Influence of structure of alkenes on their retention on different stationary phases

Summary Retention indices of different alkenes are correlated with connectivity and topological parameters. The appropriate statistically valid relations hips are derived and discussed.     

Catalyst-free fluorinative alkoxylation of alkenes

The fluorinative alkoxylation of simple alkenes under catalyst-free conditions was achieved. Various substituted olefins, including terminal and internal alkenes, and oxygen-containing nucleophiles were compatible with the standard conditions, and gave a variety of β-fluoroethers in good to excellent yields. Notably, the alkynyl and chloride-containing nucleophiles were well tolerated. In addition, acetic acid and TsNH₂ could be also used as nucleophiles and successfully afforded the desired products in good yields.     

烯烃在USY沸石表面上化学反应热的量热测定

1.前言 在多相催化研究工作中,测定反应物分子在固体催化剂表面上化学吸附时产生的反应热,或者说化学吸附热,对研究催化剂的性质和反应物的表面化学反应都很有帮助。但是目前尚无有效的方法测定它。本文用吸附量热法测定了烯烃在USY沸石表面的吸附热,并提出了一种化学吸附热的估算方法。     

Reactivity in the upper limits of the reduction potential in solution: arene dianion intermolecular carbolithiation of alkenes

Lithium salts of dianions derived from arenes of high reduction potential (biphenyl, naphthalene) can carbometallate terminal alkenes (propene, isobutene) in an intermolecular fashion, affording partially dearomatized alkylated aryl anions, which are susceptible to further functionalization by electrophilic capture. This form of reactivity, specific of the arene dianion, deviates from the typical alkali metal-like reactivity displayed by these complexes, affording in most cases regio- and stereocontrolled products. Simple semiempirical calculations (PM3) help predicting the regiochemical outcome of this reaction, where some of the most inexpensive organic starting materials are involved.     

Selective reduction of alkenes, α,β-unsaturated carbonyl compounds, nitroarenes, nitroso compounds, N,N-hydrogenolysis of azo and hydrazo functions as well as simultaneous hydrodehalogenation and reduction of substituted aryl halides over PdMCM-41 catalyst under transfer hydrogen conditions

Chemoselective reductions of alkenes, α,β-unsaturated carbonyl compounds, nitro and nitroso compounds, N,N-hydrogenolysis of azo and hydrazo functions as well as simultaneous reduction and hydrodehalogenation of substituted aryl halides, including bulkier substrates, were achieved by catalytic transfer hydrogenation (CTH) using mesoporous PdMCM-41 catalyst. The yields were practically unaffected upon recycling of the catalyst. Further, the CTH process is accomplished without affecting the reduction of any other reducible functional group.     

分子筛担载金催化剂催化烯烃环氧化制环氧化合物

烯烃的环氧化是工业上的重要反应之一，在众多的烯烃中，端烯尤其是直链端烯是相对较难氧化的一类。     

Utilization of microwave heating in the McMurry reaction for facile coupling of aldehydes and ketones to give alkenes

Microwave heating was applied in high-yield syntheses of alkenes by McMurry coupling of aldehydes and ketones with low-valent titanium. All aldehydes and ketones including sulfur end-capped analogues gave alkenes in isolated yields above 80% without detectable amounts of pinacols.     

Co-immobilized formate anion and palladium on a polymer surface: a novel heterogeneous combination for transfer hydrogenation

A novel heterogeneous combination of a formate reagent and palladium catalyst co-immobilized on a resin support has been developed and shown to be highly efficient and recyclable for transfer hydrogenation of alkenes, imines, nitroarenes and 1,2-dicarbonyl compounds.     

An Improved Synthesis of Vinyl- and β-Iodovinyl Sulfones by a Molecular Iodine-Mediated One-Pot Iodosulfonation-Dehydroiodination Reaction

An improved one-pot method to synthesize vinyl sulfones from unsaturated systems by using molecular iodine/sodium arenesulfinate/sodium acetate as reagents was described. Vinyl sulfones derived from styrene derivatives were generally obtained in good to excellent yields except for those bearing strong electron releasing substituent. Aliphatic alkenes and activated alkenes gave the corresponding vinyl sulfone products in moderate to good yields. Arylacetylenes yielded the respective β-iodovinyl sulfones in good yields while low yield was observed with aliphatic terminal alkyne. The potentials of the method entail simplicity, short reaction time, non-anhydrous reaction conditions, employing inexpensive, non-metallic reagent and integrating two reactions that are commonly accomplished separately into a single operation.

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