- Clean protocol for deoxygenation of epoxides to alkenes: Via catalytic hydrogenation using gold
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The epoxidation of olefin as a strategy to protect carbon-carbon double bonds is a well-known procedure in organic synthesis, however the reverse reaction, deprotection/deoxygenation of epoxides is much less developed, despite its potential utility for the synthesis of substituted olefins. Here, we disclose a clean protocol for the selective deprotection of epoxides, by combining commercially available organophosphorus ligands and gold nanoparticles (Au NP). Besides being successfully applied in the deoxygenation of epoxides, the discovered catalytic system also enables the selective reduction N-oxides and sulfoxides using molecular hydrogen as reductant. The Au NP catalyst combined with triethylphosphite P(OEt)3 is remarkably more reactive than solely Au NPs. The method is not only a complementary Au-catalyzed reductive reaction under mild conditions, but also an effective procedure for selective reductions of a wide range of valuable molecules that would be either synthetically inconvenient or even difficult to access by alternative synthetic protocols or by using classical transition metal catalysts. This journal is
- Fiorio, Jhonatan L.,Rossi, Liane M.
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p. 312 - 318
(2021/01/29)
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- N-bromosuccinimide/HCl mediated reduction of sulfoxides to sulfides
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An efficient reduction of sulfoxides to sulfides mediated by N-bromosuccinimide (NBS)/HCl system has been developed. This protocol shows good functional group compatibility as well as broad substrates scope with operational simplicity.
- Wang, Jianqiang,Shi, Fangmin,Dai, Dongyan,Xiong, Liping,Yang, Yongpo
-
supporting information
p. 439 - 443
(2021/02/03)
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- Catalytic dehydrogenation of amines to imines and the in-situ reduction of sulfoxides into sulfides
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The catalytic acceptorless dehydrogenation of primary amines into imines and H2 represents one of the most important organic transformations, and the in-situ utilization of the generated H2 for chemical reduction reactions has never
- Li, Bo,Liu, Bing,Liu, Xixi,Wang, Wei,Wang, Yanxin,Xiang, Nian,Zhang, Zehui
-
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- Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
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We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
- Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
-
supporting information
p. 3723 - 3728
(2021/04/07)
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- Synthesis of Aryl Methyl Sulfides from Arysulfonyl Chlorides with Dimethyl Carbonate as the Solvent and C1 Source
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A new procedure for the synthesis of aryl methyl sulfides from dimethyl carbonate (DMC) and arylsulfonyl chlorides has been achieved. In this strategy, DMC plays a dual role as both, C1 building block and green solvent. Arylsulfonyl chlorides served as the sulfur precursors, and a variety of aryl methyl sulfides were obtained in moderate to excellent yields with good functional group tolerance. Additionally, alkylsulfonyl chloride and dibenzyl carbonate are proven to be suitable substrates as well.
- Miao, Ren-Guan,Qi, Xinxin,Wu, Xiao-Feng
-
supporting information
p. 5219 - 5221
(2021/10/19)
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- Copper-Catalyzed Methylthiolation of Aryl Iodides and Bromides with Dimethyl Disulfide in Water
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An efficient route to aryl methyl sulfides through the copper-catalyzed coupling reaction of aryl iodides or bromides with dimethyl disulfide in water is described. Electron-donating and electron-withdrawing functional groups in the substrates were tolerated, and the corresponding products were obtained in moderate to good yields.
- Wang, Ying-Yu,Wu, Xiang-Mei,Yang, Ming-Hua
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supporting information
(2020/07/20)
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- Photocatalytic Deoxygenation of Sulfoxides Using Visible Light: Mechanistic Investigations and Synthetic Applications
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The photocatalytic deoxygenation of sulfoxides to generate sulfides facilitated by either Ir[(dF(CF3)ppy)2(dtbbpy)]PF6 or fac-Ir(ppy)3 is reported. Mechanistic studies indicate that a radical chain mechanism operates, which proceeds via a phosphoranyl radical generated from a radical/polar crossover process. Initiation of the radical chain was found to proceed via two opposing photocatalytic quenching mechanisms, offering complementary reactivity. The mild nature of the radical deoxygenation process enables the reduction of a wide range of functionalized sulfoxides, including those containing acid-sensitive groups, in typically high isolated yields.
- Clarke, Aimee K.,Parkin, Alison,Rossi-Ashton, James A.,Taylor, Richard J. K.,Unsworth, William P.
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p. 5814 - 5820
(2020/07/21)
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- Nickel phosphide nanoalloy catalyst for the selective deoxygenation of sulfoxides to sulfides under ambient H2pressure
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Exploring novel catalysis by less common, metal-non-metal nanoalloys is of great interest in organic synthesis. We herein report a titanium-dioxide-supported nickel phosphide nanoalloy (nano-Ni2P/TiO2) that exhibits high catalytic activity for the deoxygenation of sulfoxides. nano-Ni2P/TiO2 deoxygenated various sulfoxides to sulfides under 1 bar of H2, representing the first non-noble metal catalyst for sulfoxide deoxygenation under ambient H2 pressure. Spectroscopic analyses revealed that this high activity is due to cooperative catalysis by nano-Ni2P and TiO2. This journal is
- Fujita, Shu,Mitsudome, Takato,Mizugaki, Tomoo,Yamaguchi, Sho,Yamasaki, Jun,Yamazoe, Seiji
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supporting information
p. 8827 - 8833
(2020/11/23)
-
- Discovery and application of methionine sulfoxide reductase B for preparation of (S)-sulfoxides through kinetic resolution
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Here we report a methionine sulfoxide reductase B (MsrB) enzymatic system for the preparation of (S)-sulfoxides through kinetic resolution of racemic (rac) sulfoxides. Eight MsrB homologue recombinant proteins were expressed and their activities on asymmetric reduction of rac-sulfoxides were analyzed. Among these MsrB homologue proteins, one protein from Acidovorax species showed good activity and enantioselectivity towards several aryl-alkyl sulfoxides. The (S)-sulfoxides were prepared with 93–98% enantiomeric excess through kinetic resolution at initial substrate concentration up to 50 mM. The establishment of MsrB catalytic kinetic resolution system provides a new efficient green strategy for preparation of (S)-sulfoxides.
- Wen, Yuanmei,Peng, Liaotian,Zhou, Yang,Peng, Tao,Chen, Yu,Cheng, Xiaoling,Chen, Yongzheng,Yang, Jiawei
-
-
- A Manganese N-Heterocyclic Carbene Catalyst for Reduction of Sulfoxides with Silanes
-
The first reduction of sulfoxides catalysed by a well-defined manganese complex is described. A variety of sulfoxides are reduced to the corresponding sulfides in high yields using phenylsilane, diphenylsilane, and the economically feasible 1,1,3,3-tetramethyldisiloxane (TMDS) as reducing agents in the presence of a Mn-NHC complex. The reaction is performed under air and without the need of any additive. The involvement of radicals in the catalytic reaction is probed by spin-trap experiments.
- Sousa, Sara C. A.,Carrasco, Carlos J.,Pinto, Mara F.,Royo, Beatriz
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p. 3839 - 3843
(2019/06/24)
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- Nanolayered cobalt-molybdenum sulphides (Co-Mo-S) catalyse borrowing hydrogen C-S bond formation reactions of thiols or H2S with alcohols
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Nanolayered cobalt-molybdenum sulphide (Co-Mo-S) materials have been established as excellent catalysts for C-S bond construction. These catalysts allow for the preparation of a broad range of thioethers in good to excellent yields from structurally diverse thiols and readily available primary as well as secondary alcohols. Chemoselectivity in the presence of sensitive groups such as double bonds, nitriles, carboxylic esters and halogens has been demonstrated. It is also shown that the reaction takes place through a hydrogen-autotransfer (borrowing hydrogen) mechanism that involves Co-Mo-S-mediated dehydrogenation and hydrogenation reactions. A novel catalytic protocol based on the thioetherification of alcohols with hydrogen sulphide (H2S) to furnish symmetrical thioethers has also been developed using these earth-abundant metal-based sulphide catalysts.
- Corma, Avelino,Sorribes, Iván
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p. 3130 - 3142
(2019/03/13)
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- Preparation method of 4-methylsulfonyl benzaldehyde
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The invention discloses a preparation method of 4-methylsulfonyl benzaldehyde. The preparation method of the 4-methylsulfonyl benzaldehyde comprises the following steps: firstly, performing a reactionrepresented by a formula shown in the description on a compound 2 and sodium thiomethoxide in a solvent under the protection of an inert gas and action of a catalyst, mixing the obtained product andwater, performing an oxidation reaction under action of a catalyst, performing crystallization on the product in water, and performing filtration to obtain the target product 4-methylsulfonyl benzaldehyde. The method provided by the invention has simple and short steps, and the raw materials have a low price; the high efficiency heat mass transfer characteristic of a fixed bed reactor is utilized,so that the method is significantly distinguished from a current kettle-type synthetic process; and the high catalytic activity of the catalyst makes 4-(methylmercapto)toluene completely converted, the catalyst can be recycled and reused, the production process is green and environmentally friendly, emission of three waste (waste water, waste gas and solid waste) can be reduce, and the method ismore suitable for industrial production.
- -
-
Paragraph 0023-0025
(2019/07/29)
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- Transition-Metal-Free Aryl-Heteroatom Bond Formation via C-S Bond Cleavage
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Aryl-heteroatom bonds (C-Het) are almost ubiquitously present in chemical molecules. However, methods for diverse C-Het bond formations from a simple substrate are limited. Herein, we report a convenient and efficient C-S bond transformation of aryl sulfoniums to various C-Het bonds (C-O, C-S, C-Sn, C-Si, C-Se) in the absence of any transition-metal catalyst. These reactions proceeded in mild conditions with a wide substrate scope.
- Zhao, Jian-Nan,Kayumov, Muzaffar,Wang, Dong-Yu,Zhang, Ao
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supporting information
p. 7303 - 7306
(2019/10/02)
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- Reduction of CO2 with NaBH4/I2 for the Conversion of Thiophenols to Aryl Methyl Sulfides
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We report a tandem reaction to realize reduction of carbon dioxide with thiophenols to generate aryl methyl sulfides under the NaBH4/I2 system with 18-crown-6 as the solvent. Thiophenols bearing electron-donating and electron-withdrawing groups are feasible in this reaction. Controlled experiment results indicate that 18-crown-6 plays a critical role in six-electron reduction of carbon dioxide.
- Zhang, Bo,Fan, Zhengning,Guo, Zhiqiang,Xi, Chanjuan
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p. 8661 - 8667
(2019/07/03)
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- α-Methylation of 2-Arylacetonitrile by a Trimethylamine-Borane/CO2 System
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A highly selective monomethylation of 2-arylacetonitrile using CO2 is described. The utilization of trimethylamine-borane facilitates the six-electron reduction of CO2. This reaction is the first selective six-electron reductive functionalization of CO2 faciliated by C(sp3)-H bonds. A variety of 2-arylpropionitrile was obtained in good yields. The reaction could also be applied at the gram scale.
- Zhang, Xiaowei,Wang, Sheng,Xi, Chanjuan
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p. 9744 - 9749
(2019/08/16)
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- Palladium-Catalyzed Alkoxycarbonylation of Arylsulfoniums
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Alkoxycarbonylation of arylsulfoniums has been developed with the aid of a catalytic amount of a palladium-Xantphos complex under an atmospheric pressure of CO gas. Various functional groups such as carbonyl, cyano, halo, and sulfonyl groups were well tolerated under the present catalysis. Since aryldimethylsulfoniums were readily prepared from the corresponding aryl methyl sulfides and methyl triflate, one-pot alkoxycarbonylation of aryl methyl sulfides could be accomplished.
- Minami, Hiroko,Nogi, Keisuke,Yorimitsu, Hideki
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supporting information
p. 2518 - 2522
(2019/04/17)
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- Visible light-promoted formation of C-B and C-S bonds under metal- A nd photocatalyst-free conditions
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A green, efficient, photoinduced synthesis of arylboronic esters and aryl sulfides has been developed. Bench stable arylazo sulfones were used as radical precursors for a photocatalyst- A nd additive-free carbon-heteroatom bond formation under visible light. The protocols are applicable to a wide range of substrates, providing products in good yields.
- Blank, Lena,Fagnoni, Maurizio,Protti, Stefano,Rueping, Magnus
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p. 1243 - 1252
(2019/02/26)
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- Identification of MsrA homologues for the preparation of (R)-sulfoxides at high substrate concentrations
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Here we report a methionine sulfoxide reductase A (MsrA) homologue with extremely high substrate tolerance and a wide substrate scope for the biocatalytic preparation of enantiopure sulfoxides. This MsrA homologue which was obtained from Pseudomonas alcaliphila (named paMsrA) showed good activity and enantioselectivity towards a series of aryl methyl/ethyl sulfoxides 1a-1k, with electron-withdrawing or electron-donating substituents at the aromatic ring. Chiral sulfoxides in the R configuration were prepared with approximately 50% of yield and up to 99% enantiomeric excess through the asymmetric reductive resolution of racemic sulfoxide catalyzed by the recombinant paMsrA protein. More importantly, kinetic resolution has been successfully accomplished with high enantioselectivity (E > 200) at initial substrate concentrations up to 320 mM (approximately 45 g L-1), which represents a great improvement in the aspect of the substrate concentration for the biocatalytic preparation of chiral sulfoxides.
- Yang, Jiawei,Wen, Yuanmei,Peng, Liaotian,Chan, Yu,Cheng, Xiaoling,Chen, Yongzheng
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p. 3381 - 3388
(2019/04/01)
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- Efficient and selective hydrogenation of C-O bonds with a simple sodium formate catalyzed by nickel
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A Ni-catalyzed hydrogenation of C-O compounds with sodium formate is developed. Various esters, i.e. aryl, alkenyl, benzyl pivalates, and even the aryl ethers, were efficiently reduced with a loading of nickel catalysts down to 0.5 mol%. Reactive functional groups such as C-C double bonds, carbonyl, CN, MeS and halogen groups are tolerable. This reaction can be used for the modification of complex molecules and carried out at a large scale.
- Xi, Xiaoxiang,Chen, Tieqiao,Zhang, Ji-Shu,Han, Li-Biao
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p. 1521 - 1524
(2018/02/19)
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- Application of Silicon-Initiated Water Splitting for the Reduction of Organic Substrates
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The use of water as a donor for hydrogen suitable for the reduction of several important classes of organic compounds is described. It is found that the reductive water splitting can be promoted by several metalloids among which silicon shows the best efficiency. The developed methodologies were applied for the reduction of nitro compounds, N-oxides, sulfoxides, alkenes, alkynes, hydrodehalogenation as well as for the gram-scale synthesis of several substrates of industrial importance.
- Gevorgyan, Ashot,Mkrtchyan, Satenik,Grigoryan, Tatevik,Iaroshenko, Viktor O.
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p. 375 - 382
(2018/06/04)
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- Mild Deoxygenation of Sulfoxides over Plasmonic Molybdenum Oxide Hybrid with Dramatic Activity Enhancement under Visible Light
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Harvesting solar light to boost commercially important organic synthesis still remains a challenge. Coupling of conventional noble metal catalysts with plasmonic oxide materials which exhibit intense plasmon absorption in the visible light region is a promising option for efficient solar energy utilization in catalysis. Herein, we for the first time demonstrate that plasmonic hydrogen molybdenum bronze coupled with Pt nanoparticles (Pt/HxMoO3-y) shows a high catalytic performance in the deoxygenation of sulfoxides with 1 atm of H2 at room temperature, with dramatic activity enhancement under visible light irradiation relative to dark conditions. The plasmonic molybdenum oxide hybrids with strong plasmon resonance peaks pinning at around 556 nm are obtained via a facile H-spillover process. Pt/HxMoO3-y hybrid provides excellent selectivity for the deoxygenation of various sulfoxides as well as pyridine N-oxides, in which drastically improved catalytic efficiencies are obtained under the irradiation of visible light. Comprehensive analyses reveal that oxygen vacancies massively introduced via a H-spillover process are the main active sites, and the reversible redox property of Mo atoms and strong plasmonic absorption play key roles in this reaction. The catalytic system works under extremely mild conditions and can boost the reaction by the assistance of visible light, offering an ultimately greener protocol to produce sulfides from sulfoxides. Our findings may open up a new strategy for designing plasmon-based catalytic systems that can harness visible light efficiently.
- Kuwahara, Yasutaka,Yoshimura, Yukihiro,Haematsu, Kohei,Yamashita, Hiromi
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p. 9203 - 9210
(2018/06/25)
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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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- An expeditious and efficient bromomethylation of thiols: Enabling bromomethyl sulfides as useful building blocks
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A facile and highly efficient method for the bromomethylation of thiols, using paraformaldehyde and HBr/AcOH, has been developed, which advantageously minimizes the generation of highly toxic byproducts. The preparation of 22 structurally diverse α-bromomethyl sulfides illustrates the chemo-tolerant applicability while bromo-lithium exchange and functionalization sequences, free radical reductions, and additions of the title compounds demonstrate their synthetic utility.
- Silva-Cuevas, Carolina,Paleo, Ehecatl,León-Rayo, David F.,Lujan-Montelongo, J. Armando
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p. 24654 - 24659
(2018/07/25)
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- Cesium carbonate-promoted synthesis of aryl methyl sulfides using: S -methylisothiourea sulfate under transition-metal-free conditions
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In the presence of cesium carbonate, an efficient synthesis of aryl methyl sulfides by the reactions of aryl halides with commercially available S-methylisothiourea sulfate is developed. This odourless and highly crystalline solid can be used as the subst
- Zhang, Caiyang,Zhou, You,Huang, Jintao,Tu, Canhui,Zhou, Xiaoai,Yin, Guodong
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p. 6316 - 6321
(2018/09/10)
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- Chemoenzymatic Deracemization of Chiral Sulfoxides
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The highly enantioselective enzyme methionine sulfoxide reductase A was combined with an oxaziridine-type oxidant in a biphasic setup for the deracemization of chiral sulfoxides. Remarkably, high ee values were observed with a wide range of substrates, thus providing a practical route for the synthesis of enantiomerically pure sulfoxides.
- Nosek, Vladimír,Mí?ek, Ji?í
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p. 9849 - 9852
(2018/07/31)
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- Electrochemical synthesis of methyl sulfoxides from thiophenols/thiols and dimethyl sulfoxide
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A new route for a one-pot synthesis of methyl sulfoxides from thiophenols/thiols and dimethyl sulfoxide using an electrochemical technique was developed. This protocol proceeded smoothly by employing electrons and hydrogen peroxide as clean oxidants, and a wide range of aromatic and aliphatic sulfoxides were synthesized in moderate to good yields.
- Du, Ke-Si,Huang, Jing-Mei
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p. 1405 - 1411
(2018/03/27)
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- Metal-free S-methylation of diaryl disulfides with di-tert-butyl peroxide
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An efficient approach for S-methylation of diaryl disulfides with di-tert-butyl peroxide under metal-free and neutral conditions was established. The present protocol shows good functional group tolerance to afford aryl methyl sulfides in moderate to good
- Wu, Xiangmei,Wang, Yan
-
supporting information
p. 1240 - 1243
(2018/03/08)
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- An Additive-Free, Base-Catalyzed Protodesilylation of Organosilanes
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We report an additive-free, base-catalyzed C-, N-, O-, and S-Si bond cleavage of various organosilanes in mild conditions. The novel catalyst system exhibits high efficiency and good functional group compatibility, providing the corresponding products in good to excellent yields with low catalyst loadings. Overall, this transition-metal-free process may offer a convenient and general alternative to current employing excess bases, strong acids, or metal-catalyzed systems for the protodesilylation of organosilanes.
- Yao, Wubing,Li, Rongrong,Jiang, Huajiang,Han, Deman
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p. 2250 - 2255
(2018/02/23)
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- Biocatalytic Preparation of Chiral Sulfoxides through Asymmetric Reductive Resolution by Methionine Sulfoxide Reductase A
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Here we report an environmentally friendly method for the preparation of chiral sulfoxides under high substrate concentration using recombinant methionine sulfoxide reductase A from Pseudomonas monteilii (pmMsrA) as a biocatalyst. Our results show that this enzyme can effectively accomplish the preparation of (R)-sulfoxides with approximately 50 % yield and 94–99 % enantiomeric excess through asymmetric reductive resolution of racemic sulfoxide. With the establishment of the enzyme regeneration system, the initial substrate concentration could be increased 40–100 times compared to our original report. The (R)-sulfoxides were obtained with high enantioselectivity under the substrate concentration up to 200 mm (approximately 32 g L?1), representing a quite high substrate concentration in biocatalytic preparation of chiral sulfoxides. Moreover, this system showed fairly good activity and enantioselectivity towards a series of ortho- and para-substituted phenyl methyl sulfoxides under high substrate concentration.
- Peng, Liaotian,Wen, Yuanmei,Chen, Yu,Yuan, Zhimei,Zhou, Yang,Cheng, Xiaoling,Chen, Yongzheng,Yang, Jiawei
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p. 3284 - 3290
(2018/06/04)
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- Rapid and efficient deoxygenation of sulfoxides to sulfides with tantalum(V) chloride/sodium iodide system
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TaCl5/NaI system converts a wide range of sulfoxides to the corresponding sulfides in high yields with short reaction times, under mild conditions. It is worth mentioning that this protocol is chemoselective and tolerates various functional groups (such as –Br, –Cl, –OCH3, –CHO, and –NO2) and double bond.
- Yoo, Byung Woo,Park, Jeeyeon,Shin, Hyo Jong,Yoon, Cheol Min
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p. 597 - 603
(2017/10/06)
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- B(C 6 F 5) 3 -Catalyzed Reduction of Sulfoxides and Sulfones to Sulfides with Hydrosilanes
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B(C 6 F 5) 3 is shown to catalyze the deoxygenation of sulfoxides and sulfones to the corresponding sulfides with Et 3 SiH as the stoichiometric hydride source. While the method is limited in terms of functional group tolerance, it is applicable to the reduction of alkyl/aryl-, aryl/aryl-, and alkyl/alkyl-substituted sulfoxides, including the benzyl/benzyl-substituted derivative. The same protocol converts alkyl/aryl- but not aryl/aryl-substituted sulfones into sulfides.
- Porwal, Digvijay,Oestreich, Martin
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p. 4698 - 4702
(2017/10/05)
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- B(C6F5)3-Catalyzed Deoxygenation of Sulfoxides and Amine N-Oxides with Hydrosilanes
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An efficient strategy for the deoxygenation of sulfoxides and amine N-oxides by using B(C6F5)3 and hydrosilanes was developed. This method provided the corresponding aromatic and aliphatic products in good to high yields and showed good functional-group tolerance under mild conditions.
- Ding, Fangwei,Jiang, Yanqiu,Gan, Shaoyan,Bao, Robert Li-Yuan,Lin, Kaifeng,Shi, Lei
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p. 3427 - 3430
(2017/07/04)
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- Kinetic resolution of phenyl methyl sulfoxides by mammalian methionine sulfoxide reductase A
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Chiral sulfoxides are widely used in organic synthesis as chiral auxiliaries. There are numerous strategies for the preparation of enantiomerically pure sulfoxides, based either on the enantioselective oxidation of sulphides or the enantiospecific reduction of sulfoxides. For both cases, bioconversion techniques have been developed and proposed for large-scale synthesis. Methionine sulfoxide reductase enzymes (MsrA and MsrB) catalyse the stereoselective conversion of methionine sulfoxide to methionine. MsrA can also catalyse the reduction of other exogenous sulfoxides, including p-tolyl methyl sulfoxide. However, the stereoselectivity towards this type of substrate is not yet well characterized. The activity and enantioselectivity of MsrA toward several aryl methyl sulfoxides is presented in this paper.
- Achilli, Cesare,Ciana, Annarita,Minetti, Giampaolo
-
supporting information
p. 4781 - 4782
(2017/11/29)
-
- Pummerer rearrangement using bis(p-nitrophenyl) phosphorazidate as an azidation reagent: A novel synthesis of azidomethyl sulfides
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A novel method for the synthesis of azidomethyl sulfides by Pummerer rearrangement using bis(p-nitrophenyl) phosphorazidate (p-NO2DPPA) as an azidation reagent was developed. Various methyl sulfoxides were converted into the corresponding azidomethyl sulfides. Importantly, this reaction enables the preparation of azidomethyl sulfides without the use of toxic or explosive azide sources.
- Ishihara, Kotaro,Shioiri, Takayuki,Matsugi, Masato
-
supporting information
p. 3932 - 3935
(2017/09/20)
-
- Copper nanoparticles supported on polyaniline-functionalized multiwall carbon nanotubes: An efficient and recyclable catalyst for synthesis of unsymmetric sulfides using potassium ethyl xanthogenate in water
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A new and powerful polyaniline-functionalized carbon nanotube-supported copper(II) nanoparticle catalyst was successfully prepared and evaluated as a heterogeneous catalyst for the one-pot synthesis of unsymmetric thioethers by coupling of aryl, alkyl and benzyl halides using potassium ethyl xanthogenate as source of sulfur in water. All of these reactions gave the desired products in good to excellent yields. The catalyst is available, air-stable and can be reused several times without significant loss in its catalytic activity.
- Hajipour, Abdol R.,Jajarmi, Saeideh,Khorsandi, Zahra
-
-
- Palladium-Catalyzed ipso-Borylation of Aryl Sulfides with Diborons
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A catalytic Miyaura-type ipso-borylation of aryl sulfides with diboron reagents has been achieved, providing arylboronate esters of synthetic use. The key conditions to transform inherently reluctant C-S bonds into C-B bonds include a palladium-NHC (N-heterocyclic carbene) precatalyst, bis(pinacolato)diboron, and lithium hexamethyldisilazide. This protocol is applicable to a reasonable range of aryl alkyl sulfides. Twofold borylation was observed in the reaction of diphenyl sulfide.
- Bhanuchandra,Baralle, Alexandre,Otsuka, Shinya,Nogi, Keisuke,Yorimitsu, Hideki,Osuka, Atsuhiro
-
supporting information
p. 2966 - 2969
(2016/07/06)
-
- En Route to a Practical Primary Alcohol Deoxygenation
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A long-standing scientific challenge in the field of alcohol deoxygenation has been direct catalytic sp3 C-O defunctionalization with high selectivity and efficiency, in the presence of other functionalities, such as free hydroxyl groups and amines widely present in biological molecules. Previously, the selectivity issue had been only addressed by classic multistep deoxygenation strategies with stoichiometric reagents. Herein, we propose a catalytic late-transition-metal-catalyzed redox design, on the basis of dehydrogenation/Wolff-Kishner (WK) reduction, to simultaneously tackle the challenges regarding step economy and selectivity. The early development of our hypothesis focuses on an iridium-catalyzed process efficient mainly with activated alcohols, which dictates harsh reaction conditions and thus limits its synthetic utility. Later, a significant advancement has been made on aliphatic primary alcohol deoxygenation by employing a ruthenium complex, with good functional group tolerance and exclusive selectivity under practical reaction conditions. Its synthetic utility is further illustrated by excellent efficiency as well as complete chemo- and regio-selectivity in both simple and complex molecular settings. Mechanistic discussion is also included with experimental supports. Overall, our current method successfully addresses the aforementioned challenges in the pertinent field, providing a practical redox-based approach to the direct sp3 C-O defunctionalization of aliphatic primary alcohols.
- Dai, Xi-Jie,Li, Chao-Jun
-
supporting information
p. 5433 - 5440
(2016/05/19)
-
- A mild, efficient, and selective procedure for the deoxygenation of sulfoxides with the TaCl5/indium system
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The TaCl5/In systemwas found to be a new reagent for reducing a wide range of structurally diverse sulfoxides to the corresponding sulfides with high yields under mild conditions. This protocol is chemoselective and tolerates several functional groups, such as Br, Cl, OCH3, CHO, and CH= CH2.
- Yoo, Byung Woo,Lee, Min Kyung,Yoon, Cheol Min
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p. 807 - 810
(2016/07/06)
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- Metal-Free, DTBP-Mediated Methylthiolation of Arylboronic Acids with Dimethyldisulfide
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An efficient method for the C-S bond formation via the coupling reaction of arylboronic acids with dimethyldisulfide has been developed under the metal-free conditions. This novel protocol provides an attractive route for the synthesis of aryl methyl sulf
- Wu, Xiang-Mei,Lou, Jia-Ming,Yan, Guo-Bing
-
supporting information
p. 2269 - 2273
(2016/10/30)
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- Deoxygenation of carbonyl compounds using an alcohol as an efficient reducing agent catalyzed by oxo-rhenium complexes
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This work describes the first methodology for the deoxygenation of carbonyl compounds using an alcohol as a green solvent/reducing agent catalyzed by oxo-rhenium complexes. The system 3-pentanol/ReOCl3(SMe2)(OPPh3) was successfully employed in the deoxygenation of several aryl ketones to the corresponding alkenes and also in the deoxygenation of aryl aldehydes to alkanes with moderate to excellent yields. The catalyst ReOCl3(SMe2)(OPPh3) can also be used in several catalytic cycles with good activity.
- Bernardo, Joana R.,Fernandes, Ana C.
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supporting information
p. 2675 - 2681
(2016/05/24)
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- Efficient reduction of sulfoxides with NaHSO3 catalyzed by I2
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An efficient method for the deoxygenation of sulfoxides into their corresponding sulfides at room temperature using NaHSO3 in the presence of catalytic I2 has been reported.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Moradi, Zahra
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p. 6610 - 6613
(2015/11/09)
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- A facile and efficient procedure for the deoxygenation of sulfoxides to sulfides with the HfCl4/Zn system
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Treatment of sulfoxides with the HfCl4/Zn system in acetonitrile at room temperature has been shown to provide the corresponding sulfides in high yields. This new methodology is highly chemoselective, tolerating several functional groups such as-Br,-Cl,-OCH3,-CHO and double bond.
- Yoo, Byung Woo,Yu, Bo Ran,Yoon, Cheol Min
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p. 358 - 363
(2015/06/22)
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- Electrophilic alkylation of pseudotetrahedral nickel(II) arylthiolate complexes
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A kinetic study is reported for reactions of pseudotetrahedral nickel(II) arylthiolate complexes [(TpR,Me)Ni-SAr] (TpR,Me = hydrotris{3-R-5-methyl-1-pyrazolyl}borate, R = Me, Ph, and Ar = C6H5, C6H4-4-Cl, C6H4-4-Me, C6H4-4-OMe, 2,4,6-Me3C6H2, 2,4,6-iPr3C6H2) with organic electrophiles R'X (i.e., MeI, EtI, BzBr) in low-polarity organic solvents (toluene, THF, chloroform, dichloromethane, or 1,2-dichloroethane), yielding a pseudotetrahedral halide complex [(TpR,Me)Ni-X] (X = Cl, Br, I) and the corresponding organosulfide R'SAr. Competitive reactions with halogenated solvents and adventitious air were also examined. Akin to reactions of analogous and biomimetic zinc complexes, a pertinent mechanistic question is the nature of the reactive nucleophile, either an intact thiolate complex or a free arylthiolate resulting from a dissociative pre-equilibrium. The observed kinetics conformed to a second-order rate law, first order with respect to the complex and electrophile, and no intermediate complexes were observed. In the absence of a mechanistically diagnostic rate law, a variety of mechanistic probes were examined, including kinetic effects of varying the metal, solvent, electrophile, and temperature, as well as the 3-pyrazolyl and arylthiolate substituents. Compared to zinc analogues, the effect of Ni-SAr covalency is also of interest herein. The results are broadly interpreted with respect to the disparate mechanistic pathways.
- Deb, Tapash,Jensen, Michael P.
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supporting information
p. 87 - 96
(2015/03/03)
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- N-Imidazolylation of Sulfoximines from N-Cyano Sulfoximines, 1-Alkynes, and N-Sulfonyl Azides
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The rhodium-catalyzed N-imidazolylation of N-sulfonyl-1,2,3-triazoles with a variety of N-cyano sulfoximines has been developed for the synthesis of N-imidazolyl sulfoximines via elimination of molecular nitrogen. Copper-catalyzed [3+2] cycloaddition followed by rhodium-catalyzed N-imidazolylation from 1-alkynes, N-sulfonyl azides, and N-cyano sulfoximines is also demonstrated for the synthesis of N-imidazolyl sulfoximines in a one-pot procedure.
- Kim, Sanghyuck,Kim, Ji Eun,Lee, Jinsub,Lee, Phil Ho
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supporting information
p. 3707 - 3717
(2016/01/25)
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- Chain Extension of Boronic Esters with Lithiooxiranes Generated by Sulfoxide-Metal Exchange - Stereocontrolled Access to 2°/2°, 2°/3°, and 3°/3° Vicinal Diols and Related Compounds
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Lithiooxiranes [LiCR1(O)CR2R3, R1 = H, Me; R2/R3 = H/Ph, H/tBu, Me/Ph], generated by sulfoxide-lithium exchange from stereodefined sulfinyl epoxides (with use of PhLi or tBuLi, THF, at or below -90 °C), were employed for the stereospecific reagent-controlled homologation of boronic esters R0-Bpin (R0 = BnCH2, allyl, cHex, Ph). Addition of TBSOTf to the intermediate ate complexes gave β-silyloxyboronates that were converted to vicinal diol monosilyl ethers by oxidative work-up with aq. NaOOH. The 2°/2° (4-32 %, dr > 98:2), 2°/3° (21-66 %, dr ≥ 65:35), and 3°/3° (59-68 %, dr ≥ 95:5) contiguous stereodiad-containing compounds created in this manner were typically obtained in a highly stereocontrolled manner. In general, cis-sulfinyl epoxides afforded anti-like stereodiads, whereas trans-sulfinyl epoxides afforded syn-like stereodiads; however, as a result of its suspected configurational instability, LiCMe(O)CHPh gave anti-like 2°/3° motifs regardless of sulfinyl epoxide stereochemistry.
- Alwedi, Embarek,Zakharov, Lev N.,Blakemore, Paul R.
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supporting information
p. 6643 - 6648
(2016/02/19)
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- 2-(Aryl-sulfonyl)oxetanes as designer 3-dimensional fragments for fragment screening: Synthesis and strategies for functionalisation
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2-Sulfonyl-oxetanes have been prepared, affording non-planar structures with desirable physicochemical properties for fragment based drug discovery. The oxetane motif was formed by an intramolecular C-C bond formation. The fragments were further functionalised via organometallic intermediates at the intact oxetane and aromatic rings. the Partner Organisations 2014.
- Morgan, Kate F.,Hollingsworth, Ian A.,Bull, James A.
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supporting information
p. 5203 - 5205
(2014/05/06)
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- NaBH3CN: A janus substitute for tin-free radical-based reactions
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Beside showing that thermal radical reactions (reduction, Giese reaction) are efficient if bromo-/iodosugars are treated with NaBH3CN and 2,2″-azobisisobutyronitrile, we explored new initiation conditions on the basis of CuI salts (≤0.5 equiv.) supposed to produce radicals from organobromides through a set. This was confirmed, as at about 50 C under an inert atmosphere acetobromoglucose was reduced to the rearranged 2-deoxyglucose and as N-allyl α-bromoamides reacted, depending on the conditions, either by reductive cyclization or atom-transfer radical cyclization. A related cyclization occurred upon using Cu(OAc)2. This and other assays showed the reduction by NaBH3CN of CuII salts, either added or formed in situ. Having both ionic and radical reactivity, NaBH 3CN appears as a Janus reagent that may be useful for tin-free radical chemistry under mild and very simple conditions. Copyright
- Guiard, Julie,Rahali, Yaniss,Praly, Jean-Pierre
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supporting information
p. 4461 - 4466
(2014/08/05)
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- A novel method for the reduction of sulfoxides with the N, N, N g, N g-tetrabromobenzene-1,3-disulfonamide (TBBDA)/PPh3 system
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A new method is described for the reduction of sulfoxides to sulfides using N,N,N',N'-tetrabromobenzene-1,3-disulfonamide [TBBDA] in combination with triphenylphosphine. Good to excellent yields, short reaction times, high efficiency and facile isolation of the desired products are the advantages of this method.
- Ghorbani-Vaghei, Ramin,Shiri, Lotfi,Ghorbani-Choghamarani, Arash
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p. 1002 - 1006
(2014/12/10)
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- Sulfoxide-to-sulfilimine conversions: Use of modified Burgess-type reagents
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Sulfoxides can directly be converted into N-cyanosulfilimines using a new Burgess-type reagent. By applying this strategy with a related reagent variant, synthetically valuable NH-sulfoximines have been prepared from sulfoxides via N-protected sulfilimines. The practical three-step reaction sequence is generally high yielding and applicable to a wide range of substrates. The sulfoxide-to-sulfilimine conversion can also be performed under solvent-reduced conditions in a ball mill. Copyright
- Hendriks, Christine M. M.,Lamers, Philip,Engel, Julien,Bolm, Carsten
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supporting information
p. 3363 - 3368
(2013/12/04)
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- Organocatalytic visible light mediated synthesis of aryl sulfides
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Photo-sensitized synthesis of arylsulfides from arenediazonium salts in the presence of eosin Y has been developed. This protocol exhibits high functional group tolerance and a wide substrate scope and is an attractive alternative to the thermal reaction that involves explosive intermediates.
- Majek, Michal,Von Wangelin, Axel Jacobi
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supporting information
p. 5507 - 5509
(2013/06/27)
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