The conversion of halogen-containing polymers to the corresponding hydroxyl derivatives

The direct conversion of poly(epichlorohydrin), poly[3,3-bis(chloromethyl)oxetane], and poly-(vinyl chloroethyl ether) to the corresponding hydroxyl-containing polymers is described. The replacement of the halogen atom in several chlorine-containing polymeric esters by an acetyl group and the subsequent conversion of the latter derivatives to hydroxyl-containing polymers is also described.     

The conversion of primary alcohols to the corresponding aldehydes by a modified lead tetraacetate oxidation

A novel metod for obtaining aldehydes in good yield from primary alcohols has been devised, using the combination lead tetraacetate—manganous diacetate as the oxidizing agent.     

Chlorotrimethylsilane-nitrate salts as oxidants: direct oxidative conversion of thiols and disulfides to sulfonyl chlorides

A mixture of nitrate salt and chlorotrimethylsilane is found to be a mild and efficient reagent for the direct oxidative conversion of thiols (1) and disulfides (2) to the corresponding sulfonyl chlorides (3) in excellent yields through oxidative chlorination. Sulfides and sulfoxides were also found to undergo oxidation to sulfones under similar reaction conditions. In most cases these reactions are highly selective, simple, and clean, affording products in high yield and purity.     

Nitrogen doped carbon catalyzing acetylene conversion to vinyl chloride

Commercial production of vinyl chloride from acetylene relies on the use of HgCl2as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vital to explore alternative catalysts without mercury. We report here that N-doped carbon can catalyze directly transformation of acetylene to vinyl chloride. Particularly, N-doped high surface area mesoporous carbon exhibits a rather high activity with the acetylene conversion reaching 77% and vinyl chloride selectivity above 98% at a space velocity of 1.0 mL min-1 g-1and 200 ℃. It delivers a stable performance within a test period of 100 h and no obvious deactivation is observed,demonstrating potentials to substitute the notoriously toxic mercuric chloride catalyst.     

Generation of trifluoromethyl thiolsulphonate through one-pot reaction of sulfonyl chloride and trifluoromethanesulfanylamides

A novel and efficient tandem reaction of sulfonyl chloride and trifluoromethylsulfanylamide is described here for the synthesis of various trifluoromethyl thiolsulphonates with a broad functional group tolerance. In the process, it is believed that sulfinate generated from sulfonyl chloride is a critical intermediate and the additive 4-methylbenzenesulfonic acid (p-TsOH) facilitates the formation of “CF₃S⁺”. Electrophilic trifluoromethylthiolation of in situ generated sulfinate and “CF₃S⁺” provides the final products.     

Pivaloyl chloride/DMF: a new reagent for conversion of alcohols to chlorides

An efficient procedure for conversion of alcohols into the corresponding chlorides is described. Pivaloyl chloride/DMF complex is employed as a mild and inexpensive reagent. A possible reaction mechanism is proposed.     

An expedient reductive method for conversion of ketoximes to the corresponding carbonyl compounds

A wide array of readily prepared pivalates of ketoximes can be converted to the corresponding ketones in good yields by treatment with iron powder in THF containing catalytic amounts of both trimethylsilyl chloride and glacial acetic acid at room temperature for 30 min, followed by a brief aqueous workup.     

Deprotection of trimethylsilyl ethers to corresponding alcohols promoted by silica chloride: a heterogeneous and eco-friendly protocol

Silica chloride as an efficient solid acid can serve as an eco-friendly and high-capacity reagent for the deprotection of trimethylsilyl ethers to their corresponding alcohols under mild and heterogeneous conditions. The yields are excellent and the procedure is simple and convenient, with the higher catalytic efficiency of a heterogeneous system.     

Fe(III) chloride catalyzed conversion of epoxides to acetonides

A mild and efficient method for the preparation of acetonides from epoxides catalyzed by iron(III) chlorides has been developed.     

The reaction of 2-(3-sydnonyl)phenylmethanol with sulfonyl chlorides. A one pot conversion to the chloro congener

The interesting transformation of 2-(3-sydnonylphenylmethanol ( 1 ) to its chloro congener 2 , in moderate to good yield using sulfonyl chlorides, is described. A mechanism for the transformation is suggested.     

Synthesis of spirocyclopropane carboxylic acids from flavanones and their conversion to the corresponding pyridazinones

The conversion of flavanones to spirocyclopropane carboxylic acids is reported. It has been shown that a mixture of three isomers is formed. Their structure and configuration have been elucidated from PMR data. Substituted pyridazinones were obtained from the synthesized acids.T. G. Shevchenko University, Kiev 252017. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 616-623, May, 1995. Original article submitted March 17, 1995.     

A new and efficient conversion of olefins into thiiranes using diethoxyoxophosphoranesulfenyl chloride

An expedient synthesis of thiiranes is described that involves electrophilic addition of diethoxyoxophosphoranesulfenyl chloride to alkenes followed by fluoride anion promoted conversion of the intermediate adducts into thiiranes. © 1997 John Wiley & Sons, Inc. Heteroatom Chem 8: 429–433, 1997     

改性H-ZSM-34上氯甲烷催化转化制低碳烯烃

比较了几种典型的沸石分子筛在氯甲烷转化制乙烯、丙烯和丁烯等低碳烯烃反应中的催化性能, 发现H-ZSM-34具有较佳的催化活性和选择性. 经乙二胺四乙酸二钠(Na₂H₂EDTA)水溶液处理, 并经离子交换及焙烧后, H-ZSM-34上氯甲烷转化制低碳烯烃的催化性能显著改善. 当Na₂H₂EDTA浓度为0.1 mol/L, 反应温度为673 K, CH₃Cl分压9.2 kPa时, C₂-C₄烯烃选择性和收率分别达82%和61%. 研究还发现, Ce修饰H-ZSM-34催化剂同样可改善氯甲烷制低碳烯烃的选择性和收率. 表征结果表明, Na₂H₂EDTA处理和Ce修饰均降低了H-ZSM-34的酸性. 酸性的降低可抑制低碳烯烃的氢转移反应, 继而避免了其进一步转化为低碳烷烃.     

Simple synthesis of 1-substituted-4-vinyl-1,2,3-triazoles based on polystyrene-supported sulfonyl chloride

Polystyrene-supported but-3-ynyl sulfonate reagent has been developed and applied to the traceless solid-phase organic synthesis of 1-substituted-4-vinyl-1,2,3-triazoles by CuI-promoted 1,3-dipolar cycloaddition reaction with various organic azides and subsequent cleavage from the polymer support through elimination reaction mediated by 1.8-diazabicyclo[5,4,0]undec-7-ene (DBU). The advantages of this new synthetic method include simple operation and moderate to good yields of the products, as well as good stability of the reagent.     

Kinetic study on the conversion of pyridine- and quinolinecarboxylic acids to the corresponding trichloromethyl compounds

The reaction rates of the conversion of various substituted picolinic and quinaldinic acids to the corresponding trichloromethylpyridines and quinolines by treatment with phosphorus pentachloride in refluxing thionyl chloride have been measured, and the apparent second-order kinetic constants determined. The logarithmic rate constants (log k) were found to be linear with the basicities (pKa) of the unsaturated ring nitrogens in the substrates. The reaction constant, p, of the conversion was estimated.     

Branching generation during the free radical copolymerization of p-vinyl benzene sulfonyl chloride with styrene

The branching generation during the free radical copolymerization of chain transfer monomer p-vinyl benzene sulfonyl chloride (VBSC) with styrene was investigated by a simple mathematic model. Chain transfer constant of VBSC was determined to be around 0.3 by fitting the ¹H-NMR monitored experimental results with a mathematic model. According to the theoretical analysis, the obtained poly(VBSC) and its copolymers were substantiated to have a grafting-like main chain with residual pendent sulfonyl chloride groups after consuming most of the vinyl groups. The copolymerization results of VBSC with styrene at varied feed ratios demonstrated that conversion of sulfonyl chloride groups was lower than that of the monomer, which was in agreement with the theoretical results. The glass transition temperature, number average molecular weight and distribution of those obtained polymers were primarily investigated. Comparing with other chain transfer monomers, VBSC has a chain transfer constant much closer to unity therefore a more branched polymer is expected. Additionally, the branched polystyrene with residual sulfonyl chloride groups is hopefully to be further used as ATRP macroinitiators or reactive intermediates to synthesize functional polymers with complex structure.     

Theoretical investigation of internal conversion in chromyl chloride

The internal conversion process from single vibronic levels in the first excited electronic state S₁ of chromyl chloride was theoretically investigated. On the basis of this analysis certain important features of the experimentally observed fluorescence decay from S₁ have been understood. Implications of the obtained results to multiphoton chemistry are discussed.