- A Robust Pd-Catalyzed C-S Cross-Coupling Process Enabled by Ball-Milling
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An operationally simple mechanochemical C-S coupling of aryl halides with thiols has been developed. The reaction process operates under benchtop conditions without the requirement for a (dry) solvent, an inert atmosphere, or catalyst preactivation. The reaction is finished within 3 h. The reaction is demonstrated across a broad range of substrates; the inclusion of zinc metal has been found to be critical in some instances, especially for coupling of alkyl thiols.
- Browne, Duncan L.,Jones, Andrew C.,Nicholson, William I.,Smallman, Harry R.
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supporting information
p. 7433 - 7438
(2020/10/09)
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- C[sbnd]S cross-coupling catalyzed by a series of easily accessible, well defined Ni(II) complexes of the type [(NHC)Ni(Cp)(Br)]
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The synthesis, characterization and catalytic evaluation of a series of NHC-Ni(II) complexes 1-Ni (-Me), 2-Ni (-nBu) and 3-Ni (-Bn) bearing a phthalimide fragment and a cyclopentadienyl (Cp) ligand is reported. The complexes were evaluated in C
- Rodríguez-Cruz, Mario A.,Hernández-Ortega, Simón,Valdés, Hugo,Rufino-Felipe, Ernesto,Morales-Morales, David
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p. 193 - 198
(2020/02/13)
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- Deprotonated Salicylaldehyde as Visible Light Photocatalyst
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Salicylaldehyde is established as an efficient visible light photocatalyst for the first time. Compared to other simple aldehyde analogies, salicylaldehyde has a unique deprotonative red-shift from 324 to 417 nm and gives rise to the remarkable increase of fluorescence quantum from 0.0368 to 0.4632, thus enabling salicylaldehyde as a visible light (>400 nm) photocatalyst. The experimental investigations suggest that the reactive radical species are generated by sensitization of the substrates by the deprotonated salicylaldehyde through an energy-transfer pathway. Consequently, the C-C cleaving alkylation reactions of N-hydroxyphthalimide esters proceed smoothly in the presence of as low as 1 mol % of salicylaldehyde under the visible-light irradiation, affording desired alkylation products with up to 99% yields. Application in visible-light induced aerobic oxidation of N-alkylpyridinium salts is also reported.
- Zhuang, Yan-Jun,Qu, Jian-Ping,Kang, Yan-Biao
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p. 4386 - 4397
(2020/03/05)
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- Iodosylbenzene Coordination Chemistry Relevant to Metal-Organic Framework Catalysis
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Hypervalent iodine compounds formally feature expanded valence shells at iodine. These reagents are broadly used in synthetic chemistry due to the ability to participate in well-defined oxidation-reduction processes and because the ligand-exchange chemist
- Cardenal, Ashley D.,Maity, Asim,Gao, Wen-Yang,Ashirov, Rahym,Hyun, Sung-Min,Powers, David C.
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supporting information
p. 10543 - 10553
(2019/09/13)
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- SPS–Ni(II) pincer compounds of the type [Ni(phPS2)(P(C6H4-4-R)3)] Synthesis, characterization and catalytic evaluation in C–S cross-coupling reactions
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The synthesis and characterization of a series of SPS–Ni(II) pincer complexes with different para-substituted triphenylphosphines has been performed. The molecular structure of [Ni(phPS2)(PPh3)] (1) (phPS2H2 = PhP(C6H4-2-SH)2, bis(phenyl-2-thiol)phenylphosphine) was unequivocally determined by single crystal X-ray diffraction analysis. The metal centre exhibited a slightly distorted square planar geometry. The complexes showed a high catalytic activity in the C–S cross-coupling reaction of both alkyl- and aryl-disulfides with iodobenzenes for the production of non-symmetric sulfides. In general, the different para-substituted triphenylphosphine ligands do not affect the catalytic performance of the SPS–Ni(II) complexes. However, activity of the catalyst decreases with the steric hindrance of the different alkyl groups in the disulphide substrates.
- Gómez-Benítez, Valente,Valdés, Hugo,Hernández-Ortega, Simón,Germán-Acacio, Juan Manuel,Morales-Morales, David
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p. 144 - 148
(2017/10/13)
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- Nickel Phosphite/Phosphine-Catalyzed C-S Cross-Coupling of Aryl Chlorides and Thiols
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A method for the coupling of aryl chlorides and thiophenols using an air-stable nickel(0) catalyst is described. This thioetherification procedure can be effectively applied to a range of electronically diverse aryl/heteroaryl chlorides without more expensive metal catalysts such as palladium, iridium, or ruthenium. This investigation also illustrates both, a variety of thiol coupling partners and, in certain cases, the use of Cs2CO3.
- Jones, Kieran D.,Power, Dennis J.,Bierer, Donald,Gericke, Kersten M.,Stewart, Scott G.
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supporting information
p. 208 - 211
(2018/01/17)
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- Transalkylation of alkyl aryl sulfides with alkylating agents
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The reaction of methyl iodide with tert-butylphenylsulfide in DMF leads to a transalkylation that produces methylphenylsulfide. This transalkylation reaction was further studied by 1H NMR spectroscopy. The polarity of the solvent, the electron density on the sulfur atom, and the strength of the alkylating agent (MeI, EtI, BuI, dimethyl sulfate, or dimethyl carbonate) played important roles in the reaction. The suggested mechanism of the reaction involves the formation of a dialkyl aryl sulfonium salt that subsequently eliminates the radical. This mechanism was supported by the observation of higher conversion rates for compounds with more branched alkyl groups on the sulfur atom, which may lead to the formation of more stable radicals.
- Nawrot, Daria,Koleni?, Marek,Kune?, Ji?í,Kostelansky, Filip,Miletin, Miroslav,Novakova, Veronika,Zimcik, Petr
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p. 594 - 599
(2018/01/01)
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- Oxidation of Organosulfides to Organosulfones with Trifluoromethyl 3-Oxo-1λ 3,2-benziodoxole-1(3 H)-carboxylate as an Oxidant
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An alternative approach is described for the oxidation of organosulfides to the corresponding organosulfones by using trifluoromethyl 3-oxo-1λ 3,2-benziodoxole-1(3 H)-carboxylate as an oxidant. The oxidation of the sulfides was performed by using 2.4 equivalents of the oxidant in refluxing acetonitrile. The oxidation products were isolated in good to excellent yields.
- Mangaonkar, Saeesh R.,Kole, Priyanka B.,Singh, Fateh V.
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supporting information
p. 199 - 202
(2017/09/28)
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- Fundamental Difference in Reductive Lithiations with Preformed Radical Anions versus Catalytic Aromatic Electron-Transfer Agents: N,N-Dimethylaniline as an Advantageous Catalyst
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The reductive lithiation of phenyl thioethers, or alkyl chlorides, by either preformed aromatic radical anions or by lithium metal and an aromatic electron-transfer catalyst, is commonly used to prepare organolithiums. Revealed herein is that these two methods are fundamentally different. Reductions with radical anions occur in solution, whereas the catalytic reaction occurs on the surface of lithium, which is constantly reactivated by the catalyst, an unconventional catalyst function. The order of relative reactivity is reversed in the two methods as the dominating factor switches from electronic to steric effects of the alkyl substituent. A catalytic amount of N,N-dimethylaniline (DMA) and Li ribbon can achieve reductive lithiation. DMA is significantly cheaper than alternative catalysts, and conveniently, the Li ribbon does not require the removal of the oxide coating when DMA is used as the catalyst.
- Kennedy, Nicole,Liu, Peng,Cohen, Theodore
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supporting information
p. 383 - 386
(2016/01/25)
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- Reductive Lithiation in the Absence of Aromatic Electron Carriers. A Steric Effect Manifested on the Surface of Lithium Metal Leads to a Difference in Relative Reactivity Depending on Whether the Aromatic Electron Carrier Is Present or Absent
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One of the most widely used methods of preparation of organolithium compounds is by the reductive lithiation of alkyl phenyl thioethers or, usually less conveniently, alkyl halides with either aromatic radical-anions of lithium or lithium metal in the presence of an aromatic electron-transfer catalyst. Here we present results showing that lithium dispersion can achieve reductive lithiation in the absence of the electron-transfer agent. This procedure is more efficient, and surprisingly, the order of reactivity of substrates is reversed depending on whether the electron-transfer agent is present or absent. For example, in the presence of a preformed radical-anion, tert-butyl phenyl sulfide cleaves significantly faster than methyl phenyl sulfide, whereas in the absence of the radical-anion, it is just the opposite. Density functional theory calculations reveal that the exothermicity of the cleavage of the C-S bond in alkyl phenyl thioethers on the lithium surface is dependent on the size of the alkyl group, the smaller the alkyl group the greater the exothermicity. The increased reactivity is attributed to the smaller steric repulsion between the alkyl group and the lithium surface. The methodology includes, but may not be limited to, the lithium dispersion reductive lithiation of phenyl thioethers, alkyl chlorides, acrolein diethyl acetal, and isochroman.
- Kennedy, Nicole,Lu, Gang,Liu, Peng,Cohen, Theodore
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p. 8571 - 8582
(2015/09/15)
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- Magnetic nanoparticle-supported Pd(II)-cryptand 22 complex: An efficient and reusable heterogeneous precatalyst in the Suzuki-Miyaura coupling and the formation of aryl-sulfur bonds in honor and memory of late Prof. Mathias Mertes
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In the present work, silica-coated magnetic nanoparticles [Fe3O4@SiO2@C22-Pd(II)] were prepared and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometer, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, elemental analysis, inductively coupled plasma, thermogravimetric and differential thermal analysis. This heterogeneous catalyst is utilized as an effective catalyst for the Suzuki-Miyaura coupling of arylboronic acids and aryl halides, and the cross-coupling reaction of aryl halides and thiols. The catalyst was easily separated by magnetic decantation and the recovered catalyst was reused for five cycles without any significant loss of the catalytic activity.
- Movassagh, Barahman,Takallou, Ahmad,Mobaraki, Akbar
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- The efficiency of the metal catalysts in the nucleophilic substitution of alcohols is dependent on the nucleophile and not on the electrophile
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In this study, we investigate the effect of the electrophiles and the nucleophiles for eight catalysts in the catalytic SN1 type substitution of alcohols with different degree of activation by sulfur-, carbon-, oxygen-, and nitrogen-centered nucleophiles. The catalysts do not show any general variance in efficiency or selectivity with respect to the alcohols and follow the trend of alcohol reactivity. However, when it comes to the nucleophile, the eight catalysts show general and specific variances in the efficiency and selectivity to perform the desired substitution. Interestingly, the selectivity of the alcohols to produce the desired substitution products was found to be independent of the electrophilicity of the generated carbocations but highly dependent on the ease of formation of the cation. Catalysts based on iron(III), bismuth(III), and gold(III) show higher conversions for S-, C-, and N-centered nucleophiles, and BiIII was the most efficient catalyst in all combinations. Catalysts based on rhenium(I) or rhenium(VII), palladium(II), and lanthanum(III) were the most efficient in performing the nucleophilic substitution on the various alcohols with the O-centered nucleophiles. These catalysts generate the symmetrical ether as a by-product from the reactions of S-, C-, and N-centered nucleophiles as well, resulting in lower chemoselectivity. Who's the boss? In a comprehensive study of catalytic S N1 type direct substitution of alcohols, the catalysts do not show any general variance in efficiency or selectivity with respect to the alcohols but are highly variable with respect to the nucleophiles. The reactivity of the alcohols is independent of the electrophilicity of the generated carbocations but highly dependent on the ease of formation of the cation.
- Biswas, Srijit,Samec, Joseph S. M.
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supporting information
p. 974 - 981
(2013/08/25)
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- Heterotopic As,S,P and As,S,As ligands: Synthesis and theoretical studies
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The heterotopic As,S,P ligands 1-AsPh2-2-StBu-3-PPh2-C6H3 (2) and 1-AsPh2-2-SH-3-PPh2-C6H3 (4) and dinucleating As,S,As ligand 1,3-(AsPh2)2-2-StBu-C6H3 (3) have been synthesized and characterized. The structural motif of these compounds suggests great pot
- Sarosi, Imola,Sarosi, Menyhart B.,Loennecke, Peter,Silaghi-Dumitrescu, Luminita,Hey-Hawkins, Evamarie
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p. 1246 - 1252
(2013/10/22)
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- A highly efficient palladium-catalyzed one-pot synthesis of unsymmetrical aryl alkyl thioethers under mild conditions in water
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A palladium-catalyzed, one-pot synthesis of unsymmetrical aryl alkyl thioethers involving aryl halides (aryl bromides and chlorides), thiourea and alkyl bromides has been realized under mild conditions (room temperature to 50 °C) in water with polyoxyethanyl α-tocopheryl sebacate (PTS) as amphiphile. The PTS/water could be recycled in up to eight runs without an obvious change in its activity. Copyright
- Wang, Liang,Zhou, Wei-You,Chen, Sheng-Chun,He, Ming-Yang,Chen, Qun
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supporting information; experimental part
p. 839 - 845
(2012/05/20)
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- Efficient nickel/N-heterocyclic carbene catalyzed C-S cross-coupling
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The cross-coupling reaction of aryl halides with aliphatic and aromatic thiols catalyzed by readily available Ni(OAc)2 with N-heterocyclic carbene (NHC) is reported. Ni(OAc)2/NHC catalyst showed good activities toward various aryl halides in C-S coupling reaction, even with aryl chlorides. Reactions occurred in excellent yields, broad scope, and high tolerance of functional groups.
- Guan, Pei,Cao, Changsheng,Liu, Yun,Li, Yunfei,He, Pan,Chen, Qian,Liu, Gang,Shi, Yanhui
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supporting information
p. 5987 - 5992,6
(2012/12/12)
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- Efficient nickel/N-heterocyclic carbene catalyzed C-S cross-coupling
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The cross-coupling reaction of aryl halides with aliphatic and aromatic thiols catalyzed by readily available Ni(OAc)2 with N-heterocyclic carbene (NHC) is reported. Ni(OAc)2/NHC catalyst showed good activities toward various aryl halides in C-S coupling reaction, even with aryl chlorides. Reactions occurred in excellent yields, broad scope, and high tolerance of functional groups.
- Guan, Pei,Cao, Changsheng,Liu, Yun,Li, Yunfei,He, Pan,Chen, Qian,Liu, Gang,Shi, Yanhui
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supporting information
p. 5987 - 5992
(2013/01/13)
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- Iron-catalyzed thioetherification of thiols with aryl iodides
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FeCl3 in combination with bisphosphine ligands represents an efficient catalyst system for the cross-coupling of aryl- and alkyl thiols with aryl iodides, a broad spectrum of functional groups can be tolerated during the catalysis. The Royal Society of Chemistry 2009.
- Wu, Jhih-Ru,Lin, Che-Hung,Lee, Chin-Fa
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supporting information; experimental part
p. 4450 - 4452
(2009/12/29)
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- Indium-mediated cleavage of diphenyl diselenide and diphenyl disulfide: efficient one-pot synthesis of unsymmetrical diorganyl selenides, sulfides, and selenoesters
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A convenient and efficient method was developed for the synthesis of alkyl phenyl selenides, sulfides, and selenoesters in one-pot reaction by using indium metal. The reaction showed the selectivity for tert-alkyl, benzylic, and allylic halides over primary and secondary alkyl halides. For the reaction of primary and secondary alkyl iodides and bromides, the yields of selenides were improved by the addition of a catalytic amount of iodine.
- Munbunjong, Wanida,Lee, Eun Hwa,Ngernmaneerat, Poonlarp,Kim, Sung Jun,Singh, Gurpinder,Chavasiri, Warinthorn,Jang, Doo Ok
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experimental part
p. 2467 - 2471
(2009/08/15)
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- On the reactivity of indium(III) benzenechalcogenolates (chalcogen = sulfur and selenium) towards organyl halides for the synthesis of organyl phenyl chalcogenides
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The reactivity of indium(III) benzenechalcogenolates (chalcogen = sulfur, selenium) towards organyl halides (organyl = alkyl, allyl, benzyl, acyl) was examined. A practical one-pot method to prepare organyl phenyl chalcogenides indium metal and diphenyl dichalcogenide was found. The coupling is fairly broad in scope and generally works better organyl halides capable to produce stable carbocations.
- Peppe, Clovis,Borges De Castro, Lierson
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experimental part
p. 678 - 683
(2009/10/30)
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- Alkyl- and arylthiolation of aryl halides catalyzed by fluorinated bis-imino-nickel NNN pincer complexes [NiCl2{C5H 3N-2,6-(CHNArf)2}]
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The synthesis of bis-imino nickel(II) NNN pincer complexes of the type [NiCl2{C5H3N-2,6-(CHNArf) 2}]; Arf= C6H3-2,3-F2 (1), C6H3-2,5-F2 (2), C6H 3-3,4-F2 (3), C6H3-3,5-F2 (4), C6H2-2,3,4-F3 (5), C6H 2-2,3,6-F3 (6), C6H2-2,4,5-F 3 (7), C6H2-2,4,6-F3 (8), has been achieved and their reactivity in alkyl- and arylthiolation reactions of halobenzenes examined. The use of fluorinated substituents Arf on the imines has allowed the tuning of the electronics in these complexes and the influence of these substituents and those of the disulfides in the thiolation reactions have been analyzed.
- Baldovino-Pantaleon, Oscar,Hernandez-Ortega, Simon,Morales-Morales, David
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p. 236 - 242
(2007/10/03)
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- High yield thiolation of iodobenzene catalyzed by the phosphinite nickel PCP pincer complex: [NiCl{C6H3-2,6-(OPPh2)2}]
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[NiCl{C6H3-2,6-(OPPh2)2}] efficiently catalyzes the thiolation of iodobenzene with a broad scope of disulfides in the presence of zinc, the coupled products are obtained in excellent and in many cases nearly quantitative yields.
- Gómez-Benítez, Valente,Baldovino-Pantaleón, Oscar,Herrera-álvarez, Cesar,Toscano, Rubén A.,Morales-Morales, David
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p. 5059 - 5062
(2007/10/03)
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- Ionic liquid as catalyst and reaction medium: A simple, convenient and green procedure for the synthesis of thioethers, thioesters and dithianes using an inexpensive ionic liquid, [pmIm]Br
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An easily accessible and inexpensive room temperature ionic liquid, 1-pentyl-3-methylimidazolium bromide, [pmIm]Br efficiently catalyzes the reaction of alkyl halides or acyl halides with thiols without any solvent at room temperature leading to the synthesis of thioethers and thioesters in high yields. This reaction has also been extended for the preparation of dithianes and transthioetherification. The ionic liquid is recovered and recycled for subsequent runs.
- Ranu, Brindaban C.,Jana, Ranjan
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p. 1811 - 1818
(2007/10/03)
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- Pd2(dba)3/Xantphos-catalyzed cross-coupling of thiols and aryl bromides/triflates
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The cross-coupling of aliphatic and aromatic thiols and aryl bromides/triflates mediated by a Pd2(dba)3/Xantphos catalytic system in refluxing xylene (140°C) affords the corresponding aryl thioethers in good to excellent yields.
- Mispelaere-Canivet, Clotilde,Spindler, Jean-Francis,Perrio, Stéphane,Beslin, Pierre
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p. 5253 - 5259
(2007/10/03)
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- Indium(I) iodide-promoted cleavage of diaryl diselenides and disulfides and subsequent condensation with alkyl or acyl halides. One-pot efficient synthesis of diorganyl selenides, sulfides, selenoesters, and thioesters
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Diphenyl diselenides and disulfides undergo facile cleavages by indium(I) iodide and the corresponding generated selenate and thiolate anions condense in situ with alkyl or acyl halides present in the reaction mixture. Thus, a simple, efficient, and general procedure has been developed for the synthesis of unsymmetrical diorganyl selenides, sulfides (thioethers), selenoesters, and thioesters by this one-pot reaction at room temperature.
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 5793 - 5795
(2007/10/03)
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- Catalysis using phosphine oxide and sulfoxide compounds
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Phosphine oxide and sulfoxide compounds were used with transition metals, preferably palladium and nickel, to produce biaryls, arylthiols, arylphosphine oxides and arylamines via cross-coupling reactions with aryl halides and arylboronic acids, aryl Grignard reagents, thiols, phosphine oxides or amines.
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- Polymer-supported synthesis of heteroatom bidentate ligands for catalysis
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The invention relates to the combinatorial approaches to the preparation of novel polymer-supported heteroatom bidentate (PN, PO, PS) ligand libraries and the corresponding free compounds after cleavage from the supports. These compounds are useful as nov
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- The first phosphine oxide ligand precursors for transition metal catalyzed cross-coupling reactions: C-C, C-N, and C-S bond formation on unactivated aryl chlorides
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Rapid and regioselective oxidative addition of unactivated aryl chlorides in the presence of bases can be achieved by using metal complexes of phosphinous acid (RR′POH), for which air-stable phosphine oxides (RR′P(O)H) serve as ideal ligand precursors. Such processes can be incorporated into efficient catalytic cycles for a variety of C-C, C-N, and C-S bond-forming processes (see scheme, Ar = aryl).
- Li, George Y.
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p. 1513 - 1516
(2007/10/03)
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- Copper-mediated cross-coupling of aryl boronic acids and alkyl thiols
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matrix presented The cross-coupling of aryl boronic acids and alkanethiols mediated by copper(II) acetate and pyridine in anhydrous dimethylformamide affords aryl alkyl sulfides in good yield with a wide variety of substituted aryl boronic acids. The method is applicable to the synthesis of aryl sulfides of cysteine.
- Herradura, Prudencio S.,Pendola, Kathleen A.,Guy, R. Kiplin
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p. 2019 - 2022
(2007/10/03)
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- Preparation of thioethers using SN1-active halides and zinc mercaptides
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SN1-Active (tertiary alkyl, allylic and benzylic) halides react with zinc mercaptides, prepared in situ by contacting mercaptans with either zinc carbonate or zinc sulphide, under optimised conditions, to afford thioethers in moderate to very good yields (50-95 percent). The method is particularly useful for the preparation of thioethers with at least one bulky alkyl group.
- Srinivas, S.,Srinivas, P.,Gurudutt, K. N.
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p. 1174 - 1176
(2007/10/03)
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- Carbon-sulfur bond-forming reductive elimination involving sp-, sp2-, and sp3-hybridized carbon. Mechanism, steric effects, and electronic effects on sulfide formation
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Palladium thiolato complexes [(L)Pd(R)(SR')], within which L is a chelating ligand such as DPPE, DPPP, DPPBz, DPPF, or TRANSPHOS, R is a methyl, alkenyl, aryl, or alkynyl ligand, and R' is an aryl or alkyl group, were synthesized by substitution or proton-transfer reactions. All of these thiolato complexes were found to undergo carbon-sulfur bond-forming inductive elimination in high yields to form dialkyl sulfides, diaryl sulfides, alkyl aryl sulfides, alkyl alkenyl sulfides, and alkyl alkynyl sulfides. Reductive eliminations forming alkenyl alkyl sulfides and aryl alkyl sulfides were the fastest. Eliminations of alkynyl alkyl sulfides were slower, and elimination of dialkyl sulfide was the slowest. Thus the relative rates for sulfide elimination as a function of the hybridization of the palladium-bound carbon follow the trend sp2 > sp >> sp3. Rates of reductive elimination were faster for cis-chelating phosphine ligands with larger bite angles. Kinetic studies, along with results from radical trapping reactions, analysis of solvent effects; and analysis of complexes with chelating phosphines of varying rigidity, were conducted with [Pd(L)(S-tert-butyl)(Ar)] and [Pd(L)(S- tert-butyl)(Me)]. Carbon-sulfur bond-forming reductive eliminations involving both saturated and unsaturated hydrocarbyl groups proceed by an intramolecular, concerted mechanism. Systematic changes in the electronic properties of the thiolate and aryl groups showed that reductive elimination is the fastest for electron deficient aryl groups and electron rich arenethiolates, suggesting that the reaction follows a mechanism in which the thiolate acts as a nucleophile and the aryl group an electrophile. Studies with thiolate ligands and hydrocarbyl ligands of varying steric demands favor a migration mechanism involving coordination of the hydrocarbyl ligand in the transition state.
- Mann, Grace,Baranano, David,Hartwig, John F.,Rheingold, Arnold L.,Guzei, Ilia A.
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p. 9205 - 9219
(2007/10/03)
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- Palladium-Catalyzed Amination of Aryl Halides: Mechanism and Rational Catalyst Design
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Palladium complexes of tri-o-tolyl phosphine and bis(diphenylphospino)ferrocene catalyze the reaction between aryl halides and either tin amides or amines in the presence of base to form aryl amines by halide substitution. This account describes our mechanistic and synthetic studies related to the amination reactions. These studies include kinetic behavior of the catalytic systems as well as direct observation of the primary stoichiometric reactions comprising the catalysis - including the rare C-N bond-forming reductive eliminations - and the mechanisms of these individual reactions. This paper also describes the development of tin-free amide sources and second generation amination catalysts that have resulted from our mechanistic understanding of the amination chemistry.
- Hartwig, John F.
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p. 329 - 340
(2007/10/03)
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- The palladium-catalyzed cross-coupling reaction of 9-organothio-9-borabicyclo[3.3.1]nonanes with organic electrophiles: Synthesis of unsymmetrical sulfides
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The synthesis of unsymmetrical sulfides was carried out in high yields by the palladium-catalyzed cross-coupling reaction of 9-organothio-9-borabicyclo[3.3.1]nonane (9-RS-9-BBN) with organic electrophiles, such as iodoarenes, 1-iodo-1-alkenes, allyl carbonate and propargyl carbonate. Iodoarenes and 1-iodo-1-atkenes were smoothly converted into the corresponding sulfides at 50 °C in the presence of PdC12(dppf) (3 mol%) and K3PO4 (3 equiv.) in DMF. In contrast, the cross-coupling reaction of 9-RS-9-BBN with allyl or propargyl carbonates occurred in DMF without the assistance of a base. Both reactions catalyzed by Pd(dba)2-dppf regioselectively produced allyl and allenyl sulfides in excellent yields. The scope and limitations of the reactions, as well as the effects of varying the reaction conditions, are discussed.
- Ishiyama, Tatsuo,Mori, Masashi,Suzuki, Akira,Miyaura, Norio
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p. 225 - 231
(2007/10/03)
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- A reactivity study of [η6-(tert-butylsulfonyl)benzene]-tricarbonylchromium(0)
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Addition of nucleophiles [LiC(Me)2CN, LiCHS(CH2)3S, BrMgCH2CH=CH2, LiCH2CO2But] to tricarbonyl[η6-(tert-butylsulfonyl)benzene]chromium(0) 4 followed by iodi
- Gibson, Susan E.,Guillo, Nathalie,White, Andrew J. P.,Williams, David J.
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p. 2575 - 2581
(2007/10/03)
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- Preparation of t-butyl sulfides by a novel ligand-transfer reaction of aryl thiocyanates
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Aryl t-butyl sulfides are prepared in good to excellent yields by the reaction of aryl thiocyanates with (t-Bu)2Cu(CN)Li2.
- Toste, F. Dean,Still, Ian W. J.
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p. 4361 - 4364
(2007/10/02)
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- Novel reactions of perfluoroalkylphenyl sulfides with organolithium reagents
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The reaction of anisole with organolithium reagents, commonly known as ortho-directed metallation, is of considerable synthetic utility in organic chemistry and as such has attracted considerable attention in recent years.Over the past 50 years, several mechanisms have been proposed to account for the observed regioselective metallation.For the first time, the reaction of perfluoroalkylphenyl sulfides with organolithium reagents has been investigated and found to furnish products resulting from the replacement of the perfluoroalkyl moieties with alkyl groups derived from the metallating agents.Phenyltrifluoromethyl ether, the anisole analog, failed to undergo metallation.A rationalization for the formation of unusual products via mediation of a single-electron-transfer process is presented in this paper together with the spectral data of the products. - Keywords: Reactions; Perfluoroalkylphenyl sulfides; Organolithium reagents; NMR spectroscopy; Mass spectrometry; Orthometallation
- Munavalli, S.,Hassner, A.,Rossman, D. I.,Singh, S.,Rohrbaugh, D. K.,Ferguson, C. P.
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- Nickel-catalysed Substitutions of Aryl tert-Butyl Sulfones with Organometallic Reagents: Synthesis of ortho-Substituted Unsymmetrical Biaryls
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In the presence of a catalytic amount of a nickel salt, aryl tert-butyl sulfones react with aryl Grignard reagents to give biaryls.This reaction is used in conjunction with the powerful ortho-lithiation-directing ability of aryl tert-butyl sulfonyl groups to make unsymmetrical ortho-substituted biaryls.In certain cases, the substitution of an aryl alkylsulfonyl group by an organometallic reagent is possible without a transition metal catalyst.
- Clayden, Jonathan,Cooney, J. Jonathan A.,Julia, Marc
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- Alkylthio substituted tricarbonyl(η6-arene)chromium(0) complexes as substrates for asymmetric oxidation
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Oxidation of methylthio substituted tricarbonyl(η6-arene)chromium(0) complexes with Ti(OPr(i))4/ diethyl tartrate H2O/ cumene hydroperoxide (2:4:2:1.3) gives methylsulfinyl substituted tricarbonyl(η6-arene)chromium(0) complexes in 60-73% yield and 81-86% e.e. (29-60% yield and 90 ≥ 95% e.e. after crystallisation); diethyl tartrate gives higher optical and chemical yields than dimethyl or diisopropyl tartrates and the reaction conditions are ineffective for other alkylthio and arylthio substituents: diethyl L-(+)-tartrate and diethyl D-(-)-tartrate lead to complexes of R and S configuration respectively; although an attempted kinetic resolution of tricarbonyl[η6-(melhylsulfinyl)benzene] was unsuccessful, subjecting tricarbonyl[η6-1-melhyl-2-(methylthio)benzene]chromium(0) to kinetic resolution conditions led to the isolation of recovered starting material and the corresponding sulfinyl substituted complex with enantiomeric excesses of 59 and 60% respectively.
- Griffiths,Perrio,Thomas
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p. 1847 - 1864
(2007/10/02)
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- GENERATION OF CHALCOGENIDE ANIONS IN HYDRAZINE HYDRATE MEDIUM
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Aromatic thiols and dichalcogenides in hydrazine hydrate are effective generators of chalcogenide ions that will react with organyl halides to form diorganyl chalcogenides.Alkanethiols and dialkyl dichalcogenides are less effective in reaction with organyl chalcogenides.
- Turchaninova, L. P.,Korchevin, N. A.,Deryagina, E. N.,Trofimov, B. A.,Voronkov, M. G.
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p. 125 - 126
(2007/10/02)
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- Ortho-Metalated Aryl tert-Butyl Sulfones, Comparison with Other Directing Groups and New Methodology for Polysubstituted Aromatics
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The general utility of ortho-lithiated aryl tert-butyl sulfones for the synthesis of a variety of 2- and 2,6-carbon- and heteroatom-substituted products in good to excellent yields is described (Schemes I, VI, VII).
- Iwao, M.,Iihama, T.,Mahalanabis, K. K.,Perrier, H.,Snieckus, V.
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- Reactions of Alkylmercurials with Heteroatom-Centered Acceptor Radicals
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The relative reactivities of alkylmercury halides toward PhS., PhSe., or I. decrease drastically from R = tert-butyl to R = sec-alkyl to R = n-butyl, indicative that R. is formed in the rate-determining step in the attack of these radicals upon RHgCl.The alkyl radicals thus formed will enter into chain reactions in which a heteroatom-centered radical (A.) is regenerated from substrates such as RS-SR, ArSe-SeAr, ArTe-TeAr, PhSe-SO2Ar, Cl-SO2Ph; ZCH=CHA (A = Cl, I, SPh, SO2Ph); or PhCCHA (A = I, SPh, SO2Ph). β-Styrenyl (PhCH=CHA, Ph2C=CHA) and β-phenethynyl (PhCCA) systems with A = I, Br, SO2Ph also enter into chain reactions with mercury(II) salts with the ligands PhS, PhSe, PhSO2, or (EtO)2PO.The relative reactivities of a series of reagents toward t-Bu. and of PhCH=CHA, Ph2C=CHA, and PhCCA toward c-C6H11. are reported as well as the regioselectivity of t-Bu. attack observed for 1,2-disubstituted ethylenes (ZCH=CHA) with Z and A from the group Ph, Cl, Br, I, SO2Ph, SPh, Bu3Sn.Reactions of (E)- and (Z)-PhCH=CHI or MeO2CCH=CHI with t-Bu. or c-C6H11. occurred in a regioselective and stereospecific (retention) manner.Reactions of (E)- and (Z)-ClCH=CHCl occurred in a nonstereospecific manner in which the E/Z product ratio increased with the bulk of the attacking radical.A similar effect on the E/Z product ratios was observed for (Z)-MeO2CCH=CHCl.
- Russell, Glen A.,Ngoviwatchai, Preecha,Tashtoush, Hasan I.,Pla-Dalmau, Anna,Khanna, Rajive K.
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p. 3530 - 3538
(2007/10/02)
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- Radical Switch Reaction. A Novel Reaction between Two Free Radicals in a Solvent Cage
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Studies on the thermal decomposition of t-butyl phenylazo sulfone suggested the occurrence of a radical switch reaction, a novel type of reaction between two radicals.A primary geminate radical pair, t-butanesulfonyl and phenyl radical pair, exchange sulfur dioxide to form a new radical pair consisting of t-butyl and benzenesulfonyl radicals.The generation of benzenesulfonyl radical was confirmed by its ESR spectrum and the isolation of products containing a benzenesulfonyl group.
- Kobayashi, Michio,Gotoh, Michiko,Yoshida, Masato
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p. 295 - 300
(2007/10/02)
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- Lewis Acid-catalysed Nucleophilic Displacement of the Nitro Group from Nitroalkanes
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Reaction of trimethylsilyl phenyl sulphide with tertiary and benzyl nitro compounds in the presence of SnCl4 gives the corresponding sulphides.
- Ono, Noboru,Yanai, Tetsuya,Kaji, Aritsune
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p. 1040 - 1041
(2007/10/02)
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- Thioether complexes of tungsten hexacarbonyl
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The preparation of a series of organic and organometallic thioethers R3MSR' (M = C,Si,Ge, or Sn) is reported.From these, several new compounds of type 1 are synthesized, some of which contain para-substituted aryl functions for R and R'.In hexane solution in the carbonyl streching region of the ir the uv there is evidence for a degree of multiple bonding, at least in the M - S - WW - CO portion of these molecules.Multiple bonding extending into aromatic R or R'is small or non-existent and cannot be assessed precisely because of spontaneous decomposition of the complexes.All the complexes undergo a thermally initiated decomposition, the case of which depends on the nature of R, R', and M.The unusual W(I) thiolate cis-2 is the termal decomposition product.
- Lucas, C. Robert
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p. 1758 - 1763
(2007/10/02)
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- Nucleophilic Substitution of Alkyl Halides by Zinc Salts: Part 4-Synthesis of Thioethers and Thiolesters
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A variety of alkyl halides including tertiary alkyl halides react smoothly with the zinc salts of thiols and thiolcarboxylic acids yielding thioethers and thiolesters.
- Rajanikanth, B.,Ravindranath, B.
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p. 1043 - 1045
(2007/10/02)
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- THIOSULFONIC S-ESTERS-III. A CONVENIENT PREPARATION OF AROMATIC SULFIDES
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The nucleophilic attack of alkyl- and aryl-lithium compounds at the sulfenyl sulfur atom in thiosulfonic S-esters performs a convenient synthesis of aromatic sulfides which are obtained cleanly and in generally excellent yields.Considering that recently we have reported a ready preparation of thiosulfonic S-esters from sulfonyl chlorides, this sulfidation reaction completes an interesting general procedure for converting the laters to any symmetrical or unsymmetrical sulfides.
- Palumbo, Giovanni,Ferreri, Carla,D'Ambrosio, Clotilde,Caputo, Romualdo
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p. 235 - 238
(2007/10/02)
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