl and NiCl(PPh3)2 in a reaction relevant to the long-known but little-understood nickel-catalyzed conversion of aryl halides to biaryls. Ni(I) and biphenyl formation is initiated by PPh3 dissociation from trans-NiPhCl(PPh3)2 and formation of a dinuclear intermediate, a process which is now better defined using DFT methodologies.
- Manzoor, Adeela,Wienefeld, Patrick,Baird, Michael C.,Budzelaar, Peter H.M.
-
p. 3508 - 3519
(2017/10/03)
-
- A synthesis method according to sets up qu tan hydrobromide
-
The invention discloses a synthesis method of eletriptan hydrobromate, which comprises the following steps: reacting (R)-1-acetyl-3-(N-methylpyrrolidinyl-2-methy)-5-bromo-1H-indole and metal in an organic solvent to form a metal complex, reacting the metal complex with a boron reagent in an organic solvent to form aryl borane or aryl borate, carrying out acid-catalyzed hydrolysis to obtain aryl boric acid, and carrying out coupling and hydrolysis on the aryl boric acid and 2-chloroethylphenyl sulfone under the actions of a catalyst and an alkali to obtain eletriptan, or directly carrying out coupling and hydrolysis on the metal complex and 2-chloroethylphenyl sulfone to obtain eletriptan; and carrying out salification on the eletriptan and hydrobromic acid in an organic solvent to finally obtain the eletriptan hydrobromate. The method is simple to operate, has the advantages of high safety, high stability, low cost and higher yield, and is suitable for industrial production.
- -
-
Paragraph 0053-0054
(2017/10/22)
-
- Use of metal-accumulating plants for implementing chemical reactions
-
The use of metal-accumulating plants for implementing chemical reactions.
- -
-
Page/Page column 49
(2015/10/28)
-
- USE OF COMPOSITIONS OBTAINED BY CALCINING PARTICULAR METAL-ACCUMULATING PLANTS FOR IMPLEMENTING CATALYTICAL REACTIONS
-
The use of metal-accumulating plants for implementing chemical reactions especially catalytical reactions.
- -
-
Paragraph 0783-0785
(2016/01/25)
-
- NICKEL PRE-CATALYSTS AND RELATED COMPOSITIONS AND METHODS
-
Described herein are nickel pre-catalysts and related compositions and methods. The nickel pre-catalysts may be activated to form catalysts which may be utilized in organic reactions.
- -
-
Page/Page column 40
(2015/05/26)
-
- Tandem redox mediator/Ni(II) trihalide complex photocycle for hydrogen evolution from HCl
-
Photoactivation of M-X bonds is a challenge for photochemical HX splitting, particularly with first-row transition metal complexes because of short intrinsic excited state lifetimes. Herein, we report a tandem H2 photocycle based on combination of a non-basic photoredox phosphine mediator and nickel metal catalyst. Synthetic studies and time-resolved photochemical studies have revealed that phosphines serve as photochemical H-atom donors to Ni(II) trihalide complexes to deliver a Ni(I) centre. The H2 evolution catalytic cycle is closed by sequential disproportionation of Ni(I) to afford Ni(0) and Ni(II) and protolytic H2 evolution from the Ni(0) intermediate. The results of these investigations suggest that H2 photogeneration proceeds by two sequential catalytic cycles: a photoredox cycle catalyzed by phosphines and an H2-evolution cycle catalyzed by Ni complexes to circumvent challenges of photochemistry with first-row transition metal complexes.
- Hwang, Seung Jun,Powers, David C.,Maher, Andrew G.,Nocera, Daniel G.
-
p. 917 - 922
(2015/02/05)
-
- A broadly applicable strategy for entry into homogeneous nickel(0) catalysts from air-stable nickel(II) complexes
-
A series of air-stable nickel complexes of the form L2Ni(aryl) X (L = monodentate phosphine, X = Cl, Br) and LNi(aryl)X (L = bis-phosphine) have been synthesized and are presented as a library of precatalysts suitable for a wide variety of nickel-catalyzed transformations. These complexes are easily synthesized from low-cost NiCl2·6H2O or NiBr 2·3H2O and the desired ligand followed by addition of 1 equiv of Grignard reagent. A selection of these complexes were characterized by single-crystal X-ray diffraction, and an analysis of their structural features is provided. A case study of their use as precatalysts for the nickel-catalyzed carbonyl-ene reaction is presented, showing superior reactivity in comparison to reactions using Ni(cod)2. Furthermore, as the precatalysts are all stable to air, no glovebox or inert-atmosphere techniques are required to make use of these complexes for nickel-catalyzed reactions.
- Standley, Eric A.,Smith, Stacey J.,Mueller, Peter,Jamison, Timothy F.
-
supporting information
p. 2012 - 2018
(2014/05/20)
-
- Straightforward synthesis of substituted dibenzyl derivatives
-
The C-C bond formation by homogeneous catalysis is a powerful tool in organic synthesis. The replacement of noble metal by cheaper one for already reported methodologies is of interest for an economical purpose. The attractivity of such replacement is also enhanced if a first raw transition metal is found to be active in several processes. This work demonstrates that a common nickel complex can be used for a two-step cross-coupling procedure, namely a homocoupling reaction of benzyl derivatives and a subsequent Suzuki reaction. These consecutive reactions permit the synthesis of new polyfunctionalized dibenzyl compounds.
- Mboyi, Clève D.,Gaillard, Sylvain,Mabaye, Mbaye D.,Pannetier, Nicolas,Renaud, Jean-Luc
-
p. 4875 - 4882
(2013/06/26)
-
- Synthesis, crystal structures and spectral studies of square planar nickel(II) complexes containing an ONS donor Schiff base and triphenylphosphine
-
Five mononuclear nickel(II) complexes, viz. [Ni(L1)(PPh3)] (1), [Ni(L2)(PPh3)] (2), [Ni(L3)(PPh3)] (3), [Ni(L4)(PPh3)] (4) and [Ni(L5)(PPh3)] (5) (where L1, L2, L3, L4 and L5 are dianions of N-(2-mercaptophenyl)salicylideneimine, 5-methyl-N-(2-mercaptophenyl)salicylideneimine, 5-chloro-N-(2-mercaptophenyl)salicylideneimine, 5-bromo-N-(2-mercaptophenyl)salicylideneimine and N-(2-mercaptophenyl)naphthylideneimine, respectively), have been synthesized and characterized by means of elemental analysis, electronic, IR, 1H, 13C and 31P NMR spectroscopy. Single crystal X-ray analysis of two of the complexes (1 and 5) has revealed the presence of a square planar coordination geometry (ONSP) about nickel. The crystal structures of the complexes are stabilized by intermolecular π-π stacking between the ligands (L) and by various C-H···π interactions.
- Muthu Tamizh,Mereiter, Kurt,Kirchner, Karl,Ramachandra Bhat,Karvembu
-
p. 2157 - 2164
(2009/12/26)
-
- Influence of SiMe3 substituents on structures and hydrosilylation activities of ((SiMe3)1 or 2-Indenyl)Ni(PPh3)Cl
-
This report examines the effect of substituents R on structures and reactivities of the complexes (R-Ind)Ni(PPh3)Cl (R-Ind = 1-Me-indenyl, 1; 1-SiMe3-indenyl, 2; 1,3-(SiMe3) 2-indenyl, 3). NMR studies indicate that a relatively facile dissociation of PPh3 takes place in solutions of complex 3 (ΔG* ≈ 10 kcal/mol in C6D6) but not those of complexes 1 and 2, implying that the presence of Ind substituents at the 1- and 3-positions can influence the kinetic lability of PPh3. X-ray analyses have also shown that the PPh3 ligand and the SiMe 3 group adjacent to it in complex 3 experience some steric repulsion, which is manifested in angular deformations (out-of-plane bending of the SiMe3 group by about 0.56-0.65 A and 5-10° variations in the P-Ni-Cl and P-Ni-C3 angles) and a somewhat longer Ni-P bond (ca. 2.19 A). Reactivity studies have shown that complexes 1-3 are effective precatalysts for the addition of PhSiH3 to styrene in the presence of the cationic initiator NaBPh4; α-addition of the silyl moiety takes place regioselectively to give PhCH(Me)(SiPhH2). The catalytic activities depend on the styrene:PhSiH3 ratio but not the Ind substituents; thus, catalytic turnover numbers increase from ca. 75 with a 1:1 ratio to ca. 95 with a 1:1.5 ratio for all three precursors. The hydrosilylation can also proceed in the absence of initiator, but in this case the activities are strongly dependent on Ind substituents, increasing in the order 1-Me-Ind 3-Ind 3) 2-Ind.
- Chen, Yaofeng,Sui-Seng, Christine,Boucher, Sylvain,Zargarian, Davit
-
p. 149 - 155
(2008/10/09)
-
- Process design and scale-up of the synthesis of 2,2′:5′,2′-terthienyl
-
The objective of this study was the design of a scaleable process for the synthesis of 3-4 mol of α-terthienyl from 2,5-dibromothiophene and thienylmagnesium bromide in a 10-L stirred tank reactor. In THF the Grignard reagent, thienylmagnesium bromide, was readily formed from 2-bromothiophene and magnesium. To avoid crystallization the maximal concentration was limited to 1.4 M. Furthermore, the novel combination of THF and NiCl2[bis(diphenylphosphino)benzene] allows for fast double coupling of the Grignard reagent with 2,5-dibromothiophene. The concentration of catalyst could be limited to 0.5 mol % based on the amount of 2,5-dibromothiophene. An adapted workup procedure was developed, in which n-octane was used to separate the magnesium salts from the desired product. The reaction was performed in a (semi)batch-wise operated reactor. A global model for the coupling step proved to predict the results at 0.1-, 1-, and 10-L scales very accurately. The heat of reaction evolved in the coupling step was valorized and could be handled easily. Mixing of the feed stream and the reactor content proved to be another important factor in the scaling-up of the α-terthienyl synthesis.
- Smeets,Meijer,Meuldijk,Vekemans,Hulshof
-
-
- Reaction of vinyl chloride with late transition metal olefin polymerization catalysts
-
The reactions of vinyl chloride (VC) with representative late metal, single-site olefin dimerization and polymerization catalysts have been investigated. VC coordinates more weakly than ethylene or propylene to the simple catalyst (Me2bipy)PdMe+ (Me2bipy = 4,4Κ-Me2-2,2Κ-bipyridine). Insertion rates of (Me2bipy)Pd(Me)(olefin)+ species vary in the order VC > ethylene > propylene. The VC complexes (Me2-bipy)Pd(Me)(VC)+ and (α-diimine)Pd(Me)(VC)+ α-diimine = (2,6-iPr2-C6H3) N=CMeCMe=N(2,6-iPr2-C6H3)) undergo net 1,2 VC insertion and β-Cl elimination to yield Pd-Cl species and propylene. Analogous chemistry occurs for (pyridine-bisimine)MCl2/MAO catalysts (M = Fe, Co; pyridine-bisimine = 2,6-{(2,6-iPr2-C6H3) N=CMe}2-pyridine) and for neutral (sal)Ni(Ph)PPh3 and (P-O)Ni(Ph)PPh3 catalysts (sal = 2-{C-(H)=N(2,6-iPr2-C6H3)} -6-Ph-phenoxide; P-O = {Ph2PC(SO3Na)=C(p-tol)O}), although the initial metal alkyl VC adducts were not detected in these cases. These results show that the LnMCH2CHCIR species formed by VC insertion into the active species of late metal olefin polymerization catalysts undergo rapid β-Cl elimination which precludes VC polymerization. Termination of chain growth by β-Cl elimination is the most significant obstacle to metal-catalyzed insertion polymerization of VC.
- Foley, Stephen R.,Stockland Jr., Robert A.,Shen, Han,Jordan, Richard F.
-
p. 4350 - 4361
(2007/10/03)
-
- Preparation of Four-membered Phosphonickelocycles. Unusual Facile Stabilization of Five-co-ordinate Complexes
-
Three different types of organometallic compounds (R = Ph 1 or Et 1'), (R = Ph 2 or Et 2') and (R = Ph 3 or Et 3') have been obtained from 1 equivalent of PR2(C6Cl5) (R = Ph or Et), (cod = cis,cis-cycloocta-1,5-diene), and L = PMe2Ph a, PEt3 b, P(CH2Ph)3 c or PPh3 d.Complexes 2 evolve in solution, either to 1 and , or to 3 by breaking of the Ni-P bond of the four-membered ring by free phosphine.The selective preparation of compounds 1 or 3 can be achieved by performing the oxidative-addition reaction in the absence or with 2 equivalents of L respectively.When 1 equivalent of a diphosphine was used in the oxidative-addition reaction a mononuclear five-co-ordinate complex was obtained, 4 .However, dppm (Ph2PCH2PPh2) acts as a monodentate ligand to give the five-co-ordinate compound .Complexes 2, 2' show preferentially a cis geometry, 1' is trans, and 3, 3' have the L ligands in trans position.Insertion of CO or alkynes into the Ni-C bond was not observed.Compounds 1 and 1' in the presence of neutral ligands L = CO or PR3 (PR3 = PMe2Ph a or PEt3 b) gave five-co-ordinate complexes without cleavage of the Ni-P bond of the ring.Stabilization of the four-membered ring is achieved when two bidentate ligands are present or in the five-co-ordinate compound .Two bidentate ligands are also needed to stabilize the formation of five-co-ordinate complexes.The molecular structures of complexes 1', 3b, and were determined by single-crystal X-ray diffraction.
- Font-Bardia, Merce,Gonzalez-Platas, Javier,Muller, Guillermo,Panyella, David,Rocamora, Merce,Solans, Xavier
-
p. 3075 - 3084
(2007/10/02)
-
- Homogeneous Isomerization of 1-Butene Catalyzed by -NaBH4 Systems (M=Co, Ni, X=Halides, SCN, PR3=PPhnEt3-n) - Acceleration by Phosphine Addition and Stereoselectivity
-
The stoichiometric or a little excess amount of NaBH4 was treated with (M=Co, Ni, X=halides, SCN, PR3=PPhnEt3-n) in THF-1,2-dimethoxyethane to form monohydride species which were active for isomerization of 1-butene.The reaction was accelerated by excess PPh3 in -NaBH4 systems.Other catalytic systems have optimum ratios of excess phosphine to metal for getting maximum activities.Thiocyanate-metal complexes are the most active in each Co- and Ni-catalyst system.Cis-selectivity depends on the cone angle of PR3, the size of anion ligands, and the congested structure of the complexes.
- Kanai, Hiroyoshi,Sakai, Shigeyoshi,Sakatani, Takenobu
-
p. 1589 - 1594
(2007/10/02)
-
- PALLADIUM AND NICKEL-CATALYZED PERFLUOROALKYLATION OF ALDEHYDES USING ZINC AND PERFLUOROALKYL HALIDES
-
A room temperature method for the conversion of perfluoroalkyl iodides to α-perfluoroalkyl carbinols under Pd or Ni catalysis is reported.The use of trifluoromethyl bromide provides an economical procedure for trifluoromethyl substituted carbinols.
- O'Reilly, Neil J.,Maruta, Masamichi,Ishikawa, Nobuo
-
p. 517 - 520
(2007/10/02)
-
- The Electro-Syntheses of Anhydrous Metal Chloride Complexes of Iron, Cobalt, and Nickel
-
The electro-syntheses of the anhydrous metal(II) chlorides od Fe, Co, and Ni are described.The appropriate metal is present in the form of a sacrificial anode and the reaction is carried out in an undivided cell with ethanolic solutions of hydrogen chloride.The primary products, MCl2 . n EtOH (1 - 3), are obtained in yields of 83 - 100percent based upon the current consumed and are converted into 4 - 6 upon reaction with THF, into 7 - 12 upon reaction with triorganophosphanes and into the tetrachlorometallate(II) complexes 13 - 15 upon reaction with Cl.Electrochemical reduction of nickel(II) chloride and triphenylphosphane (1 : 3) in THF leads to the formation of chlorotris(triphenylphosphane)nickel(I) (18) in 65percent yield.
- Lehmkuhl, Herbert,Mehler, Klaus,Hauschild, Gerlinde
-
p. 438 - 444
(2007/10/02)
-
- Simultaneous conversion of Ni-PR3 and B-H to Ni-H and B-PR3 linkages by thermal rearrangement of d8 closo-bis(triarylphosphine)nickelacarboranes. Crystal and molecular structure of [closo-3-(μ-CO)-8-PPh3-3,1,2-NiC2B9H 10]2: A dimeric nickelacarborane complex containing a metal-metal bond
-
The reaction of L2NiCl2 (L = PR3) species with nido-7,8-, nido-7,9-, or nido-2,9-C2B9H112- ions led to the formation of the corresponding icosahedral bis(phosphine)nickelacarboranes in high yield. Heating members of the closo-3,3-(triarylphosphine)2-3,1,2-NiC2B 9H11 series at 80°C in benzene solution led to the formation of the corresponding [closo-3,8-(triarylphosphine)2-3-H-3,1,2-NiC2B 9H11] by interchange of phosphine and hydrido ligands. No intermediates were observed, and the reaction was specific for the bis(triarylphosphine)-3,1,2-NiC2 icosahedral system among those investigated. The dimeric nickelacarborane carbonyl [closo-(3-(μ-CO)-8-PPh3-3,1,2-NiC2B9H 11)2] was prepared by a variety of routes such as the reaction of [closo-3,3-(PPh3)2-3,1,2-NiC2B 9H11] (1a) with CO in benzene at 80°C. A variety of ligand substitution reactions were carried out with 1a. The mechanism of the phosphine-hydride ligand interchange is discussed. The dimeric nickelacarborane complex was characterized by an X-ray diffraction study. Amber crystals were triclinic, space group P1, with a = 13.319 (4) A?, b = 10.039 (3) A?, c = 9.813 (3) A?, α = 80.00 (1)°, β = 82.91 (1)°, γ = 110.32 (1)°, and Z = 1. The structure was solved by conventional heavy-atom methods to a final discrepancy index of R = 0.057 for 2233 independent observed reflections. The complex contains a metal-metal bond (2.477 (2) A?) and two metal-bridging carbon monoxide groups.
- King III,Miller, Steven B.,Knobler, Carolyn B.,Hawthorne, M. Frederick
-
p. 3548 - 3554
(2008/10/08)
-
- Organonickel(II) Complexes Containing Carbon-bonded Heterocycles as a Ligand
-
Oxidative addition reactions of 2- and 3-chloropyridines and of 2-chloropyrazine to tetrakis(triphenylphosphine)nickel(0) occurred in toluene at ambient temperature to afford dinuclear nickel(II) complexes containing carbon-bonded heterocycles as a ligand.They are quite stable and the bridging chloride was readily substituted by other halides and pseudohalides preserving the dinuclear structure. 8-Chloroquinoline yielded a mononuclear complex as an exception.These novel organonickel(II) complexes were characterized by analytical and molecular weight data together with IR, 1H NMR, and 13C NMR spectra.Di-μ-chloro-bis(2-pyridyl)bis(triphenylphosphine)dinickel(II) was found to be an excellent catalyst for selective cross coupling of 2-chloropyridine with methylmagnesium bromide.
- Isobe, Kiyoshi,Nakamura, Yukio,Kawaguchi, Shinichi
-
p. 139 - 145
(2007/10/02)
-
