6536-02-3

Upstream product

• 122-00-9 para-methylacetophenone 
• 540-49-8 cis+trans-dibromoethylene 
• 149104-90-5 4-acetylphenylboronic acid 
• 99-90-1 para-bromoacetophenone 
• 1112-55-6 tetravinylsilane 
• 13329-40-3 4-Iodoacetophenone 
• 103-30-0 (E)-1,2-diphenyl-ethene 
• 75-36-5 acetyl chloride 
• 28540-81-0 (E) 2-iodo-1-chloroethylene 
• 590-27-2 (E)-1,2-diiodoethene 
• 99-91-2 para-chloroacetophenone 
• 78-08-0 Triethoxyvinylsilane 
• 13440-24-9 anti-1,2-dibromo-1,2-diphenylethane 
• 4076-57-7 1-(dibromomethyl)-4-methylbenzene 

Downstream Products

• 95363-41-0 4,4'-dicinnamoylstilbene 
• 98802-81-4 4.4'-Bis-glyoxyloyl-stilben 
• 46922-11-6 4,4'-Diaethinyl-stilben 

Relevant academic research and scientific papers

The synthesis, photophysical characterization, and X-ray structure analysis of two polymorphs of 4,4′-diacetylstilbene

A palladium(II) acetate-catalyzed synthesis of 1 that utilizes the novel triazene 1-{4-[(E)-morpholin-4-yldiazenyl]phenyl}ethanone as a synthon is described. The room temperature absorption spectra of 1 in various solvents exhibited a π→π* transition in the range of 330-350 nm. Compound 1 was observed to be luminescent, with room-temperature solution and solid-state emission spectra that exhibited maxima in the range 400-500 nm. All room-temperature absorption and emission spectra exhibited some degree of vibrational structure. The emission spectrum of 1 at 77 K in propanenitrile glass was broad and featureless with a maximum at 447 nm. Compound 1 crystallized as a yellow and colorless polymorph. X-Ray structure analyses of both of these polymorphs and 1-{4-[(E)-morpholin-4-yldiazenyl]phenyl}ethanone are presented.

An effective Pd nanocatalyst in aqueous media: Stilbene synthesis by Mizoroki-Heck coupling reaction under microwave irradiation

Aqueous Mizoroki-Heck coupling reactions under microwave irradiation (MW) were carried out with a colloidal Pd nanocatalyst stabilized with poly(N-vinylpyrrolidone) (PVP). Many stilbenes and novel heterostilbenes were achieved in good to excellent yields starting from aryl bromides and different olefins. The reaction was carried out in a short reaction time and with low catalyst loading, leading to high turnover frequency (TOFs of the order of 100 h-1). The advantages like operational simplicity, high robustness, efficiency and turnover frequency, the utilization of aqueous media and simple product work-up make this protocol a great option for stilbene syntheses by Mizoroki-Heck reaction.

Method for preparing trans-diphenylethylene compound

The invention relates to a preparation method of organic compounds and provides a method for preparing a trans-diphenylethylene compound. The method comprises adding a gem-dibromomethyl aromatic hydrocarbon compound, copper and polyamine into a reactor in the presence of a solvent, carrying out deoxidizing treatment, adding an oxygen-free water-free solvent into the reactor, carrying out a coupling reaction process to obtain C-C- double bonds, and carrying out separation and purification to obtain the trans-diphenylethylene compound. The method has mild synthesis conditions and has good reaction compatibility to different functional groups. The gem-dibromomethyl aromatic hydrocarbon compound as a raw material is easy to synthesize, may have different substituent groups and has a variable structure. The product obtained by coupling a raw material can be simply treated and has high purity. The asymmetric trans-diphenylethylene compound can be prepared from two different raw materials.

E-Stilbene derivatives synthesized by stereoselective reductive coupling of benzylic gem-dibromide promoted by Cu/polyamine

Stereoselective reductive coupling reaction of benzylic gem-dibromide promoted by Cu/polyamine produces E-stilbene derivatives with high yield under mild conditions. It provides a short pathway to synthesize symmetrical and asymmetrical E-stilbene derivatives using cheap reagents and alkenyl-free starting material together with easy workup.

Mechanistic studies on the Pd-catalyzed vinylation of aryl halides with vinylalkoxysilanes in water: The effect of the solvent and NaOH promoter

The mechanism of the Pd-catalyzed vinylation of aryl halides with vinylalkoxysilanes in water has been studied using different catalytic precursors. The NaOH promoter converts the initial vinylalkoxysilane into a highly reactive water-soluble vinylsilanolate species. Similarly, deuterium-labeling experiments have shown that, irrespective of the catalytic precursor used, vinylation occurs exclusively at the CH vinylic functionality via a Heck reaction and not at the C-Si bond via a Hiyama cross-coupling. The involvement of a Heck mechanism is interpreted in terms of the reduced nucleophilicity of the base in water, which disfavors the transmetalation step. The Heck product (β-silylvinylarene) undergoes partial desilylation, with formation of a vinylarene, by three different routes: (a) hydrolytic desilylation by the aqueous solvent (only at high temperature); (b) transmetalation of the silyl olefin on the PdH Heck intermediate followed by reductive elimination of vinylarene; (c) reinsertion of the silyl olefin into the PdH bond of the Heck intermediate followed by β-Si syn-elimination. Both the Hiyama and Heck catalytic cycles and desilylation mechanisms b and c have been computationally evaluated for the [Pd(en)Cl2] precursor in water as solvent. The calculated Gibbs energy barriers support the reinsertion route proposed on the basis of the experimental results.

Supported palladium nanoparticles as heterogeneous ligand-free catalysts for the Hiyama C-C coupling of vinylsilanes and halobenzenes leading to styrenes

The Hiyama C-C coupling reaction of a wide range of aryl iodides and vinylsilanes has been performed using ligand-free solid catalysts based on supported palladium nanoparticles. Among the supports tested (Mg, TiO 2, CeO2 and active carbon), the most active catalysts were those in which palladium is supported on MgO and TiO2. Analogous Pt and Au materials were inefficient to promote this reaction. Leaching tests suggest that there is some contribution of dissolved Pd since Pd in solution has been detected and the scavenging test decreases the initial reaction rate. Although the solid Pd catalysts can be reused, it was, however, observed that they undergo a certain deactivation upon use that can be attributed to several factors including the presence of inorganic compounds on the catalyst, Pd leaching or agglomeration of Pd NPs.

Palladium-catalyzed cross-coupling reactions of potassium alkenyltrifluoroborates with organic halides in aqueous media

Potassium vinyl and alkenyltrifluoroborates are cross-coupled with aryl and heteroaryl bromides using 1 mol % Pd loading of 4-hydroxyacetophenone oxime derived palladacycle or Pd(OAc)2 as precatalysts, K 2CO3 as base, and TBAB as additive and water reflux under conventional or microwave heating to afford styrenes, stilbenoids, and alkenylbenzenes. These borates can be cross-coupled diastereoselectively with allyl and benzyl chlorides using KOH as base in acetone-water (3:2) at 50°C and 0.1 mol % Pd loading, giving the corresponding 1,4-dienes and allylarenes, respectively. These simple phosphine-free reaction conditions allow the palladium recycling from the aqueous phase during up to five runs by extractive separation of the products, which contain 58-105 ppm of Pd.

Consecutive palladium-catalyzed Hiyama-Heck reactions in aqueous media under ligand-free conditions

Symmetric and asymmetric (E)-1,2-diarylethenes are synthesized from aryl bromides by consecutive one-pot Hiyama-Heck reactions carried out in water and under air; the only additives required are sodium hydroxide, palladium acetate and poly(ethylene glycol), and the products are isolable in many cases by simple filtration of the water solution. The Royal Society of Chemistry.

Suzuki-Miyaura cross-coupling reactions of potassium vinyltrifluoroborate with aryl and heteroaryl electrophiles

We have previously reported that the palladium-catalyzed cross-coupling reaction of potassium vinyltrifluoroborate with aryl electrophiles proceeds with good yields. Herein, we describe recent progress in optimizing the reaction, as well as outlining the scope and limitations of the reaction. The cross-coupling reaction can generally be effected using 2 mol % of PdCl2 and 6 mol % of PPh3 as a catalyst system in THF/H2O with Cs 2CO3 as a base. Moderate to good yields are obtained in the presence of a variety of functional groups.

The effect of vicinyl olefinic halogens on cross-coupling reactions using Pd(0) catalysis

(trans) 1-Chloro-2-iodoethylene (3), (trans) 1-bromo-2-iodoethylene (4), (trans) 1,2-diiodoethylene (5) and (cis and trans) 1,2-dibromoethylene (11) were reacted under Suzuki, Sonogashira and Negishi cross-coupling conditions using Pd catalysis to obtain mono coupled products. Only olefin template 3 provided the desired coupling products reliably under all reaction conditions. Compound 5 did not provide cross coupled products under any of the reaction conditions used. The Negishi reaction was the only one that worked for templates 4 and 11. Studies indicate that oxidative addition of the most reactive carbon-halogen bond to Pd(0) is followed by elimination of the second halide, when the second halide is a bromide or an iodide. This happens to a much lesser degree when the second halogen is a chloride. Graphical Abstract.