100-68-5Relevant articles and documents
Pd-catalyzed synthesis of biphenyls with methylthio group
Zhang, Zhiqiang,Hu, Zhizhi,Yu, Zhixiao,Chi, Haijun,Lei, Peng,Wang, Yue,He, Ren
, p. 683 - 690 (2007)
The synthesis of unsymmetrical biaryls with a methylthio group is achieved using the air-stable palladium-phosphinous acid complexes, [(t-Bu)2P(OH)]2 PdCl2 (POPd), as the catalyst. A great variety of substituted bromobenzenes having electron-withdrawing and electron-donating functional groups in para and meta positions have been successfully coupled with 3-methylthiophenylboronic acid. Copyright Taylor & Francis Group, LLC.
Photocatalytic deoxygenation of sulfoxides to sulfides over titanium(IV) oxide at room temperature without use of metal co-catalysts
Kominami, Hiroshi,Nakanishi, Kousuke,Yamamoto, Satoshi,Imamura, Kazuya,Hashimoto, Keiji
, p. 100 - 103 (2014)
Deoxygenation of sulfoxides was examined in acetonitrile suspensions of metal-free titanium(IV) oxide (TiO2) under irradiation of UV light at room temperature. Experimental results indicate that deoxygenation was induced by the TiO2
Impregnated palladium on magnetite as catalyst for multicomponent reductive amination reactions and other related reducing processes
Cano, Rafael,Yus, Miguel,Ramón, Diego J.
, p. 8079 - 8085 (2011)
The impregnated palladium on magnetite catalyst is a versatile system for different reduction processes using inexpensive polymehtylhydrosiloxane, including multicomponent reductive amination reactions, and aldehyde, imine, sulfinimide and sulfoxide reductions. This catalyst avoids the use of any type of expensive and quite expensive organic ligand, showing excellent yields, under mild reaction conditions. The catalyst is easily removed from the reaction medium, just by using a magnet. The catalytic system is very selective permitting the discrimination between ketones and aldehydes in the reductive amination process.
Efficient reduction of sulfoxides with NaHSO3 catalyzed by I2
Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Moradi, Zahra
, p. 6610 - 6613 (2015)
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.
Giannotti,Merle
, p. 45,53 (1976)
Drabowicz,Mikoxasczyk
, p. 138 (1978)
Unprecedented synthesis of iron-NHC complexes by C-H activation of imidazolium salts. Mild catalysts for reduction of sulfoxides
Cardoso, Joao M.S.,Royo, Beatriz
, p. 4944 - 4946 (2012)
A direct synthesis of bidentate cyclopentadienyl-functionalised NHC-iron(ii) complexes by using imidazolium salts and commercially available Fe3(CO)12 is developed. These well-defined iron-NHC complexes efficiently catalyse the reduction of sulfoxides under mild conditions. Radical scavenging experiments indicate the presence of free radicals in the catalytic reaction. The Royal Society of Chemistry 2012.
SNAr Nucleophilic Substitutions of Cr(CO)3-Complexed Aryl Halides with Thiolates under Phase-Transfer Conditions
Alemagna, Andreina,Buttero, Paola Del,Gorini, Carlo,Landini, Dario,Licandro, Emanuela,Maiorana, Stefano
, p. 605 - 607 (1983)
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Dealkylation of Quaternary Ammonium Salts by Thiolate Anions: A Model of the Cobalamin-independent Methionine Synthase Reaction.
Hilhorst, Ellen,Chen, Tjoe B. R. A.,Iskander, Atef S.,Pandit, Upendra K.
, p. 7837 - 7848 (1994)
The reactions of thiolate ions derived from thiophenol and homocysteine with substituted quaternary ammonium salts result in alkyl transfer from nitrogen to sulfur.A radical mechanism for this transalkylation, accounts for the reactivity pattern of the substrate salts.In a model study of the cobalamin-independent methionine synthase reaction, 5,5,6,7-tetramethyl-5,6,7,8-tetrahydropteridinium salt (25), which can be considered as a model for the natural coenzyme 5-CH3H4-folate (1), was allowed to react with the thiolate of homocysteine, whereupon the formation of methionine was observed in good yield.These results suggest that in the enzymatic process the N(5)-CH3 bond may be activated for the methyl transfer step, by coordination of the N(5) with an electrophile or a proton at the active site.
Convenient synthesis of electron-donating substituted benzonitriles by photolysis of phenyl halides and esters
Dichiarante, Valentina,Fagnoni, Maurizio,Albini, Angelo
, p. 3001 - 3003 (2006)
Irradiation of electron-donating substituted phenyl halides (fluorides and chlorides) or esters (mesylates, triflates and phosphates) in aqueous MeCN in the presence of KCN gives the corresponding benzonitriles in 48 to 100% yield through an ArSN1 reaction with the intermediacy of a triplet phenyl cation. The Royal Society of Chemistry 2006.
Photoredox catalysis for oxygenation/deoxygenation between sulfides and sulfoxides by visible-light-responsive polyoxometalates
Suzuki, Kosuke,Jeong, Jinu,Yamaguchi, Kazuya,Mizuno, Noritaka
, p. 1014 - 1021 (2016)
In this paper, we report the unique visible-light-responsive photoredox catalysis of a divacant lacunary silicotungstate TBA4H4[γ-SiW10O36] (SiW10) for functional group transformations of sulfur-containing compounds; namely, (i) aerobic oxygenation of sulfides to sulfoxides and (ii) deoxygenation of sulfoxides to sulfides. In the presence of suitable additives, such as Ce3+ (electron transfer mediator for oxygenation) and an alcohol (electron and proton donor for deoxygenation), SiW10 shows visible-light-induced charge transfers by using the newly formed highest occupied molecular orbitals derived from the coordinating Ce3+ or alcohol at the vacant site of SiW10. Consequently, oxygenation of sulfides and deoxygenation of sulfoxides can selectively proceed by irradiation with visible light (λ > 400 nm) to afford the corresponding desired products in high yields. The SiW10 photocatalysts can readily be recovered and reused for these transformations. Based on evidence from several experiments, the roles of the additives as well as the reaction mechanisms for these transformations are also discussed.
Niedzielski et al.
, p. 1694,1696 (1964)
Thiophenol-Promoted Radical Chain Reduction of α-Substituted Isobutyrophenones by 1,3-Dimethyl-2-phenylbenzimidazoline
Tanner, Dennis D.,Chen, Jian Jeffrey
, p. 662 - 666 (1992)
The reduction of α-haloacetophenones and α-halopropiophenones by 1,3-dimethyl-2-phenylbenzimidazoline (DMBI) have been reported to proceed via an electron-transfer free-radical chain mechanism.The reduction of α-haloisobutyrophenones did not proceed by the chain sequence.We mow report that initiated reductions of α-bromo- and α-chloroisobutyrophenones (IIIa,b) have been found to be promoted by the addition of thiophenol.Isobutyrophenone was formed as the major product via a free-radical chain process.During the PhSH-promoted DMBI reduction of IIIa,b a minor product, α-(phenylthio)isobutyrophenone (IV), was also formed via nucleophilic substitution.The chain propagation steps involve the efficient hydrogen atom transfers between PhCOCMe2. and PhSH and between PhS. and DMBI.The facile hydrogen transfer between PhS. and DMBI was comfirmed by carrying out the radical-chain reduction of PhSSPh with DMBI.
Facile and mild reduction of sulfoxides to sulfides with TiCl4/Sm system
Wang,Zhang
, p. 3545 - 3547 (1995)
TiCl4/Sm system reduces sulfoxides rapidly to the corresponding sulfides in good yields in THF at room temperature.
Discovery and application of methionine sulfoxide reductase B for preparation of (S)-sulfoxides through kinetic resolution
Wen, Yuanmei,Peng, Liaotian,Zhou, Yang,Peng, Tao,Chen, Yu,Cheng, Xiaoling,Chen, Yongzheng,Yang, Jiawei
, (2020)
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.
Formation of σ- and π-type dimer radical cations by the photochemical one-electron oxidation of aromatic sulfides
Yokoi, Hajime,Hatta, Akio,Ishiguro, Katsuya,Sawaki, Yasuhiko
, p. 12728 - 12733 (1998)
The formation of dimer radical cations from aromatic sulfides has been studied by photochemical one-electron oxidation in acetonitrile. When dicyanonaphthalene and thioanisole in acetonitrile were irradiated with nanosecond laser flash (308 nm), two types of dimer radical cations were detected at 470 and 800 nm at the expense of the monomer radical cation (520 nm). The intramolecular formation of similar radical ion complexes was observed for the cases of 1,n-bis(phenylthio)alkanes with n = 3 and 4, while bissulfides with n = 2, 6, and 8 showed radical cation spectra quite different from the above cases of n = 3 and 4. These facts indicate that dimer radical cations absorbing at around 460-500 nm are assigned as the σ- type complex of the sulfur-sulfur three-electron bond and that radical cations absorbing at around 800 nm are of the π-type complex associated with two phenylthio groups. For the case of p-methylthioanisole the formation of π-type dimer was shown to be reduced owing to the steric hindrance of two methyl groups. No formation of dimer radical cations was observed for cases of p-methoxythioanisole and diphenyl sulfide where the corresponding monomer radical cations are stabilized by the delocalization of positive charge on the sulfur atom. The density functional BLYP/6-31G* calculations on thioanisole predicted the existence of σ- and π-type dimer radical cations, in accordance with the experimental observation of approximately equal stability.
α-Effect with Substituted N-Methylbenzohydroxamates and Substituted Phenyldimethylsulfonium Salts: Toward Understanding of an Intrinsic α-Effect
Fountain,Dunkin, Timothy W.,Patel, Kamlesh D.
, p. 2738 - 2741 (1997)
Increasing electron demand in the reactions of G-NMBH anions with substituted phenyldimethylsulfonium ions decreases the α-effect for the methyl transfers toward 1.0 (zero effect). An extrapolation shows the possibility of an inverse effect (3 group. These correlations indicate inclusion of some SET character into the wavefunction of the SN2 transition state for these reactions, in agreement with the Shaik and Pross SCD model of the SN2 reaction.
Reversible Intramolecular P-S Bond Formation Coupled with a Ni(0)/Ni(II) Redox Process
Oh, Seohee,Lee, Yunho
, p. 1586 - 1592 (2016)
P-S bond formation/cleavage mediated by a nickel ion supported by a PPP ligand (PPP = P[2-PiPr2-C6H4]2-) has been investigated herein. To gain an entry into this chemistry, a mononuclear thiolato nickel complex, (PPP)Ni(SAr) (1a,b) was prepared by treating the chloride starting material with NaSPh. Upon carbonylation, this complex produces a nickel(0) monocarbonyl species, (PPSArP)Ni(CO) (2a,b), in which the thiolate migrates onto the central P of the ligand to give a P-S bond and two-electron reduction of a nickel(II) center. The reaction undergoes via a pseudo-first-order decay with respect to consumption of a nickel(II) thiolato species, suggesting an intramolecular reaction under the excess CO(g) conditions. The reverse reaction involving P-S bond cleavage with concomitant decarbonylation occurs to regenerate 1a,b in benzene. Reaction of 2a with trityl chloride results in Ph3CSPh formation, whereas the reaction with MeI gives methylation at a phosphide moiety or a thiolate group.
Application of alkoxy-λ6-sulfanenitriles as strong alkylating reagents
Hao, Wei,Fujii, Takayoshi,Dong, Tiaoling,Wakai, Youko,Yoshimura, Toshiaki
, p. 193 - 198 (2004)
Alkoxy-λ6-sulfanenitriles were found to be versatile alkylating reagents toward various nucleophiles bearing at least one proton such as methanol, phenol, thiophenols, carboxylic acids, ptoluenesulfonic acid, hydrochloric acid, and primary and secondary amines. Reactivity of the alkoxy group of the λ6-sulfanenitriles showed an opposite trend to the usual SN2 character, i.e. Me (la), Pr (1b), and Bu (1d) ? i-Pr (1c). In the presence of p-TsOH, alkyl tosylates were predominantly formed instead of the alkylation products of nucleophiles. In addition, even a sterically hindered substrate, neopentyloxy-λ6-sulfanenitrile, was found to undergo an SN2 reaction toward thiophenol without any rearrangement product to give neopentyl phenyl sulfide in good yield.
Drabowicz,Mikolasczyk
, p. 527 (1976)
Hydrodediazoniation of dry arenediazonium o-benzenedisulfonimides with hydrogen peroxide
Barbero, Margherita,Degani, Iacopo,Dughera, Stefano,Fochi, Rita
, p. 2386 - 2390 (2004)
This report describes the hydrodediazoniation of dry arenediazonium o-benzenedisulfonimides 1 with hydrogen peroxide (2) in THF at reflux. The new procedure is general, giving positive results in the presence of both electron-donating and electron-withdrawing substituents. Furthermore, it does not suffer from steric effects and always gives the pure reduction products 3 in excellent yields (15 examples, average yield = 93%). All the reactions show over 90% recovery of o-benzenedisulfonimide (4) that can be reused to prepare the salts 1. The collateral proofs we performed led us to hypothesize, for this reaction, a free-radical chain mechanism in which 2 is the exclusive hydrogen source in the arenes Ar-H 3.
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Hedstrand et al.
, p. 1255 (1978)
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A simple and efficient method for reduction of sulfoxide under solvent-free conditions
Pourmousavi, Seied Ali,Salehi, Parvin
, p. 803 - 807 (2010)
Benzyl DABCO bromide was found to be an efficient and mild reagent for the reduction of sulfoxides to the corresponding sulfide using sulfuric acid adsorbed silica gel under solvent-free conditions at room temperature.
Mild and efficient deoxygenation of sulfoxides with titanium(IV) chloride/sodium iodide reagent system
Balicki
, p. 155 - 156 (1991)
Dialkyl, diaryl and alkyl aryl sulfoxides were readily deoxygenated to the corresponding sulfides in excellent yields with titanium(IV) chloride/sodium iodide reagent system at room temperature.
A mild, efficient, and selective procedure for the deoxygenation of sulfoxides with the TaCl5/indium system
Yoo, Byung Woo,Lee, Min Kyung,Yoon, Cheol Min
, p. 807 - 810 (2016)
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.
N-bromosuccinimide/HCl mediated reduction of sulfoxides to sulfides
Wang, Jianqiang,Shi, Fangmin,Dai, Dongyan,Xiong, Liping,Yang, Yongpo
supporting information, p. 439 - 443 (2021/02/03)
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.
Ceramic boron carbonitrides for unlocking organic halides with visible light
Yuan, Tao,Zheng, Meifang,Antonietti, Markus,Wang, Xinchen
, p. 6323 - 6332 (2021/05/19)
Photochemistry provides a sustainable pathway for organic transformations by inducing radical intermediates from substrates through electron transfer process. However, progress is limited by heterogeneous photocatalysts that are required to be efficient, stable, and inexpensive for long-term operation with easy recyclability and product separation. Here, we report that boron carbonitride (BCN) ceramics are such a system and can reduce organic halides, including (het)aryl and alkyl halides, with visible light irradiation. Cross-coupling of halides to afford new C-H, C-C, and C-S bonds can proceed at ambient reaction conditions. Hydrogen, (het)aryl, and sulfonyl groups were introduced into the arenes and heteroarenes at the designed positions by means of mesolytic C-X (carbon-halogen) bond cleavage in the absence of any metal-based catalysts or ligands. BCN can be used not only for half reactions, like reduction reactions with a sacrificial agent, but also redox reactions through oxidative and reductive interfacial electron transfer. The BCN photocatalyst shows tolerance to different substituents and conserved activity after five recycles. The apparent metal-free system opens new opportunities for a wide range of organic catalysts using light energy and sustainable materials, which are metal-free, inexpensive and stable. This journal is
Trialkylammonium salt degradation: Implications for methylation and cross-coupling
Assante, Michele,Baillie, Sharon E.,Juba, Vanessa,Leach, Andrew G.,McKinney, David,Reid, Marc,Washington, Jack B.,Yan, Chunhui
, p. 6949 - 6963 (2021/06/02)
Trialkylammonium (most notably N,N,N-trimethylanilinium) salts are known to display dual reactivity through both the aryl group and the N-methyl groups. These salts have thus been widely applied in cross-coupling, aryl etherification, fluorine radiolabelling, phase-transfer catalysis, supramolecular recognition, polymer design, and (more recently) methylation. However, their application as electrophilic methylating reagents remains somewhat underexplored, and an understanding of their arylation versus methylation reactivities is lacking. This study presents a mechanistic degradation analysis of N,N,N-trimethylanilinium salts and highlights the implications for synthetic applications of this important class of salts. Kinetic degradation studies, in both solid and solution phases, have delivered insights into the physical and chemical parameters affecting anilinium salt stability. 1H NMR kinetic analysis of salt degradation has evidenced thermal degradation to methyl iodide and the parent aniline, consistent with a closed-shell SN2-centred degradative pathway, and methyl iodide being the key reactive species in applied methylation procedures. Furthermore, the effect of halide and non-nucleophilic counterions on salt degradation has been investigated, along with deuterium isotope and solvent effects. New mechanistic insights have enabled the investigation of the use of trimethylanilinium salts in O-methylation and in improved cross-coupling strategies. Finally, detailed computational studies have helped highlight limitations in the current state-of-the-art of solvation modelling of reaction in which the bulk medium undergoes experimentally observable changes over the reaction timecourse. This journal is
