addition–elimination of Grignard reagents to electron-rich ketones, such as methoxy substituted acetophenones, propiophenone and chromanone in a one-pot process, and that it has an enhancing effect on the addition of these reagents to the ketones. It has also been found that the reactions are highly stereoselective towards one regioisomer of the alkene in the case of oxygenated aryl-alkyl substituted substrates, but
Supported phosphotungstic acid catalyst on modified activated carbon for Friedel–Crafts alkenylation of diverse aromatics to their corresponding α-arylstyrenes
作者:Zhongkui Zhao、Xianhui Wang
DOI:10.1016/j.apcata.2015.07.007
日期:2015.8
The 100% conversion of phenylacetylene with 95.7% selectivity towards α-(2,5-dimethylphenyl) styrene can be achieved over the developed 30 wt.% PTA/AC catalyst under optimized reaction conditions, and no visible loss in catalytic performance can be observed after it suffers from several times recycling. The various characterization techniques including X-ray diffraction, N2 adsorption–desorption, Fourier
Supported phosphotungstic acid catalyst on mesoporous carbon with bimodal pores: A superior catalyst for Friedel-Crafts alkenylation of aromatics with phenylacetylene
作者:Zhongkui Zhao、Xianhui Wang
DOI:10.1016/j.apcata.2016.08.028
日期:2016.9
of 2.67% of the 35% PTA/MC solid acidcatalyst. It is also found that catalytic properties of the solid acids are strongly depended on acidic properties that affected by the textural properties of supports and PTA loading, as well as the accessibility of active sites affected by specific surface area and pore structure of catalyst. Moreover, the 35 wt.% PTA/MC catalyst has demonstrated outstanding catalytic
One-pot synthesis of oligomeric aryl-substituted PPV analogs with extended π-conjugation
作者:Ben-Ami Feit、Ludmila Buzhansky
DOI:10.1039/a905710b
日期:——
A conceptually novel approach for a stepwise one-pot synthesis of oligomeric poly(phenylvinylene) (PPV, â[C6H4âCHCH]â) analogs with extended Ï-conjugation of the type Hâ[CHC(Ar)âC6H4âC(Ar)CH]nâH (n = 2, 4), from the corresponding dienic monomers (n = 1), has been studied. The oligomerizations were performed in high yields by repeating the sequential preparation of the mercuric trifluoroacetate derivative Hâ[CHC(Ar)âC6H4âC(Ar)CH]nâHgCO2CF3 (n = 1, 2) and its coupling in the presence of PdCl2. The feasibility of this approach was demonstrated by a one-pot preparation of several tetramers, directly from the corresponding monomers.
我们研究了一种概念新颖的方法,即从相应的二元单体(n =  1)一步法合成具有 Hâ[CHC(Ar)âC6H4âC(Ar)CH]nâH (n =  2、4)型扩展Ï-共轭的低聚聚聚苯乙烯(PPV,â[C6H4âCHCH]â)类似物。通过重复三氟乙酸汞衍生物 Hâ[CHC(Ar)âC6H4âC(Ar)CH]nâHgCO2CF3 (n = 1, 2)的连续制备及其在 PdCl2 存在下的偶联,以高产率实现了低聚物化。这种方法的可行性体现在直接从相应的单体一锅制备出了几种四聚体。
Mechanistic studies of photohydration of <i>m</i>-hydroxy-1,1-diaryl alkenes
作者:John G Cole、Peter Wan
DOI:10.1139/v01-196
日期:2002.1.1
reported for the parent m-hydroxy-α-phenylstyrene (5), which has been proposed as consisting of a water trimer-mediated excited state (formal) intramolecularprotontransfer (ESIPT) from the phenolic proton to the β-carbon of the alkene moiety to give an observable (by laser flash photolysis (LFP)) m-quinonemethide intermediate 6. For this purpose, derivatives of 5 with substituents (methyl or methoxy) on