Benzyl Methyl Sulfide Research Articles

Solar Light Driven H2O2 Production and Selective Oxidations Using a Covalent Organic Framework Photocatalyst Prepared by a Multicomponent Reaction

AbstractA chemically stable 2D microporous COF (PMCR‐1) was synthesized via the multicomponent Povarov reaction. PMCR‐1 exhibits a remarkable and long‐term stable photocatalytic H2O2 production rate (60 h) from pure and sea water under visible light. The H2O2 production is markedly enhanced when benzyl alcohol (BA) is added as reductant, which is also due to a strong π–π interaction of BA with dangling phenyl moieties in the COF pores introduced by the multicomponent Povarov reaction. Motivated by the concomitant BA oxidation to benzaldehyde during H2O2 formation, the photocatalytic oxidation of various organic substrates such as benzyl amine and methyl sulfide derivatives was investigated. It is shown that the well‐defined micropores of PMCR‐1 enable size‐selective photocatalytic oxidation.

Solar Light Driven H2 O2 Production and Selective Oxidations Using a Covalent Organic Framework Photocatalyst Prepared by a Multicomponent Reaction.

A chemically stable 2D microporous COF (PMCR-1) was synthesized via the multicomponent Povarov reaction. PMCR-1 exhibits a remarkable and long-term stable photocatalytic H2 O2 production rate (60 h) from pure and sea water under visible light. The H2 O2 production is markedly enhanced when benzyl alcohol (BA) is added as reductant, which is also due to a strong π-π interaction of BA with dangling phenyl moieties in the COF pores introduced by the multicomponent Povarov reaction. Motivated by the concomitant BA oxidation to benzaldehyde during H2 O2 formation, the photocatalytic oxidation of various organic substrates such as benzyl amine and methyl sulfide derivatives was investigated. It is shown that the well-defined micropores of PMCR-1 enable size-selective photocatalytic oxidation.

Advanced investigation of a putative adsorption process of nine non key food odorants (non-KFOs) on the broadly tuned human olfactory receptor OR2W1: Statistical physics modeling and molecular docking study

In the present paper, statistical physics formalism was used to understand the olfactory perception via the investigation of dose-olfactory response curves of a putative adsorption process of nine non key food odorants (non-KFOs) on the broadly tuned human olfactory receptor OR2W1, in order to quantitative characterize the interactions between the nine studied non-KFOs, i. e., furfuryl sulfide, furfuryl disulfide, benzyl methyl disulfide, furfuryl methyl disulfide, benzyl methyl sulfide, 1-phenylethanethiol, benzyl mercaptan, furfuryl methyl sulfide and 3-phenylpropanol molecules and OR2W1 binding sites at a molecular level. Two advanced adsorption models have been proposed: the advanced monolayer monoenergy model (monolayer model with identical and independent olfactory receptor binding sites) (Model 1) and the advanced monolayer model with two independent types of olfactory receptor binding sites (Model 2). It was concluded that the monolayer monoenergy model was selected as the most adequate model to fit the experimental dose-olfactory response curves tabulated in literature. Actually, the numerical values of the three fitted physico-chemical parameters (RM1, n and C1) were obtained by a non-linear regression. Indeed, modeling results suggested that the number of docked non-KFOs per OR2W1 binding site n values (1.24 < n < 1.94) was always superior to 1, which indicated the non-parallel orientation of the studied odorants on the olfactory receptor and the multi-molecular adsorption mechanism. The estimated molar adsorption energy ΔEa values (ranged from 6.07 to 12.16 kJ/mol) for the nine olfactory systems confirmed the physical the exothermic characters of the adsorption process since ΔEa values were lower than 40 kJ/mol and positive. Furthermore, these estimated parameters were applied to characterize stereographically and energetically the interaction between the nine non-KFOs and OR2W1 through the determination of the human receptor binding site size distributions (RSDs) and the adsorption energy distributions (AEDs), which were spread out from 0.25 to 6.50 nm and from 0 to 22.50 kJ/mol, respectively. The docking computation between these nine non-KFOs and OR2W1 proved that the estimated binding affinities were belonged to the adsorption energies spectrum in general and the specific adsorption energy band or the molecular vibration modes limited spectrum (between 2.50 kJ/mol and 17 kJ/mol) (approximate olfactory band).

Volatile scent chemicals in the urine of the red fox, Vulpes vulpes

The red fox is a highly adaptable mammal that has established itself world-wide in many different environments. Contributing to its success is a social structure based on chemical signalling between individuals. Urine scent marking behaviour has long been known in foxes, but there has not been a recent study of the chemical composition of fox urine. We have used solid-phase microextraction and gas chromatography-mass spectrometry to analyze the urinary volatiles in 15 free-ranging wild foxes (2 female) living in farmlands and bush in Victoria, Australia. Foxes here are routinely culled as feral pests, and the urine was collected by bladder puncture soon after death. Compounds were identified from their mass spectra and Kovats retention indices. There were 53 possible endogenous scent compounds, 10 plant-derived compounds and 5 anthropogenic xenobiotics. Among the plant chemicals were several aromatic apocarotenoids previously found in greater abundance in the fox tail gland. They reflect the dietary consumption of carotenoids, essential for optimal health. One third of all the endogenous volatiles were sulfur compounds, a highly odiferous group which included thiols, methylsulfides and polysulfides. Five of the sulfur compounds (3-isopentenyl thiol, 1- and 2-phenylethyl methyl sulfide, octanethiol and benzyl methyl sulfide) have only been found in foxes, and four others (isopentyl methyl sulfide, 3-isopentenyl methyl sulfide, and 1- and 2-phenylethane thiol) only in some canid, mink and skunk species. This indicates that they are not normal mammalian metabolites and have evolved to serve a specific role. This role is for defence in musteloids and most likely for chemical communication in canids. The total production of sulfur compounds varied greatly between foxes (median 1.2, range 0.4-32.3 μg 'acetophenone equivalents'/mg creatinine) as did the relative abundance of different chemical types. The urinary scent chemistry may represent a highly evolved system of semiochemicals for communication between foxes.

Safety and efficacy of eight compounds belonging to different chemical groups when used as flavourings for cats and dogs.

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of 23 compounds belonging to different chemical groups. This opinion concerns eight out of the 23 compounds, which are currently authorised for use as flavours in food. The Panel concludes that the eight additives are safe for cats and dogs at the proposed use level: phenylmethanethiol [12.005] and benzyl methyl sulfide [12.077] at 0.05 mg/kg complete feed; 2‐pentylthiophene [15.096] at 0.1 mg/kg complete feed; tridec‐2‐enal [05.078] and 12‐methyltridecanal [05.169] at 0.5 mg/kg complete feed; 2,5‐dimethylphenol [04.019] at the 1 mg/kg complete feed; hexa‐2(trans),4(trans)‐dienal [05.057] at 1.5 mg/kg complete feed; 2‐ethyl‐4‐hydroxy‐5‐methyl‐3(2H)‐furanone [13.084] at 2.25 mg/kg complete feed. In the absence of studies to assess the safety for the user, the FEEDAP Panel cannot conclude on the safety for the users when handling the additives. Since all eight compounds are used in food as flavourings, and their function in feed is essentially the same as that in food no further demonstration of efficacy is necessary.

Fe(ii)-Catalyzed alkenylation of benzylic C-H bonds with diazo compounds.

We report herein an alkenylation of benzylic C(sp3)-H bonds with diazo compounds via carbon cation intermediates with DDQ as the oxidant in the presence of a catalytic amount of Fe(ii). Diphenylmethane, toluene, benzyl methyl sulfide and their derivatives could be applied as substrates to afford the tetra-substituted olefin products, which may serve as useful building blocks in organic synthesis.

VpStyA1/VpStyA2B of Variovorax paradoxus EPS: An Aryl Alkyl Sulfoxidase Rather than a Styrene Epoxidizing Monooxygenase.

Herein we describe the first representative of an E2-type two-component styrene monooxygenase of proteobacteria. It comprises a single epoxidase protein (VpStyA1) and a two domain protein (VpStyA2B) harboring an epoxidase (A2) and a FAD-reductase (B) domain. It was annotated as VpStyA1/VpStyA2B of Variovorax paradoxus EPS. VpStyA2B serves mainly as NADH:FAD-oxidoreductase. A Km of 33.6 ± 4.0 µM for FAD and a kcat of 22.3 ± 1.1 s−1 were determined and resulted in a catalytic efficiency (kcat Km−1) of 0.64 s−1 μM−1. To investigate its NADH:FAD-oxidoreductase function the linker between A2- and B-domain (AREAV) was mutated. One mutant (AAAAA) showed 18.7-fold higher affinity for FAD (kcat Km−1 of 5.21 s−1 μM−1) while keeping wildtype NADH-affinity and -oxidation activity. Both components, VpStyA2B and VpStyA1, showed monooxygenase activity on styrene of 0.14 U mg−1 and 0.46 U mg−1, as well as on benzyl methyl sulfide of 1.62 U mg−1 and 3.11 U mg−1, respectively. The high sulfoxidase activity was the reason to test several thioanisole-like substrates in biotransformations. VpStyA1 showed high substrate conversions (up to 95% in 2 h) and produced dominantly (S)-enantiomeric sulfoxides of all tested substrates. The AAAAA-mutant showed a 1.6-fold increased monooxygenase activity. In comparison, the GQWCSQY-mutant did neither show monooxygenase nor efficient FAD-reductase activity. Hence, the linker between the two domains of VpStyA2B has effects on the reductase as well as on the monooxygenase performance. Overall, this monooxygenase represents a promising candidate for biocatalyst development and studying natural fusion proteins.

Effect of different irradiation dose treatment on the lipid oxidation, instrumental color and volatiles of fresh pork and their changes during storage

This study mainly investigated the effect of different doses irradiation (0, 3, 5 or 7kGy) on the quality changes of pork during 4°C storage by determining the irradiation off-odor intensity, thiobarbituric acid reactive substances (TBARs), fatty acid composition, volatiles and color of the samples during whole storage. The results showed that ≥7kGy irradiation could make the samples produce obvious irradiation off-odor. However, after 7days storage irradiation off-odor was reduced. Lipid oxidation was also promoted by irradiation. Benzyl methyl sulfide was produced newly and significantly increased (P<0.05) by irradiation. Fatty acids in pork samples decreased significantly with irradiation dose increase within the range of <7kGy, but significantly increased (P<0.05) in samples of 7kGy. Irradiation significantly increased the a* values regardless of storage time but had little effects on b* and L* values, and the increase of a* values was dose-dependent.

Substituent effects on the TiO2 photosensitized oxidation reaction of benzyl thioethers and thiols in deaerated acetonitrile

Abstract The TiO 2 photosensitized oxidation of benzyl methyl sulfides (X-C 6 H 4 CH 2 SCH 3 ) and benzyl thiols (X-C 6 H 4 CH 2 SH) has been investigated in Ar-saturated CH 3 CN. Steady-state irradiation produced benzaldehydes or dibenzylsulfides as oxidation products with sulfides and thiols, respectively. The results obtained through kinetic competitive experiments, aimed to evaluate the ring substituent effect on the reactivity, suggested the involvement of radical cation intermediates, formed by the favorable electron transfer from the substrate to the TiO 2 photogenerated hole, which reasonably deprotonate to give the final products. This process was poorly affected by the adsorption of the substrate at the TiO 2 surface, as demonstrated by similar results, both in terms of products and reactivity, collected for the homogeneous photooxidation of the same substrates sensitized by N -methoxyphenanthridinium hexafluorophosphate (MeOP + PF 6 − ). This behavior is likely due to the low hydrogen-bond acceptor ability of divalent sulfur systems. Density functional theory calculations pointed out that the most stable conformations of X-C 6 H 4 CH 2 SH + are characterized by having the C S bond almost collinear with the π system of the aromatic ring and by a significant charge and spin delocalization involving both the phenyl ring and the sulfur atom.

Biotransformation of prochiral sulfides into (R)-sulfoxides using immobilized Gordonia terrae IEGM 136 cells

Biotransformation of methyl phenyl sulfide (MPS) into optically active (R)-sulfoxide was optimized using Gordonia terrae IEGM 136 cells immobilized into cryogel of polyvinyl alcohol. Biotransformation time of 0.5g/L MPS was shortened from 144 to 24h in comparison with free cells. Immobilized Gordonia cells were resistant to high (up to 1.5g/L) sulfide concentrations and catalyzed its complete bioconversion into (R)-sulfoxide (95% ee) within 72h. Using a sequential addition method, the total load of MPS reached 4.25g/L. At that, MPS bioconversion was 96.9% and the enantiomeric excess (ee) value of the target (R)-sulfoxide was as high as 96%. Possible reuse of immobilized cells for MPS biotransformation was experimentally proved. The obtained biocatalyst showed a high activity towards ethyl phenyl sulfide, benzyl methyl sulfide, methyl p-tolyl sulfide and formed corresponding (R)-sulfoxides with 77–95% ee. Putative pathways for sulfide oxidation by Gordonia cells were proposed.

Photoinduced One-Electron Oxidation of Benzyl Methyl Sulfides in Acetonitrile: Time-Resolved Spectroscopic Evidence for a Thionium Ion Intermediate.

The photo-oxidation of 4-methoxybenzyl methyl sulfide (1a), benzyl methyl sulfide (1b), and 4-cyanobenzyl methyl sulfide (1c) has been investigated in the presence of N-methoxy phenanthridinium hexafluorophosphate (MeOP(+)PF6(-)) under nitrogen in CH3CN. The steady-state photolysis experiments showed for the investigated sulfides exclusively the formation of the corresponding benzaldehyde as the oxidation product, reasonably due to a deprotonation of the sulfide radical cations. Photo-oxidation of 1a-1c occurs through an electron transfer process. Indeed, laser flash photolysis measurements showed an efficient formation of sulfide radical cations, detected in their dimeric form [(4-X-C6H4CH2SCH3)2(+•)] at ≈520 nm. At longer delay times, the absorption of the dimer radical cation was replaced by an absorption band assigned to the (α-thio)benzyl cation (thionium ion, λmax = 420-400 nm), formed by oxidation of the benzyl radical and not by that of the (α-thiomethyl)benzyl radical, as expected if a Cα-H bond cleavage is operative. This finding highlights a particular stability of this kind of cation never reported before, even though its involvement in one-electron oxidation mechanisms of various sulfides has already been invoked. Density functional theory calculations allowed identification of a significant charge and spin delocalization involving both the phenyl ring and the sulfur atom of the radical cations.

Metal catalyzed cross-coupling of aryl and benzyl methyl sulfides: nickel catalyzed Caryl–Csp3 and Csp3–Csp3 bond formations

The nickel catalyzed functionalization of CAr–SMe and Csp3–SMe bonds by direct exchange of the sulfur atom with an activated sp3-carbon has been developed. The protocol allows the conversion of aryl and benzyl methyl sulfides to trimethylsilylated products in good yields.

Synthesis of N,P-, S,P-, P,P- and S,P,S-ligands using reactions of cyclopalladated complexes with KPPh2

Readily available air- and moisture-stable dimeric chloro-bridged CN-, CS- and CP-cyclopalladated complexes with the (sp2)C–Pd bond react with 4.5 equiv. of KPPh2 in THF to give the corresponding P,N-, P,S- and P,P-bidentate ligands in 35–63% yield. The phosphination method is applicable to five- and six-membered palladacycles derived from (S)-N,N-dimethyl-1-phenylethylamine, (S)-4-tert-butyl-2-phenyl-2-oxazoline, benzyl methyl sulfide, benzyldiphenylphosphine, 2-benzylpyridine and N,N-dimethylbiphenyl-2-amine. The reaction of 1.2 equiv. of KPPh2 with the SCS-pincer cyclopalladated complex obtained from 1,3-bis(methylthiomethyl)benzene provided the corresponding S,P,S-tridentate ligand in 49% yield.

Transcyclopalladation on silica gel

A possibility of transcyclopalladation on silica gel was shown using reactions of acetato- and chloro-bridged dimeric cyclopalladated complexes derived from N,N-dimethylbenzylamine with benzyl methyl sulfide, benzyl phenyl sulfide, benzyldiphenylphosphine, 8-methylquinoline and 1,3-bis(methylthiomethyl)benzene in the presence of equimolar amount of CF3CO2H. The reaction provided the corresponding C,S-, C,N-, C,P- and S,C,S-palladacycles in 39–65% yield.

Solvent-free direct cyclopalladation of sulfides on silica gel

Abstract Direct cyclopalladation of benzyl methyl sulfide, benzyl phenyl sulfide and 1,3-bis(methylthiomethyl)benzene using Pd(OAc)2 can be accomplished using silica gel instead of a solvent. The yields of the corresponding cyclopalladated complexes in these green transformations are very similar to those obtained using conventional solvent conditions. The X-ray crystallographic data for trans-Pd(HL)2Cl2 (HL = benzyl methyl sulfide) are reported.

Alloxazine–cyclodextrin conjugates for organocatalytic enantioselective sulfoxidations

Four structurally different alloxazine-cyclodextrin conjugates were prepared and tested as catalysts for the enantioselective oxidation of prochiral sulfides to sulfoxides by hydrogen peroxide in aqueous solutions. The alloxazinium unit was appended to the primary face of α- and β-cyclodextrins via a linker with variable length. A series of sulfides was used as substrates: n-alkyl methyl sulfides (n-alkyl = hexyl, octyl, decyl, dodecyl), cyclohexyl methyl sulfide, tert-butyl methyl sulfide, benzyl methyl sulfide and thioanisol. α-Cyclodextrin conjugate having alloxazinium unit attached via a short linker proved to be a suitable catalyst for oxidations of n-alkyl methyl sulfides, displaying conversions up to 98% and enantioselectivities up to 77% ee. β-Cyclodextrin conjugates were optimal catalysts for the oxidation of sulfides carrying bulkier substituents; e.g. tert-butyl methyl sulfide was oxidized with quantitative conversion and 91% ee. Low loadings (0.3-5 mol%) of the catalysts were used. No overoxidation to sulfones was observed in this study.

Kinetic Mechanism of Phenylacetone Monooxygenase from Thermobifida fusca

Phenylacetone monooxygenase (PAMO) from Thermobifida fusca is a FAD-containing Baeyer-Villiger monooxygenase (BVMO). To elucidate the mechanism of conversion of phenylacetone by PAMO, we have performed a detailed steady-state and pre-steady-state kinetic analysis. In the catalytic cycle ( k cat = 3.1 s (-1)), rapid binding of NADPH ( K d = 0.7 microM) is followed by a transfer of the 4( R)-hydride from NADPH to the FAD cofactor ( k red = 12 s (-1)). The reduced PAMO is rapidly oxygenated by molecular oxygen ( k ox = 870 mM (-1) s (-1)), yielding a C4a-peroxyflavin. The peroxyflavin enzyme intermediate reacts with phenylacetone to form benzylacetate ( k 1 = 73 s (-1)). This latter kinetic event leads to an enzyme intermediate which we could not unequivocally assign and may represent a Criegee intermediate or a C4a-hydroxyflavin form. The relatively slow decay (4.1 s (-1)) of this intermediate yields fully reoxidized PAMO and limits the turnover rate. NADP (+) release is relatively fast and represents the final step of the catalytic cycle. This study shows that kinetic behavior of PAMO is significantly different when compared with that of sequence-related monooxygenases, e.g., cyclohexanone monooxygenase and liver microsomal flavin-containing monooxygenase. Inspection of the crystal structure of PAMO has revealed that residue R337, which is conserved in other BVMOs, is positioned close to the flavin cofactor. The analyzed R337A and R337K mutant enzymes were still able to form and stabilize the C4a-peroxyflavin intermediate. The mutants were unable to convert either phenylacetone or benzyl methyl sulfide. This demonstrates that R337 is crucially involved in assisting PAMO-mediated Baeyer-Villiger and sulfoxidation reactions.

Solvent Effects on the Redox Properties of Thioethers

The one-electron reduction potential of the radical cations of thioanisole (1), benzyl methyl sulfide (2) and 2-hydroxyethyl benzyl sulfide (3) in water, formamide, acetonitrile, acetone, 1,1,1,3,3,3-hexafluoropropan-2-ol, methanol and 2-propanol was investigated by cyclic voltammetry. For comparison the one-electron reduction potentials in water were also measured using pulse radiolysis. The redox potential is strongly influenced by the nature of the solvent and the solvent sensitivity increases with charge localization. The present results have been used to evaluate solvent effects in view of the Kamlet-Taft relationship. The Kamlet-Taft expression quantitatively describes the solvent effects on the redox properties of 1-3 and gives the relative importance of the different solvent properties. The dominating contribution to the solvent effects is the solvent dipolarity/polarizability pi*, whereas alpha appears to be of minor importance. Furthermore, the relationship between the pi* and reduction potential of radical cations of 1-3 appear to be linear. It was also possible to find the same trend between the solvent dipole moment and peak potential of 1-3. These facts indicate that the nature of solvation is mainly nonspecific.

06/00538 Coal research in Newcastle — past, present and future: Gupta, R. P. Fuel, 2005, 84, (10), 1176–1188.

Two microbial strains (Brevibacterium sp. DO, Pseudomonas aeruginosa OS1) were isolated for their ability to desulfurize dibenzothiophene (DBT) and benzyl methyl sulfide (BMS). Enrichment was achieved by a sulfur-selective screening system using the model compounds as the sole source of sulfur for bacterial growth. Brevibacterium sp. DO utilizes DBT as a sole source of sulfur, carbon and energy for growth, whereas Pseudomonas aeruginosa OS1 metabolizes BMS to only a small extent under sulfur-selective conditions. Investigations of the regulation of enzymes involved in the desulfurization of coal-relevant sulfur compounds indicate that in nature at least two mechanisms exist: ‘carbon regulation’ and ‘sulfur regulation’. The biochemical mechanisms leading to the desulfurization of BMS and DBT are similar. The sulfur atom of both compounds is initially oxidized to the corresponding sulfone, and cleavage of the CS bond proceeds via the formation of a chemically unstable hemimercaptal (S-oxidized form) by oxidation of the carbon atom adjacent to the sulfur atom. These results indicate that oxidation of sulfur to its highest oxidation state may be the precondition for the oxidative cleavage of the covalent CS bonds. By isotope-labelling experiments using 18O2, the initial enzymes were identified as sulfoxygenases that use molecular oxygen. Cleavage of the CS bond of DBT and BMS leads to the formation of organic sulfinic acids as intermediates. With DBT the sulfinic acid is desulfurized probably by hydrolysis; this results in the formation of sulfite and benzoate. The desulfurization of BMS proceeds by sulfonic acid-oxidation. The applicability of these biochemical mechanisms to the microbial desulfurization of coal is discussed.

Facile Preparation of Trimethylsulfonium Bromide

Trimethylsulfonium bromide, utilized to make oxiranes and molten salts, has been reported to be prepared from dimethyl sulfoxide and ethyl bromoacetate, alkyl halide and dimethyl sulfide, and dimethyl sulfoxide and bromine. Herein, we report a very simple and convenient method of trimethylsulfonium bromide from a modified Kornblum oxidation condition. Typical Kornblum oxidation is referred to a reaction in which alkyl/aryl halide (tosylate) is reacted with dimethyl sulfoxide followed by a direct workup procedure in basic aqueous solution to prepare corresponding aldehyde (path 1 in Figure 1). However we have found that Kornblum oxidation in the absence of water and base afforded colorless crystalline trimethylsulfonium bromide in about 65% yields after recrystallization. The X-ray crystallographic and NMR data of trimethylsulfonium bromide were consistent with those of the published report. Several pathways can be envisaged for the formation of trimethylsulfonium bromide in our conditions. However we believe that a path 2 in Figure 1 could be a major route in our acidic conditions based on control experiments. We found out that volatile products (methyl bromide, dimethyl sulfide, and hydrogen bromide) were efficiently made in our conditions. That is, we were able to isolate a mixture of aniline hydrobromide and N-methylaniline which was formed in an aniline trap attached at the outlet of reflux condenser. In an another experiment we could observe and collect solid trimethylsulfonium bromide (about 1 gm) formed in a reservoir attached between the reaction flask and reflux condenser, which gave us an information that methyl bromide and dimethyl sulfide were obviously generating in an appreciable amount in our reaction conditions. Supposing a path 2 in Figure 1 to be a major route, then one might ask for the verification of benzyl methanesulfenate. We tried to get any evidence for the existence of benzyl methanesulfenate by both NMR and GC/MS, only to fail. We believe that benzyl methanesulfenate can not survive our acidic conditions. Instead we found out that benzyl methyl sulfide and dibenzyl sulfide were formed. In order to get more pieces of evidence related with this modified Kornblum oxidation reactions, reactions of benzyl bromide with diphenyl sulfoxide and methyl phenyl sulfoxide were carried out. As shown in Figure 2, reactions of benzyl bromide with either diphenyl sulfoxide and methyl phenyl sulfoxide turned out to be very clean by NMR. Trimethylsulfonium bromide was not formed at all in these reactions. Noteworthy was that further oxidation proceeded in reaction of diphenyl sulfoxide to give benzoic acid, instead of benzaldehyde obtained in the reaction of methyl phenyl Figure 1. Reaction of benzyl bromide and dimethyl sulfoxide.