Transformation of β-chalcogeno alkenylboranes into tetrasubstituted olefins

In view of generating trisubstituted vinylic chalcogen derivatives, β-chalcogeno alkenylboranes generated through the chalcogen electrophile induced rearrangements of 1-alkynyltrialkyl borates have been subjected to Suzuki-Miyaura coupling and to boron to copper transmetalation followed by alkylation. Some of the trisubstituted vinyl sulfides obtained by this latter strategy have been converted efficiently into the title olefins through the NiCl₂(dmpe) catalyzed coupling with various Grignard reagents.     

Olefin epoxidation with hydrogen peroxide catalyzed by lacunary polyoxometalate [gamma-SiW10O34H2O2]4-

The tetra-n-butylammonium (TBA) salt of the divacant Keggin-type polyoxometalate [TBA](4)[gamma-SiW(10)O(34)(H(2)O)(2)] (I) catalyzes the oxygen-transfer reactions of olefins, allylic alcohols, and sulfides with 30 % aqueous hydrogen peroxide. The negative Hammett rho(+) (-0.99) for the competitive oxidation of p-substituted styrenes and the low value of (nucleophilic oxidation)/(total oxidation), X(SO)=0.04, for I-catalyzed oxidation of thianthrene 5-oxide (SSO) reveals that a strongly electrophilic oxidant species is formed on I. The preferential formation of trans-epoxide during epoxidation of 3-methyl-1-cyclohexene demonstrates the steric constraints of the active site of I. The I-catalyzed epoxidation proceeds with an induction period that disappears upon treatment of I with hydrogen peroxide. (29)Si and (183)W NMR spectroscopy and CSI mass spectrometry show that reaction of I with excess hydrogen peroxide leads to fast formation of a diperoxo species, [TBA](4)[gamma-SiW(10)O(32)(O(2))(2)] (II), with retention of a gamma-Keggin type structure. Whereas the isolated compound II is inactive for stoichiometric epoxidation of cyclooctene, epoxidation with II does proceed in the presence of hydrogen peroxide. The reaction of II with hydrogen peroxide would form a reactive species (III), and this step corresponds to the induction period observed in the catalytic epoxidation. The steric and electronic characters of III are the same as those for the catalytic epoxidation by I. Kinetic, spectroscopic, and mechanistic investigations show that the present epoxidation proceeds via III.     

The application of nanostructured transition metal sulfides as anodes for lithium ion batteries

With wide application of electric vehicles and large-scale in energy storage systems, the requirement of secondary batteries with higher power density and better safety gets urgent. Owing to the merits of high theoretical capacity, relatively low cost and suitable discharge voltage, much attention has been paid to the transition metal sulfides. Recently, a large amount of research papers have reported about the application of transition metal sulfides in lithium ion batteries. However, the practical application of transition metal sulfides is still impeded by their fast capacity fading and poor rate performance. More well-focused researches should be operated towards the commercialization of transition metal sulfides in lithium ion batteries. In this review, recent development of using transition metal sulfides such as copper sulfides,molybdenum sulfides, cobalt sulfides, and iron sulfides as electrode materials for lithium ion batteries is presented. In addition, the electrochemical reaction mechanisms and synthetic strategy of transition metal sulfides are briefly summarized. The critical issues, challenges, and perspectives providing a further understanding of the associated electrochemical processes are also discussed.     

Electrolytic partial fluorination of organic compounds: 89: Regioselective anodic fluorination of tetrazolyl sulfides

Anodic fluorination of five-membered nitrogen-containing heterocyclic sulfides like tetrazolyl sulfides was comparatively studied. The anodic fluorination of tetrazolyl sulfides having α-electron-withdrawing groups was successfully carried out to provide α-monofluorinated tetrazolyl derivatives in moderate yields. This is in sharp contrast to the low efficient anodic fluorination of triazolyl sulfides. Thus, it was found that the efficiency of anodic fluorination is greatly affected by the basicity of the heterocyclic groups of the starting heterocyclic sulfides.     

稀土硫化物的合成及应用研究进展

稀土硫化物作为环保颜料和热电材料被广泛研究和应用,已成为材料科学领域的研究热点之一。目前主要可通过直接合成法、微波法、还原法这三种方法来合成稀土硫化物。总结了稀土硫化物制备方法的研究进展,讨论了其优缺点。同时讨论了一些稀土硫化物的热电性质和作为颜料的应用。结合本课题组在稀土硫化物方面的研究工作,对稀土硫化物的制备方法和应用的发展方向进行了展望。     

Reaction of arylthiacyclanylsulfonium salts with nitrogen bases

When arylthiacyclanylsulfonium salts are heated with nitrogen bases the C-S bond of the heteroring undergoes quantitative cleavage and the base adds to form a C-N bond. These sulfonium salts react with ammonia or pyridine to give ammonioalkyl sulfides; amino sulfides and secondary amine salts are obtained with excess secondary amines. The described reaction is a new preparative method for the synthesis of amino sulfides and ammonioalkyl aryl sulfides.     

Regioselective synthesis of quinolone-annulated sulfur heterocycles by aryl radical cyclization

The tin hydride-mediated cyclizations of a number of sulfides and sulfones under mild, neutral conditions, have been investigated accompanied by some amount of β-scission product for sulfides. The sulfides were derived from 4-mercaptoquinolone and 2-bromobenzyl bromides by phase transfer catalyzed reaction and the corresponding sulfones were prepared by treatment of the sulfides with m-CPBA at room temperature. The sulfides and the corresponding sulfones were then reacted with ⁿBu₃SnH-AIBN to give regioselective quinolone-annulated sulfur heterocycles.     

Preparation of bromodifluoromethyl sulfide and its conversion to trifluoromethyl sulfide

Bromodifluoromethyl sulfides are prepared by the reaction of mercaptides with CF₂BrX (x=Br,Cl). And treatment of bromodifluoromethyl sulfides with various inorganic fluorides produced trifluoromethyl sulfides.     

联二烯丁基硫醚衍生物合成呋喃的反应

本文报道以联二烯丁基硫醚为起始物的呋喃衍生物的合成方法.实验结果表明,β-联二烯丁基硫醚醇在氢化钠的作用下以很高的收率环化生成一个苯硫基离去的呋喃产物,β-联二烯丁基硫醚醛与外加亲核试剂作用后能得到多一个取代的类似呋喃产物,而β-联二烯丁基硫醚酮在P2O5的促进下也能环化生成呋喃衍生物.     

Traceless solid-phase synthesis of multiple sulfonamide-containing cyclic sulfides exploiting microwave irradiation

In this Letter, a new synthetic method of sulfonamide-containing cyclic sulfides using a microwave-assisted traceless solid-phase approach is described. Using this new method, many highly pure cyclic sulfides were efficiently synthesized based on intramolecular alkylation of the sulfides followed by elimination of the desired products from the generated sulfonium salts.     

金属催化硫醚的不对称氧化研究进展

手性金属络合物催化硫醚的不对称氧化是合成手性亚砜最有效的方法. 理性设计各种手性金属络合物催化剂应用于催化对映选择性氧化潜手性硫醚反应中, 近年来引起了化学家们较大的关注. 综述了各类手性金属络合物催化剂在硫醚不对称氧化中的应用.     

Enhancing the efficiency of using electroplated iron and cobalt sulfides with a sublayer of NiC composite in a lithium battery

The efficiency of using in a lithium battery transition metal sulfides electroplated on a metal support strongly depends on the kind and relief of the support. To make the nickel support rougher for enhancing the adhesion of sulfides, it was electroplated with a nickel–carbon composite, NiC. The discharge capacity and the efficiency of cycling of iron and cobalt sulfides electroplated with a NiC sublayer were higher than in the case when the sulfides were electroplated on a smooth nickel support without composite coating.     

Pd‐NHC‐Catalyzed Alkynylation of General Aryl Sulfides with Alkynyl Grignard Reagents

Cross‐coupling reactions of unactivated aryl sulfides with alkynylmagnesium chloride have been invented to afford 1‐aryl‐1‐alkynes with the aid of a palladium/N‐heterocyclic carbene complex. This reaction has by far the widest scope of all transformations utilizing aryl sulfides and alkynes, while known cross‐coupling alkynylations of aryl‐sulfur electrophiles require activated azaaryl sulfides, thiolactams, or arenesulfonyl chlorides. The alkynylation of aryl sulfides is compatible with typical protecting functional groups. The alkynylation is applied to the synthesis of benzofuran‐based fluorescent molecules by taking advantage of characteristic organosulfur chemistry.     

1-Butadienyl Sulfide Polymerization

1-Butadienyl sulfides, mainly cis in configuration, are obtained by the base-catalyzed addition of mercaptans to vinylacetylene. bis-1-Butadienyl sulfides are readily polymerizable using azo catalysts, but mono-1-butadienyl sulfides are not, nor do they copolymerize with styrene or butadiene. They have a high Q-value and copolymerize well with other high Q monomers such as chlorostyrene and chloroprene. bis-1-Butadienyl sulfides were made by reacting a dithiol, such as bis-4-mercaptophenyl ether, with vinylacetylene or by a two-step process using mercaptoethanol followed by treatment of 2-hydroxyethylthiobutadiene with diisocyanate. The polymers were largely of 1,4-trans polydiene structure.     

Molecular vibrations and force fields of alkyl sulfides—XIV. Infrared spectra of ethyl isopropyl,propyl isopropyl,butyl isopropyl and diisopropyl sulfides

Infrared spectra of ethyl isopropyl and propyl isopropyl sulfides were examined in the liquid and glassy states, and those of butyl isopropyl and diisopropyl sulfides were observed in the liquid and crystalline solid states. The spectra observed were assigned. Normal coordinates were treated. We have then discussed on the rotational isomers and molecular conformations for these sulfides.     

Organische Phosphorverbindungen XXV Darstellung und Eigenschaften von sekundären und tertiären Phosphinsulfiden

Two new processes for the preparation of sec. phosphine sulfides which involve reaction of dialkylamino-dialkyl or diaryl phosphines with hydrogen sulfide, and of dialkylthionophosphonates, (RO)₂P(S)H, with GRIGNARD or organolithium reagents, respectively, are described. The addition of sec. phosphine sulfides to olefins and the condensation of sec. phosphine sulfides with N-hydroxymethyldialkylamines are reported. The conversion of tert. Phosphine sulfides to the corresponding tert. phosphine oxides is readily achieved with hydrogen peroxyde. The physical properties of several new unsymmetrical tert. phosphine sulfide and oxides are listed.     

Homocouplings of Sodium Arenesulfinates: Selective Access to Symmetric Diaryl Sulfides and Diaryl Disulfides

Symmetrical diaryl sulfides and diaryl disulfides have been efficiently and selectively constructed via the homocoupling of sodium arenesulfinates. The selectivity of products relied on the different reaction systems: symmetrical diaryl sulfides were predominately obtained under the Pd(OAc)₂ catalysis, whereas symmetrical diaryl sulfides were exclusively yielded in the presence of the reductive Fe/HCl system.     

The first broad application of alkynyl sulfides as dienophiles in cobalt(I)-catalyzed Diels-Alder reactions

The cobalt(I)-catalyzed Diels-Alder reaction of nonactivated aryl alkynyl sulfides with acyclic 1,3-dienes generates dihydroaromatic vinyl sulfides under very mild reaction conditions, and these products can be oxidized with mild oxidants to the corresponding diaryl sulfides in good overall yields. The steric and electronic effects of substituents on the aryl, as well as on the alkynyl, moieties of the aryl alkynyl sulfide are discussed. While the cobalt catalyst system is quite efficient in converting alkynyl sulfides to the Diels-Alder adducts, the transformation of the corresponding aryl alkynyl sulfoxides and sulfones under similar mild reaction conditions gave only moderate yields of the desired adducts.     

Green Procedure for the Synthesis of β-Nitro Sulfides by Michael Addition of Thiols to Nitroolefins

Michael addition of thiols to nitroolefins was carried out in water at room temperature without any catalyst, and β-nitro sulfides were obtained in excellent yields. This is the first example of Michael addition of thiols to nitroolefins in water without use of any catalyst. It provides a highly efficient, general, and practical green route to synthesis of β-nitro sulfides. Twenty-four new β-nitro sulfides were synthesized using this technique.