Benzyl Phenyl Sulfide Research Articles

Mn-salen catalyzed enantioselective sulfimidation

Enantioselective sulfimidation of alkyl phenyl sulfides was achieved by using ( R, R)-Mn-salen complex 5 as a catalyst. In the sulfimidation of methyl and benzyl phenyl sulfides, high enantioselectivity (up to 89% ee) was attained in the presence of N-methylmorpholine N-oxide (NMO).

Photoinduced hydrogen- and electron-transfer processes between chloranil and aryl alkyl sulfides in organic solvents. Steady-state and time-resolved studies

The photochemical behavior of three aryl alkyl sulfides, thioanisole (TA), benzyl phenyl sulfide (BPS) and 4-methoxybenzyl phenyl sulfide (MBPS), sensitized by triplet chloranil (CA), was investigated by nanosecond laser flash photolysis and steady-state irradiation in CH2Cl2 and MeCN. The nature of the transients detected upon 355-nm laser excitation was independent of the molecular structure of the aryl alkyl sulfides but strongly affected by the solvent polarity. In particular, in CH2Cl2 the quenching process of triplet CA by aryl alkyl sulfides was accompanied by H-transfer, with formation of the CAH• and TA(-H)•/BPS(-H)•/MBPS(-H)• radicals. In contrast, a charge transfer process between triplet CA and aryl alkyl sulfides, with formation of the radical anion CA•− and radical cations of aryl alkyl sulfides, occurred in MeCN. In this solvent, a transient detected at long delay time was tentatively assigned to the anion CAH− formed by H-transfer between radical ions. In all experiments, transient species were characterized in terms of second-order decay rate constants and quantum yields of formation. Steady-state irradiation of the CA/TA system led to the stable photoadduct C6H5SCH2OC6Cl4OH in both CH2Cl2 and MeCN with quantum yields of 0.033 and 0.27, respectively. In contrast, aldehydes, thioacetals, and disulfides were the main products obtained upon irradiation of the CA/BPS and CA/MBPS systems. The photoaddition products were not observed, probably owing to their low stability. The nature of the photoproducts formed by irradiation of CA/aryl alkyl sulfides was independent of solvent properties, even though the reactivity was higher in MeCN than in CH2Cl2 .

Enantiopure p,p′-disubstituted 1,2-diphenylethane-1,2-diols as chiral inducers in the Ti-mediated oxidation of sulfides: a case of reversal of asymmetric induction by fluorine substitution

In the asymmetric oxidation of methyl p-tolyl sulfide, ( 2a), and benzyl phenyl sulfide ( 2b) by TBHP, mediated by a titanium complex with enantiopure (R,R)-p,p′-disubstituted-1,2-diphenylethane-1,2-diols, both the unsubstituted diol (R,R)- 1a and the p-OMe substituted diol (R,R)- 1b lead to sulfoxides of S configuration, with ee up to 99%. On the contrary the p-CF 3 substituted ligand (R,R)- 1c leads to significantly lower ee and in the case of 2a a reversal of asymmetric induction is observed.

Photochemical Electron-Transfer Reactions between Sulfides and Tetranitromethane. Oxidation vs Fragmentation of the Sulfide Radical-Cation Intermediate

Oxidation and/or fragmentation products are observed in the photochemical reaction of the alkyl phenyl sulfides 1a−d with tetranitromethane (TNM). The product distribution depends markedly on the substrate structure. Thus, methyl phenyl sulfide (1a) and benzyl phenyl sulfide (1b) give only the corresponding sulfoxides (oxidation). However, when the radical cation 1b•+ is generated by chemical oxidation with triarylaminium salts (Ar3N•+) in acetonitrile, in addition to oxidation fragmentation is also observed, and with an excess of Ar3N•+ oxidation is facilitated and no fragmentation is produced. For the photoreaction of diphenylmethyl phenyl sulfide (1c) with TNM, fragmentation is the main reaction, while for triphenylmethyl phenyl sulfide (1d) only this process is observed. The ease of C−S bond scission in these sulfur-centered radical cations 1•+ follows the ease of alkyl cation formation, i.e., Ph3C > Ph2CH > PhCH2 > CH3.

ChemInform Abstract: Oxidations of Benzyl and Phenethyl Phenyl Sulfides. Implications for the Mechanism of the Microsomal and Biomimetic Oxidation of Sulfides

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Oxidations of benzyl and phenethyl phenyl sulfides. Implications for the mechanism of the microsomal and biomimetic oxidation of sulfides

The study of the oxidation of 4-methoxyphenethyl phenyl sulfide and 3,4-dimethoxy-phenethyl phenyl sulfide with potassium 12-tungstocobalt(III)ate [Co(III)W] suggests that in the radical cations of 3,4,5-(MeO) 3PhCH 2SPh ( 4) and 2,4,6(MeO) 3PhCH 2SPh ( 5) the positive charge is not localized on the sulfur atom, but in the benzylic aromatic ring. Nevertheless, in the biomimetic and microsomal oxidation of 4 and 5 the products observed are exclusively sulfoxides and sulfones, which appears in contrast with a mechanism involving the formation of an intermediate sulfide radical cation followed by a fast oxygen rebound. A direct oxygen transfer mechanism seems most likely.

Oxidation of Aromatic Sulfides Photosensitized by TiO2 in CH3CN in the Presence of Ag2SO4. The Role of TiO2 in the Chemistry of Sulfide Radical Cations

A product study of the photooxidation of the aromatic sulfides 1−5 sensitized by TiO2 in MeCN, in the presence of Ag2SO4, has been carried out. With benzyl phenyl sulfide (1), 4-methoxybenzyl phenyl sulfide (2), and phenethyl phenyl sulfide (4), the photooxidation led mainly to aldehydic products, benzaldehyde, 4-methoxybenzaldehyde, and phenylacetaldehyde, respectively. With benzyl 4-methoxyphenyl sulfide (3), the major product was the corresponding sulfoxide. Diphenyl sulfoxide was the only product observed in the oxidation of diphenyl sulfide (5). These results suggest α-C−H deprotonation as the major reaction path for the radical cations of 1, 2, and 4, and an active role in this respect of the oxygenated basic sites present on the TiO2 surface is envisaged. An interaction of these oxygenated centers with the sulfur atom of the adsorbed radical cation is also suggested to explain the remarkable finding that substantial amounts of sulfoxide are observed with 3 and 5, in spite of the fact that the photooxidations were carried under nitrogen. Different than with the sulfides, the photooxidation of 4-methoxybenzyl phenyl sulfoxide leads exclusively to products of C−S bond cleavage, which is attributed to the much greater stability of sulfinyl than thiyl radicals.

Generation and Reactivity of Aromatic Thioether Radical Cations in Aqueous Solution As Studied by Pulse Radiolysis

The radical cations of thioanisole (1), p-methylthioanisole (2), and the benzyl phenyl sulfides 3−5 have been produced by pulse radiolysis in aqueous solutions, using SO4•- or Tl2+ as oxidizing species. The radical cations 1•+−5•+ exhibit very similar UV spectra, with strong absorptions between 300−350 and 500−600 nm. In contrast to aliphatic thioether radical cations, 1•+−5•+ do not undergo dimerization (via formation of a three-electron bond with the parent thioethers). In the absence of bases, 1•+ is a long-lived species with a lifetime >30 ms, whereas 3•+, 4•+, and 5•+ decay rapidly by both C−S bond and C−H bond cleavage with kC-H = 1.3 × 103 s-1 and kC-S = 1.3 × 103 s-1 for 3•+and kC-H = 0.95 × 103 s-1 and kC-S = 2.65 × 103 s-1 for 4•+. In the presence of OH- or HPO42-, also 1•+ undergoes a deprotonation process, with a rate larger than those of the benzyl phenyl sulfide radical cations. For example, the rate constant for the OH--induced deprotonation is 3.4 × 107 M-1 s-1 for 1•+and 9.5 × 106 M-1 s-1 for 3•+. Thioanisole radical cation 1•+ was also produced by reduction of thioanisole sulfoxide. Under these conditions, it was possible to study the reaction of 1•+ with a number of nucleophiles or electron donors. It was found that 1•+ reacts with I-, N3-, PhS-, PhSH, Br-, and SCN- by an electron transfer mechanism, producing the oxidized form of the nucleophile. This reaction is diffusion controlled with the first four nucleophiles, which are more easily oxidized than 1 (E° < 1.45 V); slower reactions were observed with SCN- (E° = 1.62 V) and with Br- (E° = 1.96 V). NO3- (E° = 2.3V) is unreactive (k < 106 M-1 s-1).

Photoinduced electron transfer reactions of benzyl phenyl sulfides promoted by 9,10-dicyanoanthracene

The photoinduced oxidation of benzyl phenyl sulfides 1–3 has been investigated in MeCN using 9,10-dicyanoanthracene as sensitizer in the presence of O 2 . In this reaction a sulfide radical cation is formed, which undergoes one or more of the three main reaction pathways opened to these species: C S bond cleavage, C H bond cleavage and S-oxidation. The former route (leading to benzylic products) was observed with all the substrates investigated, whereas the second (leading to benzaldehydes) operates only with 1 and 2 . Formation of sulfoxides was found solely in the photooxidation of 1 . The influence of substrate structures on the relative contribution of the three pathways as well as the role of O 2 in this respect are discussed. The competition between paths a-c has been studied in the 9,10-dicyanoanthracene (DCA) sensitized oxidation of 1–3 .

Sulfur- and nitrogen-containing phenol-formaldehyde co-resites for probing the thermal behaviour of heteroatomic forms in solid fuels

In order to probe the formation of sulfur- and nitrogen-containing gases during the pyrolysis and combustion of coals and other solid fuels, non-softening model substrates are required. In this respect, phenol-formaldehyde (PF) resins are ideal since they readily facilitate the incorporation of individual heteroatomic functions into a highly crosslinked matrix. A series of sulfur- and nitrogen-containing co-resites have been prepared using phenol with, as the second component, thiophene, dibenzothiophene, diphenylsulfide, benzyl phenyl sulfide, thioanisole, 8-hydroxyquinoline and 2-hydroxycarbazole. A mole ratio of 3 : 1 (phenol : heteroatom-containing component) was adopted in order to ensure that a reasonably high degree of crosslinking was achieved. Resoles containing diphenyldisulfide were also prepared but, due to the comparable bond strengths of the S S and C O linkages, a curing temperature of only 130°C was used to avoid cleavage of the disulfide bond. The virtually complete elimination of ether and metylol functions from the resoles by curing at 200°C was monitored by solid-state 13C nuclear magnetic resonance (n.m.r.) spectroscopy. The resultant resites were also characterized by sulfur K-edge X-ray absorption near-edge structure (XANES.) spectroscopy, X-ray photoelectron spectroscopy (X.p.s.) and differential scanning calorimetry (d.s.c.). Simple air oxidation was found to selectively convert the aliphatic-bound sulfur to a mixture of sulfones and sulfoxides. Applications of the resites in fuel science are described.

Substituent Effects on the Photocleavage of Benzyl-Sulfur Bonds. Observation of the "Meta Effect"

Benzyl phenyl sulfide has been used to investigate the photocleavage mechanism for benzyl-sulfur bonds. Four experiments have shown that the reaction goes through a radical intermediate. First, the photoproducts observed can all be justified by radical mechanisms. Second, the radical intermediate was trapped with a five hexenyl tether. Third, UV analysis of analogs for the 4-NO(2) derivative indicate no exciplex or electron transfer pathway. Fourth, no strong correlation is observed between sigma values and the quatum yields for loss of substituted benzyl phenyl sulide. The effect of oxygen on quantum yields is best observed after samples are thoroughly outgassed with consecutive freeze-pump-thaw cycles. It is shown that oxygen diminishes the substituent effect. Upon photolysis of the outgassed samples, the meta-substituted derivatives showed more significant variances than the para derivatives. The meta derivatives are most efficiently cleaved in the following order: 3-CN > 3-NO(2) > 3-CF(3) > 3-CH(3) > 3-OCH(3). These findings are justified by an increase in electron density of the radical ipso to the forming benzyl radical for the 3-OCH(3) derivative and a decrease in the electron density of the radical ipso to the forming benzyl radical for the 3-CN derivative.

Electrochemical behaviour of selenoorganic compounds—part 4. benzyl phenyl selenide

The electrochemical behaviour of benzyl phenyl selenide was investigated by voltammetry using a rotating platinum disk electrode, cyclic voltammetry, controlled potential coulometry and electrolysis. The measurements were made in acetonitrile solution. In contrast to the case of benzyl phenyl sulfide, the oxidation products diphenyl diselenide, benzaldehyde and N-benzylacetamide result from the evolution of benzyl phenyl selenoxide and not from the corresponding initially formed radical cation

Preparation of a thiophenol/formaldehyde resin; its structure and the mechanism of its pyrolysis

A thiophenol/formaldehyde resin (TPFR) was synthesized under basic (NaOH) conditions, and its structure was thermally investigated by isothermal pyrolysis, under fluidizedbed conditions, at various temperatures. The pyro-products, volatilized during pyrolysis, were trapped and most of them were identified by GC and GC/MS to be sulfur-containing compounds, i.e. thiophenol, methylthiobenzene, benzothiophenes, diphenyl sulfide, diphenyl disulfide, thioxanthene, thianthrene and p-mercaptobenzyl phenyl sulfide (MBPS). The relative distribution of the condensed pyro-products was temperature dependent. The kinetic profiles of the pyrolysis were evaluated in relation to the spatial structure. The thermal behavior of a structurally similar monomer, benzyl phenyl sulfide (BPS), was studied under the same pyrolytic conditions. The similarities and the differences between the thermal behaviors of BPS and TPFR are discussed and decomposition mechanisms are proposed. The main conclusions of this work are: (i) TPFR is a highly branched polymer built from BPS units; (ii) cleavage of the benzylic CS bond, which is the weakest bond in the resin, is the key step in the formation of most of the pyro-products; (iii) the structure of TPFR indicates that the polymerizations mechanism of thiophenol and formaldehyde differs considerably from that of phenol/formaldehyde resins. The proposed mechanisms for polymerization and for thermal decomposition are discussed in relation to our previous studies on phenol/formaldehyde resins.

ChemInform Abstract: Thioalkylation of Reactive Aromatic Compounds with α‐( Benzotriazol‐1‐yl)benzyl Phenyl Sulfide.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Thioalkylation of Reactive Aromatic Compounds with α-(Benzotriazol-1-yl)benzyl Phenyl Sulfide

1-[α-(Phenylthio)benzyl]- and 1-[(4-methylphenyl)(phenylthio)methyl]benzotriazole, readily available from benzotriazole, an aldehyde and thiophenol, react with a variety of active aromatic compounds under mild conditions to give the thioalkylation products in moderate to good yields

Preparation and properties of ethylpalladium thiolate complexes. Reaction with organic halides leading to C–S bond formation; crystal structure of trans-[PdEt(Br)(PMe3)2

The complexes trans-[PdEt(SR)(PMe3)2](R = Ph, 1; or C6H4Me-p, 2) and trans-[PdMe(SPh)(PMe3)2]3 have been prepared by reactions of trans-[PdEt2(PMe3)2] or trans-[PdMe2(PMe3)2] with allyl aryl sulphides. Complex 1 reacts with various organic halides such as allyl chloride, benzyl bromide and methyl iodide to give allyl phenyl sulphide, benzyl phenyl sulphide and methyl phenyl sulphide, respectively; trans-[PdEt(X)(PMe3)2](X = Cl, 4; Br, 5; or I, 6) were isolated from the reaction mixtures. The complex trans-[PdEt(OPh)(PMe3)2(HOPh)] also reacts with allyl chloride to give allyl phenyl ether together with complex 4. The structure of complex 5 has been determined by X-ray crystallography: orthorhombic, space group Pbca with a= 12.306(3), b= 20.078(5), c= 11.753(2)A, Z= 8, R= 0.036 and R′= 0.042. It has a square-planar co-ordination around the palladium centre. The reaction of allyl chloride with complex 1 in toluene obeys first-order kinetics in the concentrations of both allyl chloride and 1.

ChemInform Abstract: Adsorption and Decomposition of Benzyl Phenyl Sulfide on Silver Surface Investigated by Raman Spectroscopy.

ChemInformVolume 21, Issue 27 Physical Organic Chemistry ChemInform Abstract: Adsorption and Decomposition of Benzyl Phenyl Sulfide on Silver Surface Investigated by Raman Spectroscopy. Y. H. YIM, Dep. Chem., Seoul Natl. Univ., Seoul 151-742, KoreaSearch for more papers by this authorK. KIM, Dep. Chem., Seoul Natl. Univ., Seoul 151-742, KoreaSearch for more papers by this authorM. S. KIM, Dep. Chem., Seoul Natl. Univ., Seoul 151-742, KoreaSearch for more papers by this author Y. H. YIM, Dep. Chem., Seoul Natl. Univ., Seoul 151-742, KoreaSearch for more papers by this authorK. KIM, Dep. Chem., Seoul Natl. Univ., Seoul 151-742, KoreaSearch for more papers by this authorM. S. KIM, Dep. Chem., Seoul Natl. Univ., Seoul 151-742, KoreaSearch for more papers by this author First published: July 3, 1990 https://doi.org/10.1002/chin.199027037AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume21, Issue27July 3, 1990 RelatedInformation

Adsorption and decomposition of benzyl phenyl sulfide on silver surface investigated by Raman spectroscopy

The surface-enhanced Raman scattering (SERS) of benzyl phenyl sulfide adsorbed on silver surface has been investigated. Benzyl phenyl sulfide was found to adsorb on the surface via its sulfur atom. Photodecomposition of adsorbed benzyle phenyl sulfide produced the phenylthio moiety on the surface. Two different SER spectra were obtained depending on the presence of Cl{sup {minus}} or BH{sub 4}{sup {minus}} ions. These are interpreted as due to the orientational differences caused by the different surface potential and coadsorbed ions.

REACTIONS OF BENZYL PHENYL SULFIDE NEAT AND IN DENSE POLAR SOLVENTS

ABSTRACT The reactions of benzylphenylsulfide (BPS) neat, in tetralin, in dense water, and in supercritical methanol were studied. A free-radical mechanism described the neat pyrolysis of BPS to the major products toluene, thiophenol, diphenyldisulfide, and diphenylsulfide. An analytical rate expression deduced from this mechanism was consistent with results from both neat pyrolysis and copyrolysis with added thiophenol. Reaction in dense water yielded benzaldehyde, whereas reaction in super critical methanol yielded methylphenylsulfide and benzaldehyde, as additional primary products. Thus reaction in water and methanol was by parallel pyrolysis and solvolysis pathways.

The inhibitory effect of p-trifluoromethyl substitution on the hepatic microsomal metabolism of benzyl phenyl sulphide

The inhibitory effect of p-trifluoromethyl substitution on the hepatic microsomal metabolism of benzyl phenyl sulphide