- Sulfonium Salts as Liquid-Liquid Phase-Transfer Catalysts
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Lauryldimethylsulfonium and tri(n-butyl)sulfonium salts serve as highly efficient catalysts for two-phase reactions.
- Kondo, Shuji,Takeda, Yuji,Tsuda, Kazuichi
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Read Online
- Triphenylsulfonium Salts as Effective Phase Transfer Catalysts under Alkaline Conditions
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Triphenylsulfonium salts work as effective phase transfer catalysts for nucleophilic substitution reactions on alkyl halides (e.g. 1) and addition reaction of dichlorocarbene to cyclohexene (8) under strongly alkaline conditions.
- Kondo, Shuji,Takeda, Yuji,Tsuda, Kazuichi
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Read Online
- Alkylation of Nitropyridines via Vicarious Nucleophilic Substitution
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Electrophilic nitropyridines react with sulfonyl-stabilized carbanions to give products of C-H alkylation via vicarious nucleophilic substitution. The process consists of formation of the Meisenheimer-type adduct followed by base-induced β-elimination of the sulfinic acid (e.g., PhSO2H). Mechanistic studies reveal that in the latter step alkyl substituent and adjacent nitro group tend to planarize for effective stabilization of benzyl anion, and thus, adduct of hindered isopropyl carbanion remains stable toward elimination for steric reasons.
- Antoniak, Damian,Barbasiewicz, Micha?
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supporting information
p. 516 - 519
(2022/01/20)
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- Facile Thiol–Ene Click Protocol Using Benzil as Sensitizer and White LED as Light Source
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The thiol–ene reaction leading to a series of thioether derivatives by simple metal and oxidant free visible light promoted photosensitized protocol, following anti-Markonikov hydrothiolation of unactivated aryl and alkyl olefins at room temperature is demonstrated. Benzil served as a green photosensitizer in this reaction and white LED lights as a light source. This radical based thiol–ene reaction is operationally simple and tolerates a wide variety of functional groups present in olefins.
- Das, Anupam,Thomas, K. R. Justin
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supporting information
p. 7214 - 7218
(2020/11/30)
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- A General Approach to Deboronative Radical Chain Reactions with Pinacol Alkylboronic Esters
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The generation of carbon-centered radicals from air-sensitive organoboron compounds through nucleohomolytic substitution at boron is a general method to generate non-functionalized and functionalized radicals. Due to their reduced Lewis acidity, alkylboronic pinacol esters are not suitable substrates. We report their in situ conversion into alkylboronic catechol esters by boron-transesterification with a substoichiometric amount of catechol methyl borate combined with an array of radical chain processes. This simple one-pot radical-chain deboronative method enables the conversion of pinacol boronic esters into iodides, bromides, chlorides, and thioethers. The process is also suitable the formation of nitriles and allylated compounds through C?C bond formation using sulfonyl radical traps. The power of combining radical and classical boron chemistry is illustrated with a modular 5-membered ring formation using a combination of three-component coupling and protodeboronative cyclization.
- André-Joyaux, Emy,Kuzovlev, Andrey,Renaud, Philippe,Tappin, Nicholas D. C.
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p. 13859 - 13864
(2020/06/10)
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- Nickel-Catalyzed Inter- and Intramolecular Aryl Thioether Metathesis by Reversible Arylation
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A nickel-catalyzed aryl thioether metathesis has been developed to access high-value thioethers. 1,2-Bis(dicyclohexylphosphino)ethane (dcype) is essential to promote this highly functional-group-tolerant reaction. Furthermore, synthetically challenging macrocycles could be obtained in good yield in an unusual example of ring-closing metathesis that does not involve alkene bonds. In-depth organometallic studies support a reversible Ni0/NiII pathway to product formation. Overall, this work not only provides a more sustainable alternative to previous catalytic systems based on Pd, but also presents new applications and mechanistic information that are highly relevant to the further development and application of unusual single-bond metathesis reactions.
- Delcaillau, Tristan,Bismuto, Alessandro,Lian, Zhong,Morandi, Bill
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supporting information
p. 2110 - 2114
(2019/12/24)
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- Alkyl Sulfides as Promising Sulfur Sources: Metal-Free Synthesis of Aryl Alkyl Sulfides and Dialkyl Sulfides by Transalkylation of Simple Sulfides with Alkyl Halides
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A site-selective metal-free dealkylative approach to synthesize aryl alkyl and symmetrical dialkyl sulfides has been developed. This procedure is convenient and has wide functional group tolerance giving rise to sulfides carrying various alkyl chains from simple alkyl sulfides and alkyl halides in good to excellent yields. This transalkylation proceeds by an ionic mechanism via sulfonium intermediates and it was proposed that dimethylacetamide (DMAC) may participate in part to promote the reaction.
- Liu, Ting,Qiu, Renhua,Zhu, Longzhi,Yin, Shuang-Feng,Au, Chak-Tong,Kambe, Nobuaki
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supporting information
p. 3833 - 3837
(2018/12/05)
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- The energy-transfer-enabled biocompatible disulfide–ene reaction
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Sulfur-containing molecules participate in many essential biological processes. Of utmost importance is the methylthioether moiety, present in the proteinogenic amino acid methionine and installed in tRNA by radical-S-adenosylmethionine methylthiotransferases. Although the thiol–ene reaction for carbon–sulfur bond formation has found widespread applications in materials or medicinal science, a biocompatible chemo- and regioselective hydrothiolation of unactivated alkenes and alkynes remains elusive. Here, we describe the design of a general chemoselective anti-Markovnikov hydroalkyl/aryl thiolation of alkenes and alkynes—also allowing the biologically important hydromethylthiolation—by triplet–triplet energy transfer activation of disulfides. This fast disulfide–ene reaction shows extraordinary functional group tolerance and biocompatibility. Transient absorption spectroscopy was used to study the sensitization process in detail. The hereby gained mechanistic insights were successfully employed for optimization of the catalytic system. This photosensitized transformation should stimulate bioimaging applications and carbon–sulfur bond-forming late-stage functionalization chemistry, especially in the context of metabolic labelling.
- Teders, Michael,Henkel, Christian,Anh?user, Lea,Strieth-Kalthoff, Felix,Gómez-Suárez, Adrián,Kleinmans, Roman,Kahnt, Axel,Rentmeister, Andrea,Guldi, Dirk,Glorius, Frank
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p. 981 - 988
(2018/08/31)
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- CATALYTIC C-X-BOND METATHESIS THROUGH ARYLATION
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The present invention refers to a process for a catalytic aryl transfer to rearrange the backbone of aromatic C-X bonds.
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Page/Page column 9; 18
(2018/09/28)
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- Metal–organic framework MOF-199-catalyzed direct and one-pot synthesis of thiols, sulfides and disulfides from aryl halides in wet polyethylene glycols (PEG 400)
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A highly porous metal–organic frame work Cu3 BTC2 (copper(II)-benzene-1,3,5-tricarboxylate) that is known as MOF-199 was synthesized from the reaction of 1,3,5-benzenetricarboxylic acid and Cu(OAc)2·H2O by a solvothermal method and characterized by several techniques including FT-IR, XRD, EDX and scanning electron microscopy. The MOF-199 used as an efficient catalyst for one-pot synthesis of thiols by domino reactions of aryl halides and thiourea, and subsequently conversion to aryl alkyl sulfides and diaryl disulfides in polyethylene glycols (PEGs). A variety of aryl alkyl sulfides can be obtained in good to excellent yields in a relatively short reaction time and in the presence of the trace amount of catalyst. Also, the catalyst can be separated from the reaction mixture by decanting, and be reused without significant degradation in catalytic activity.
- Soleiman-Beigi, Mohammad,Sadeghizadeh, Fatemeh,Basereh, Ali
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p. 572 - 583
(2017/09/27)
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- Scandium(III) Triflate-Catalyzed anti-Markovnikov Hydrothiolation of Functionalized Olefins
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Scandium(III) triflate promoted highly selective addition of thiols to functionalized olefins under mild conditions. The addition follows anti-Markovnikov regioselectivities, which are unusual for Lewis acids-catalyzed hydrothiolation. This reaction marks broad functional groups tolerance, which opens a beneficial synthetic route to functionalized and biologically active thio-compounds. This method is broadly applicable and offers a simple work-up in the green manner.
- Kuciski, Krzysztof,Pawluc, Piotr,Hreczycho, Grzegorz
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p. 3936 - 3942
(2016/01/25)
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- AROMATIC SULFIDE COMPOUNDS AND METHODS AND USE THEREOF
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Described herein, inter alia, are aromatic sulfide compositions and methods for treating or preventing cancer using the same.
- -
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Paragraph 0168; 0170
(2015/11/03)
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- Diaryl and heteroaryl sulfides: Synthesis via sulfenyl chlorides and evaluation as selective anti-breast-cancer agents
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A mild protocol for the synthesis of diaryl and heteroaryl sulfides is described. In a one-pot procedure, thiols are converted to sulfenyl chlorides and reacted with arylzinc reagents. This method tolerates functional groups including aryl fluorides and chlorides, ketones, as well as N-heterocycles including pyrimidines, imidazoles, tetrazoles, and oxadiazoles. Two compounds synthesized by this method exhibited selective activity against the MCF-7 breast cancer cell line in the micromolar range.
- Yonova, Ivelina M.,Osborne, Charlotte A.,Morrissette, Naomi S.,Jarvo, Elizabeth R.
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p. 1947 - 1953
(2014/04/03)
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- Transition-metal-free acid-mediated synthesis of aryl sulfides from thiols and thioethers
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The preparation of diaryl and alkyl aryl sulfides via acid-mediated coupling of thiols and thioethers with diaryliodonium salts is reported. The scope, limitations, and mechanism of the transformation are discussed.
- Wagner, Anna M.,Sanford, Melanie S.
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p. 2263 - 2267
(2014/04/03)
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- Amberlyst-15: An efficient heterogeneous reusable catalyst for selective anti-Markovnikov addition of thiols to alkenes/alkynes and for thiolysis of epoxides
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The anti-Markovnikov addition of thiols to alkenes/alkynes and thiolysis of epoxides is described using Amberlyst-15 as a selective, commercially available, inexpensive and reusable catalyst. The products like diorganyl sulphides, β-hydroxy sulphides and phenyl(styryl)sulfanes were obtained in good to excellent yields in short reaction time and with high regio-selectivity. The catalyst was reused up to five consecutive recycles without any loss in its catalytic activity. The developed methodology is a metal free protocol for C-S bond formation reaction with high atom economy.
- Lanke, Satish R.,Bhanage, Bhalchandra M.
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- Enantioselective nitrene transfer to sulfides catalyzed by a chiral iron complex
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Iron works: Enantioselective nitrene transfer to sulfide was accomplished by a chiral iron(III)/PyBOX catalyst (see scheme). Various sulfimides were thus obtained in high enantioselectivities and yields. Applications of this protocol to the syntheses of enantioenriched sulfoximines and an epoxide were also demonstrated. Copyright
- Wang, Jun,Frings, Marcus,Bolm, Carsten
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supporting information
p. 8661 - 8665
(2013/09/12)
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- Transition-metal-free O-,S -, and N-arylation of alcohols, thiols, amides, amines, and related heterocycles
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A new protocol for the Ullmann-type arylation process of different aromatic heterocycles without any transition-metal catalyst, implying the use of a combination of an excess of potassium hydroxide and dimethyl sulfoxide, is described. The reaction can be performed between a broad range of starting nucleophiles including phenol, alcohols, amines, nitrogen-containing five-membered systems such as pyrazoles, imidazoles, and indoles, and amides with haloarenes, iodide and bromide derivatives giving the best results, the possible pathway involving the in situ generation of the corresponding benzyne intermediate. When the reaction was performed with 2-iodoaniline and either carboxamides or isothiocyanato derivatives, the corresponding benzoazole derivatives were obtained.
- Cano, Rafael,Ramon, Diego J.,Yus, Miguel
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experimental part
p. 654 - 660
(2011/03/20)
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- Nano-CuFe2O4 as a magnetically separable and reusable catalyst for the synthesis of diaryl/aryl alkyl sulfides via cross-coupling process under ligand-free conditions
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An efficient protocol was developed for the CuFe2O4 nanopowder-catalyzed aryl-sulfur bond formation between aryl halide and thiol/disulfide. A variety of aryl sulfides were synthesized in impressive yields with good chemoselectivity and functional group tolerance in the presence of a catalytic amount of CuFe2O4, Cs2CO 3 as base, in nitrogen atmosphere, under ligand-free conditions, in DMSO as solvent at 100 °C. The catalyst is air-stable, inexpensive, magnetically separable and recyclable up to four cycles.
- Swapna, Kokkirala,Murthy, Sabbavarapu Narayana,Jyothi, Mocharla Tarani,Nageswar, Yadavalli Venkata Durga
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experimental part
p. 5989 - 5996
(2011/10/08)
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- Silica nanoparticles as a reusable catalyst: A straightforward route for the synthesis of thioethers, thioesters, vinyl thioethers and thio-Michael adducts under neutral reaction conditions
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A simple and straightforward route for the synthesis of thioethers, thioesters, vinyl thioethers and thio-Michael adducts has been demonstrated using silica nanoparticles (NPs) as a reusable catalyst via the 1,2-addition of thiols to alkenes, alkynes and alkyl/acyl halides, and the 1,4-addition of thiols to conjugated alkenes at room temperature.
- Banerjee, Subhash,Das, Jayanta,Alvarez, Richard P.,Santra, Swadeshmukul
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experimental part
p. 302 - 306
(2010/06/13)
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- Solvent-free anti-markovnikov addition of thiols to alkenes using anhydrous cerium(III) chloride as catalyst
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The anti-Markovnikov addition of thiols to alkenes using CeCl3 as catalyst is described. The products were obtained in good to excellent yields. The reaction occurred under solvent-free conditions at room temperature.
- Silveira, Claudio C.,Mendes, Samuel R.,Líbero, Francieli M.
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experimental part
p. 790 - 792
(2010/06/13)
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- Facile preparation of aryl sulfides using palladium catalysis under mild conditions
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A convenient method for C-S cross-coupling of aryl bromides with various thiols has been developed that involves the use of a 1,1′- bis(diphenylphosphino)ferrocene (DPPF)-ligated palladium complex with N,N-diisopropylethylamine (DIPEA) as the base. This coupling is tolerant of a wide range of functional groups, including hydroxy, amino, cyano, nitro, formyl, and carboxyl groups. Georg Thieme Verlag Stuttgart - New York.
- Okauchi, Tatsuo,Kuramoto, Kouji,Kitamura, Mitsuru
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scheme or table
p. 2891 - 2894
(2011/02/28)
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- Efficient ligand-free copper-catalyzed C-S cross-coupling of thiols with aryl iodides using KF/Al2O3 as base
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We report a mild, convenient, environmentally friendly, and ligand-free synthetic protocol for the cross-coupling reaction of aryl iodides and thiols using 10 mol % CuI with KF/Al2O3 as the base, in DMF at 110 °C. Using this protocol, we have shown that a variety of aryl sulfides can be synthesized in excellent yields from readily available iodides and thiols.
- Feng, Yi-Si,Li, Yuan-Yuan,Tang, Lin,Wu, Wei,Xu, Hua-Jian
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experimental part
p. 2489 - 2492
(2010/06/14)
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- Native silica nanoparticle catalyzed anti-Markovnikov addition of thiols to inactivated alkenes and alkynes: a new route to linear and vinyl thioethers
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A new route for the synthesis of linear and vinyl thioethers has been demonstrated using bare silica nanoparticle as catalyst at room temperature under solvent-free conditions. The catalyst can be reused up to six times without loss of catalytic activity.
- Banerjee, Subhash,Das, Jayanta,Santra, Swadeshmukul
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scheme or table
p. 124 - 127
(2009/04/14)
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- A general, efficient, and functional-group-tolerant catalyst system for the palladium-catalyzed thioetherification of aryl bromides and iodides
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The cross-coupling reaction of aryl bromides and iodides with aliphatic and aromatic thiols catalyzed by palladium complexes of the bisphosphine ligand CyPF-tBu (1) is reported. Reactions occur in excellent yields, broad scope, high tolerance of functional groups, and with turnover numbers that exceed those of previous catalysts by 2 or 3 orders of magnitude. These couplings of bromo- and iodoarenes are more efficient than the corresponding reactions of chloroarenes and could be conducted with less catalyst loading and/or milder reaction conditions. Consequently, limitations regarding scope and functional group tolerance previously reported in the coupling of aryl chlorides are now overcome.
- Fernandez-Rodriguez, Manuel A.,Hartwig, John F.
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experimental part
p. 1664 - 1672
(2009/07/17)
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- Efficient C-S cross coupling catalyzed by Cu2O
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A protocol for the copper-catalyzed C-S bond formation between aryl, alkyl, or heteroaryl thiols and aryl or heteroaryl halides is reported. The reaction is catalyzed by Cu2O which shows the highest catalytic activity with ethyl 2-oxocyclohexanecarboxylate ligand in DMSO at 80 °C. The corresponding coupling products are obtained with good to excellent yields under relatively mild reaction conditions with good chemoselectivity and functional group tolerance.
- Xu, Hua-Jian,Zhao, Xiao-Yang,Deng, Jin,Fu, Yao,Feng, Yi-Si
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experimental part
p. 434 - 437
(2009/05/11)
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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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- Synthesis of aryl sulfides by decarboxylative C-S cross-couplings
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A study was conducted to demonstrate the transition-metal-catalyzed synthesis of aryl sulfides by decarboxylative C-S cross-couplings. Coupling reaction of 2-nitrobenzoic acid with 1-octanethiol were carried in the presence of different combinations of tr
- Duan, Zhongyu,Ranjit, Sadananda,Zhang, Pengfei,Liu, Xiaogang
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supporting information; experimental part
p. 3666 - 3669
(2009/12/07)
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- Ligand-free C-S bond formation catalyzed by copper(I) oxide
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An efficient ligand-free Cu2O-catalyzed C-S bond-formation reaction was developed. A large number of diaryl sulfides and alkylaryl sulfides could be rapidly assembled using this new reaction protocol. Georg Thieme Verlag Stuttgart.
- Xu, Hua-Jian,Zhao, Xiao-Yang,Fu, Yao,Feng, Yi-Si
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experimental part
p. 3063 - 3067
(2009/07/04)
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- Conversion of (sp3)C-F bonds of alkyl fluorides to (sp 3)C-heteroatom (heteroatom = I, SR, SeR, TeR) bonds by the use of magnesium reagents having heteroatom substituents
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A convenient method for conversion of (sp3)C-F bonds to (sp 3)C-Z (Z = I, SR, SeR, TeR) bonds has been developed. The reaction proceeds at room temperature using magnesium salts (Z-MgX). SN2 mechanism for substitiution of primary alkyl fluorides with MgI2 in ether was supported by the inversion of the stereochemistry of the carbon connecting to F. Copyright
- Begum, Shameem Ara,Terao, Jun,Kambe, Nobuaki
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p. 196 - 197
(2008/02/03)
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- CATALYSTS FOR ARYL SULFIDE SYNTHESIS AND METHOD OF PRODUCING ARYL SULFIDES
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The present invention relates to the formation of aryl sulfides and aryl thiols from aryl halides and thiols, thiolates or thiolate equivalents. The present invention provides a catalyst for the coupling of aryl halides with alkyl or aryl thiols or a hydrogen sulfide equivalent to form aryl alkyl, aryl silyl or diaryl sulfides. The reaction encompasses bromoarenes and other similar compounds containing leaving groups as well as nitrile, ester, keto, free hydroxyl, free amino, free carboxylic acid and other common functionalities. The invention can be used to prepare pharmaceutical compounds, especially including their intermediates, agricultural agents and aryl sulfide polymers.
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Page/Page column 20; 32; 33
(2008/06/13)
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- Efficient CuO-nanoparticle-catalyzed C-S cross-coupling of thiols with iodobenzene
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Cheap but good: Readily available CuO nanoparticles are not only less expensive than other catalysts used for the C-S cross-coupling of thiols with aryl halides, but they are also effective at a moderate temperature and low concentration. The title reaction proceeds with a variety of alkyl and aryl thiols to give the corresponding sulfides in high yields (see scheme).
- Rout, Laxmidhar,Sen, Tamal K.,Punniyamurthy, Tharmalingam
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p. 5583 - 5586
(2008/03/18)
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- Conversion of a (sp3)C-F bond of alkyl fluorides to (sp 3)C-X (X = Cl, C, H, O, S, Se, Te, N) bonds using organoaluminium reagents
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A simple method for the conversion of (sp3)C-F bonds of alkyl fluorides to (sp3)C-X (X = Cl, C, H, O, S, Se, Te, N) bonds has been achieved by the use of a hexane solution of organoaluminum reagents having Al-X bonds. The Royal Society of Chemistry.
- Terao, Jun,Begum, Shameem Ara,Shinohara, Yoshiaki,Tomita, Masahiro,Naitoh, Yoshitaka,Kambe, Nobuaki
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p. 855 - 857
(2007/10/03)
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- Highly efficient and functional-group-tolerant catalysts for the palladium-catalyzed coupling of aryl chlorides with thiols
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The cross-coupling reaction of aryl chlorides with aliphatic and aromatic thiols catalyzed by palladium complexes of the strongly binding bisphosphine CyPF-tBu ligand (1) is reported. Most of the reactions catalyzed by complexes of ligand 1 occur with turnover numbers that exceed those of previous catalysts by two orders of magnitude. The reactions occur with excellent yields, broad scope and high tolerance of functional groups. Coupling of aryl halides with thiols in the presence of low loadings of catalysts derived from other Josiphos type ligands, as well as ligands of other structural types, are also described.
- Fernandez-Rodriguez, Manuel A.,Shen, Qilong,Hartwig, John F.
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p. 7782 - 7796
(2007/10/03)
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- A general and long-lived catalyst for the palladium-catalyzed coupling of aryl halides with thiols
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A general catalytic system for the coupling of aryl halides and sulfonates with thiols based on the use of the CyPF-t-Bu ligand (1) is reported. The reactions catalyzed by complexes of 1 occur in excellent yields with broad scope and exhibit extraordinary turnover numbers and high tolerance of functional groups. Turnover numbers usually exceed those of previous catalysts by 2 or 3 orders of magnitude. In addition, the reactions of aryl tosylates with alkane thiols to form aryl sulfides are reported for the first time. Finally, the synthesis of a diarylsulfide from two bromoarenes was accomplished using a hydrogen sulfide surrogate. Copyright
- Fernandez-Rodriguez, Manuel A.,Shen, Qilong,Hartwig, John F.
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p. 2180 - 2181
(2007/10/03)
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- The reaction between diphenyliodonium iodide and disulfides in the presence of a Zn/AlCl3 system: A convenient method for the synthesis of organic sulfides
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A convenient method for the synthesis of alkyl aryl- and diaryl sulfides by the reaction of diphenyliodonium iodide and disulfides in the presence of Zn/AlCl3 system in acetonitrile is reported. Copyright Taylor & Francis Inc.
- Movassagh, Barahman,Mossadegh, Amir
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p. 2275 - 2278
(2007/10/03)
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- CuI-catalyzed coupling reactions of aryl iodides and bromides with thiols promoted by amino acid ligands
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Novel mild conditions for the CuI-catalyzed coupling reactions of aryl iodides and bromides with aliphatic and aromatic thiols using amino acids as the ligand are reported.
- Deng, Wei,Zou, Yan,Wang, Ye-Feng,Liu, Lei,Guo, Qing-Xiang
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p. 1254 - 1258
(2007/10/03)
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- Nickel-catalyzed cross-coupling between functionalized primary or secondary alkylzinc halides and primary alkyl halides
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In the presence of Bu4NI (3 equiv) and 4-fluorostyrene (20 mol %), unreactive primary and secondary alkylzinc iodides undergo nickel-catalyzed cross-couplings with various primary alkyl iodides or bromides. More reactive secondary dialkylzincs and the mixed zinc organometallics RZnTMSM undergo the cross-coupling reaction in the absence of Bu4NI. The bicyclic secondary diorganozinc 6 prepared via boron-zinc exchange reacts with high retention of configuration. Free NH-groups are tolerated in the cross-coupling allowing the synthesis of aminated products.
- Jensen, Anne Eeg,Knochel, Paul
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- Alkyl- and Arylthiodediazoniations of Dry Arenediazonium o-Benzenedisulfonimides. Efficient and Safe Modifications of the Stadler and Ziegler Reactions to Prepare Alkyl Aryl and Diaryl Sulfides
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The reaction between dry arenediazonium o-benzenedisulfonimides 1 and sodium thiolates in anhydrous methanol represents an efficient and safe procedure, of general validity, for the preparation of unfunctionalized or variously functionalized alkyl aryl and diaryl sulfides. As a rule, the reaction temperature was maintained at 0-5°C for the alkylthiodediazoniations and at room temperature (20-25°C) for the arylthiodediazoniations. The sulfide yields are generally high; of the 63 considered examples, 43 gave yields greater than 80% and 13 were between 70% and 80%. Lower yields were obtained only when sterically hindered diazonium salts or thiols were used. A good amount of the o-benzenedisulfonimide (8) was always recovered from the reactions and could be reused to prepare salts 1. The copious experimental data collected in homogeneous conditions have offered several starting points for the study of the mechanism of these reactions.
- Barbero, Margherita,Degani, Iacopo,Diulgheroff, Nicola,Dughera, Stefano,Fochi, Rita,Migliaccio, Mara
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p. 5600 - 5608
(2007/10/03)
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- Chemoselective deoxygenation of sulfoxides with titanium tetraiodide
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Chemoselective deoxygenation of sulfoxides was carried out using TiI4 as a reducing agent to give sulfides in good to excellent yields.
- Shimizu,Shibuya,Hayakawa
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p. 1437 - 1438
(2007/10/03)
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- Anti-Markovnikov addition of thiols across double bonds catalyzed by H- Rho-zeolite
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A variety of olefins react with thiols in the presence of a catalytic amount of H-Rho-zeolite to afford the corresponding anti-Markovnikov addition products in good to excellent yields.
- Kumar, Pradeep,Pandey, Rajesh Kumar,Hegde, Vishnumurthy R.
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p. 1921 - 1922
(2007/10/03)
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- New efficient nickel-catalyzed cross-coupling reaction between two Csp3 centers
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The presence of a remote unsaturation (double bond, carbonyl group, cyano group) in an alkyl halide facilitates its cross-coupling reaction with various diorganozincs in the presence of Ni(acac)2 (7.5-10 mol % in THF/NMP mixtures). These results were used to develop a new general cross-coupling reaction between functionalized diorganozincs and alkyl iodides using m- or p-trifluoromethylstyrene as a reaction promotor and Ni(acac)2 as a catalyst (7.5-10 mol %; -35 °C, 5-10 h) leading to a broad range of polyfunctional cross-coupling products.
- Giovannini,Strudemann,Devasagayaraj,Dussin,Knochel
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p. 3544 - 3553
(2007/10/03)
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- Electrophile induced rearrangement of 1-alkynylaluminium ate complexes
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The title species have been shown to rearrange under the influence of the electrophile PhSCl to give tetrasubstituted vinylaluminium compounds protonolysis of which led to the corresponding vinyl sulfides in a highly stereoselective manner.
- Debuigne, Antoine,Gerard, Julien,Hevesi, Laszlo
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p. 5943 - 5944
(2007/10/03)
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- An efficient nickel-catalyzed cross-coupling between sp3 carbon centers
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Since the pioneering work of Wurtz, cross-couplings between sp3 carbon centers have had the reputation of being difficult. In the presence of a catalytic amount of m-trifluoromethylstyrene, an efficient cross-coupling reaction takes place between polyfunctional primary alkyl iodides and diorganozinc compounds [Eq. (a)] to give a general catalytic cross-coupling between sp3 carbon centers. Piv = pivaloyl; Pent = pentyl; acac = acetalacetonate; NMP = N-methylpyrrolidone.
- Giovannini, Riccardo,Stüdemann, Thomas,Dussin, Gaelle,Knochel, Paul
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p. 2387 - 2390
(2007/10/03)
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- Allylation Using Allylborates
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A study has been carried out on the scope of allylation of a range of acetals activated by trimethylsilyl trifluoromethanesulfonate (TMSOTf) using a number of organoborates.Intermolecular allylation of acyclic acetals proceeds smoothly and in high yield using lithium n-butyltriallylborate or lithium methyltriallylborate in THF at -78 deg C while 1,3-dioxanes and dioxolanes give rise to some reduction products.Intramolecular allylation may be carried out via anchoring the triallylborane using an alkoxide anion.Mechanistic studies indicate that allyl transfer is from boron and not silicon, while stereoselectivity studies on the crotylation of acyclic acetals as well as the allylation of chiral acetals derived from (2R,4R)-pentanediol indicate moderate levels of diastereoselection.
- Hunter, Roger,Michael, Joseph P.,Tomlinson, Geoffrey D.
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p. 871 - 888
(2007/10/02)
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- Rate Constants for Chalcogen Group Transfers in Bimolecular Substitution Reactions with Primary Alkyl Radicals
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Rate constants for group transfers of the MeS, PhS, PhSe, and PhTe groups from chalcogen-substituted acetate, acetonitrile, malonate, and malononitrile compounds, from N-(phenylthio)phthalimide and from Me2S2 and Ph2S2 to primary alkyl radicals, have been determined by competition kinetics using PTOC esters as the radical precursors and competing trapping agents.Thio group transfers from malononitrile derivatives are marginally faster than the corresponding group transfer from the symmetrical disulfide, and the rate constant for PhSe group transfer from PhSeSePh isgreater than those from the derivatives studied here.Substituent effects suggest that the chalcogen transfer reactions may be concerted.For three cases in which direct comparisons can be made, the rate constants for reactions of phenylchalcogenides are approximately equal to those for halogen atom transfer when the chalcogen and halide are in the same row of the periodic table and the radical resulting from displacement is the same.The rate constants reported in this work will be useful for the rational design of synthetic schemes based on homolytic group transfer chemistry.
- Curran, Dennis P.,Martin-Esker, Amanda A.,Ko, Sung-Bo,Newcomb, Martin
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p. 4691 - 4695
(2007/10/02)
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- Chemical Reactions in Microemulsions: Application of Microemulsions as Solvents for Organic Synthesis
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In this paper, microemulsions are studied as media for reactions between reactants of very different solubility.In particular, the reaction of 1-bromooctane with iodide is dealt with as a model reaction.The phase behaviour of the microemulsion changes when the reactants are added and the progress of the reaction changes the concentration of the species involved.A number of standard reactions were also performed in microemulsions, for example nucleophilic substitutions, hydrolysis of esters, oxidation of an alcohol, reduction of an aldehyde, and reactions of active methylene compounds.A comparison of different solvents is done on the basis of the rate constants of three different reactions carried out in a microemulsion, in ethanol, in DMF and by phase-transfer catalysis.
- Schomaecker, Reinhard
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p. 810 - 833
(2007/10/02)
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- SYNTHESIS OF SUBSTITUTED TRANS-1,6-DIMETHYLBICYCLONON-2-ENES USING A CLAISEN REARRANGEMENT OF α-(THIOALKOXY)ESTERS
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The Claisen rearrangement of α-(thioalkoxy)esters provided access to substituted trans-1,6-dimethylbicyclonon-2-enes characteristic of the CD rings of the cucurbitanes.
- Richardson, Stewart K.,Sabol, Mark R.,Watt, David S.
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p. 359 - 368
(2007/10/02)
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- SPECIFIC HYDRATION AND NUCLEOPHILIC REACTIVITY OF ORGANIC ANIONS UNDER PHASE-TRANSFER CATALYSIS AND HOMOGENEOUS CONDITIONS
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The effect of specific hydration on the nucleophilic reactivity of the organic anions 3a-i has been studied under PhCl-aqueous NaOH (15-50percent) PTC conditions and in anhydrous chlorobenzene.The sensitivity to the specific solvation, in the order oxanion > carbanion >/= nitranion >/= thianion, can be explained on the basis of the different donor atom tendency.The data provide a useful guide to the choice of the best reaction conditions of these anions under PTC.
- Landini, Dario,Maia, Angelamaria,Rampoldi, Alessandro
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p. 513 - 518
(2007/10/02)
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- STUDIES ON CYCLOPHOSPHAZENES. II. SYNTHESIS AND CATALYTIC ACTIVITY OF NEW TYPES OF HEXA-SUBSTITUTED CYCLOPHOSPHAZENIC PODANDS
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The reaction between hexakis(p-hydroxybenzyloxy)cyclophosphazene 3 and polyethylene glycol monoalkyl ether tosylate leads to the formation of new types of hexakiscyclophosphazenes.The properties of these derivatives, including their catalytic activity under phase-transfer conditions, have been investigated.
- Podda, Gianni
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p. 397 - 400
(2007/10/02)
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