Alkyl Sulfides Research Articles

Manganese- and Lanthanide-Based 1D Chiral Coordination Polymers as an Enantioselective Catalyst for Sulfoxidation.

The chiral 1D-coordination polymers (CP) {[Ln2(MnLCl)2(NO3)2(dmf)6(H2O)2]·xH2O}n [Ln = Pr (1), Nd (2), Sm (3), and Gd (4)] were synthesized by the reaction of N,N'-bis(4-carboxysalicylidene)cyclohexanediamine (H4L) with [MnCl2·4(H2O)] and [Ln(NO3)3·x(H2O)] in the presence of dmf/pyridine at 90 °C. The polymers consist of manganese-salen-based moieties having carboxylate linkers connected to rare earth atoms in a 1D-chain structure. The polymers are very easily accessible. A one-step synthesis for the ligand and a second step for the preparation of the 1D coordination polymers starting from commercially available material are needed. The solid state structures of 1-4 were established by single-crystal X-ray diffraction. Compounds 1-4 were investigated as heterogeneous catalysts for the sulfoxidation reaction of various alkyl and aryl sulfides. The influence of various solvents and oxidizing agents on the catalytic reaction was examined. It was found that the catalysts were active for more than one reaction cycle without significant loss of activity. For phenylsulfide with 1 mol % of the catalyst 4, a maximum conversion 100% and a chemoselectivity 88% were observed.

Trifluorination of sulfides and dithioketals using IF5-pyridine-HF

Abstract Stable fluorinating reagent, IF5-pyridine-HF, was used for the polyfluorination of aryl alkyl sulfides. The introduction of three fluorine atoms with a concomitant migration of the arylsulfanyl group was achieved. Carrying out the reaction at 80 °C and presence of a methyl substituent on the aryl group were found to be effective for the polyfluorination. Trifluorinated products were also obtained from dithioketals by reaction with IF5-pyridine-HF. Tetrafluorination of phenyl benzyl ketone and dibenzyl ketone dithioketals was also achieved by reaction with IF5-pyridine-HF and Et3N-6HF.

ChemInform Abstract: Palladium and Copper Co‐Catalyzed Markovnikov Hydrothiolation of Terminal Olefins and Alkynes.

AbstractThe title reaction allows the synthesis of a wide variety of alkyl and vinyl sulfides.

ChemInform Abstract: One‐Pot Odorless Thia‐Michael Reaction by Copper Ferrite Nanoparticle‐Catalyzed Reaction of Elemental Sulfur, Aryl Halides and Electron‐Deficient Alkenes.

AbstractAryl alkyl sulfides are synthesized from the title reaction.

Carbon–sulfur bond reductive coupling from a platinum(ii) thiolate complex

Complex 1 was reacted with different alkyl halides at room temperature. This reaction proceeded via formation of binuclear intermediate complex 3 and through C–S bond reductive coupling to produce alkyl sulfides and corresponding halide complexes 2.

Direct α-acyloxylation of organic sulfides with the hypervalent (diacyloxyiodo)benzene/tetra-n-butylammonium bromide (TBAB) reagent combination

A novel metal-free approach to directly synthesize α-acyloxy sulfides from readily available alkyl sulfides utilizing hypervalent (diacyloxyiodo)benzene and TBAB reagent combination was developed.

ChemInform Abstract: Copper‐Catalyzed Regioselective C‐5 Sulfenylation of Imidazo[2,1‐b]thiazoles with Thiols.

AbstractVarious heterocyclic substrates as well as alkyl and (het)aryl sulfides including disulfide (IV) are used in the preparation of the target compounds which are of interest in pharmaceutical chemistry and material science.

ChemInform Abstract: B(C6F5)3‐Catalyzed Hydrodesulfurization Using Hydrosilanes — Metal‐Free Reduction of Sulfides.

AbstractThe method is highly chemoselective and applied to the reduction of a wide range of sulfides, including benzyl and alkyl sulfides, and dithianes.

Validation of a High-Performance Liquid Chromatography Photo-Diode Array Method for the Temperature Effects on Alk(En)yl Sulfides in Garlic Extracts

A sensitive analytical method employing a high-performance liquid chromatography photo-diode array system for the determination of allicin and alk(en)yl sulfides, including the diallyl, allyl methyl, and dimethyl sulfide series, was developed and validated. The method was evaluated in terms of linearity, limit of detection, limit of quantification, precision, and accuracy, and exhibited excellent linearity for all the analytes (R > 0.999). The intra-day and inter-day precision of the method was expressed as the relative standard deviation for each analyte and ranged from 0.17 to 3.75% and 0.53 to 10.83%, respectively. The recovery tests ranged from 85.89 to 106.99% for allicin and alk(en)yl sulfides, respectively. Using the developed analytical method, the changes in the allicin and alk(en)yl sulfide contents of garlic extracted obtained with different solvents were evaluated over one month of storage at 4 and 25°C. The allicin in the garlic extracts was found to be stable at 4°C, but relatively unstable at 25°C. The alk(en)yl sulfide content of the extracts increased continuously at 25°C, but much more slowly at 4°C. The results of our study suggest that our method may be useful in controlling the quality and clinical applications of processed garlic and its products.

ChemInform Abstract: Bimetallic Titanium Complex Catalyzed Enantioselective Oxidation of Thioethers Using Aqueous H2O2 as a Terminal Oxidant.

A series of dimeric amino alcohol derived Schiff bases with various chiral amino alcohols and their corresponding bimetallic titanium complex were generated in situ. Thereafter with the in situ generated complexes, the asymmetric oxidation of prochiral aryl alkyl sulfides has been investigated using aqueous H2O2 as a terminal oxidant. During the study we found that the use of methanol or tert-butanol as an additive improved the catalytic activity in terms of both conversion and enantioselectivity. Moreover we observed a co-operative effect of the two reactive units of the bimetallic complex, which results in high reactivity as well as enantioselectivity compared to the corresponding monomeric complex. With this improved catalytic system several aryl alkyl sulfides and 1,3-dithianes were oxidised to the corresponding sulfoxides with good to high enantioselectivity (ee 78–99%) and conversion (70–99%). Unlike the monomer, oxidation of substrates like benzyl phenyl sulfide was achieved with high enantioselectivity as well as high yield.

Palladium and copper co-catalyzed Markovnikov hydrothiolation of terminal olefins and alkynes

A simple and efficient method for palladium and copper co-catalyzed Markovnikov hydrothiolation of thiols to olefins or alkynes has been developed. The reaction allows olefins or alkynes bearing various functional groups to react with different thiols, providing good to excellent yields of alkyl sulfides or vinyl sulfides. A proposed mechanistic study indicated that Cu(II) plays a key role in obtaining Markovnikov products.

ChemInform Abstract: A Novel and Efficient Zinc‐Catalyzed Thioetherification of Aryl Halides.

AbstractA variety of aryl and alkyl sulfides are obtained via C—S cross‐coupling reaction of aryl halides with both aryl and alkyl thiols using ZnEt2/L‐proline as easily available, cheap, and environmentally benign catalytic system.

B(C6F5)3-Catalyzed Hydrodesulfurization Using Hydrosilanes--Metal-Free Reduction of Sulfides.

B(C6F5)3-catalyzed hydrodesulfurization of carbon-sulfur bonds was achieved using triethylsilane as the reducing agent. The corresponding products were obtained in good yields under mild reaction conditions. This protocol could be applied to the reduction of sulfides, including benzyl and alkyl sulfides and dithianes, with high chemoselectivities.

Synthesis of α-methylene propellanone via the strategic employment of metal-mediated cyclisation chemistry

Biologically active α-methylenene propellanone has been synthesised in 12 steps in an overall yield of 11%. The key step of the synthesis, an intramolecular Pauson–Khand reaction, proceeds in good yield under alkyl sulfide promotion conditions, to furnish the 5,5-fused moiety within the target. Samarium diiodide-induced intramolecular conjugate addition onto the resulting cyclopentenone was used to complete the intriguing [3.3.3] propellanone skeleton.

Refractive index changes in polyacrylates bearing alkyl sulfur groups through the sulfur oxidation reaction

Four polyacrylates with sulfur-containing side chains were prepared to examine the changes in refractive index (RI) induced by sulfur oxidation. Linear alkyl sulfides and alicyclic sulfides, such as 1,3-dithiolane and 1,4-dithiane, were introduced to impart large RIs to polyacrylates. Oxidation of the sulfur polymers by O3 and m-chloroperoxybenzoic acid led to the formation of the corresponding sulfoxide and sulfone polymers, respectively. Sulfur oxidation occurred completely, which was highlighted by the oxidized polymer exhibiting a refractive index comparable to a polymer that was synthesized using a sulfone monomer. The RI of the linear sulfur polymer increased and decreased due to the formation of sulfoxide and sulfone polymers, respectively. The Abbe number of the polymer with a linear sulfide side chain was 33.4, which increased to 48.7 after oxidation.

ChemInform Abstract: Palladium‐Catalyzed Direct Thiolation of Ethers with Sodium Sulfinates.

AbstractA new, simple, and mild method for the synthesis of aryl alkyl sulfides from ethers and sodium sulfinate is developed.

ChemInform Abstract: I2‐Catalyzed Oxidative C(sp3)—H/S—H Coupling: Utilizing Alkanes and Mercaptans as the Nucleophiles.

AbstractAn oxidative C(sp3)—H/S—H coupling of alkanes with mercaptans employing cheap and nontoxic I2 and 2,6‐di‐tert‐butylpyridine to afford aryl alkyl sulfides in moderate to good yields is developed.

A novel and efficient zinc-catalyzed thioetherification of aryl halides

The first Zn-catalyzed protocol for C–S cross-coupling reactions for the synthesis of substituted aryl and alkyl sulfides with good yields under mild reaction conditions is described.

Carbon nanotubides: an alternative for dispersion, functionalization and composites fabrication.

In this review, we systematically describe the state-of-knowledge in the area of carbon nanotubides (CNTDs). CNTDs can be used for achieving highly concentrated dispersions of SWCNTs and can also be used as an important intermediate for covalent chemical modification. In recent years, researchers have used SWCNTDs as starting materials for the functionalization of SWCNTs with functionalities such as alkyl chains, carboxylic acids, sulfide, amino, hydroxyl, silyl, bromide, ethers, ketones and polymers. Also, we discussed the observed selectivity on the covalent functionalization towards certain classes of CNTs. Finally, we describe the use of SWCNTDs in the manufacture of fibers, films and other functional materials.

One-pot Metal-free Synthesis of Benzyl Alkyl Sulfides

GRAPHICAL ABSTRACT