42834-34-4

Upstream product

• 108-89-4 picoline 
• 1122-91-4 4-bromo-benzaldehyde 
• 589-15-1 1-bromomethyl-4-bromobenzene 
• 872-85-5 pyridine-4-carbaldehyde 
• 38186-51-5 diethyl (4-bromobenzyl)phosphonate 
• 589-17-3 p-bromobenzyl chloride 
• 100-43-6 4-vinylpyridine 
• 106-37-6 1.4-dibromobenzene 
• 5467-74-3 4-Bromophenylboronic acid 
• 589-87-7 1,4-bromoiodobenzene 
• 106-38-7 para-bromotoluene 
• 51044-13-4 4-bromobenzyl triphenylphosphonium bromide 

Downstream Products

• 25514-83-4 trans-4'-bromo-4-stilbazole methiodide 
• 1246993-71-4 rac-4,4'-((1R,2R,3S,4S)-2,4-bis(4-bromophenyl)cyclobutane-1,3-diyl)dipyridine 
• 138517-20-1 1-(4-bromophenyl)-2-(4-pyridyl)acetylene 

Relevant academic research and scientific papers

Palladium anchored on guanidine-terminated magnetic dendrimer (G3-Gu-Pd): An efficient nano-sized catalyst for phosphorous-free Mizoroki-Heck and copper-free Sonogashira couplings in water

In this research, a novel type of Fe3O4&at;silica-supported dendrimer capped by guanidine groups for immobilization of palladium was reported. This novel nano-sized catalyst was characterized by FTIR, TGA, XRD, FESEM, EDX, VSM, XPS and HRTEM methods. Enhanced catalytic activity of the prepared catalyst in Mizoroki-Heck and copper-free Sonogashira coupling reactions were evaluated in water as a green solvent. The influence of the various reaction parameters such as catalyst dosage, time and temperature on two mentioned C–C coupling reactions were studied. Results showed that the catalyst could be easily recovered by simple separation by an external magnet and reused for five cycles of recovery without considerable losing of its activity.

Polarizable stilbazole-based organometallic complexes and polymers

Oxidative addition reactions of trans-4'-bromo-4-stilbazole (1) to Pd(PMe3)4, Pd(PEt3)4, and Pd(PiPr3)3 yield the corresponding PdII complexes (5).The quaternary complexes (6 and 7) are obtained by methylation and protonation of 5.Bromide abstraction from 5 leads to the charged polymers 9.Comparison of the spectroscopic properties (UV, IR, NMR) of these complexes, as well as those of the gold complex 4, with those of the parent organic compounds indicates that there is considerable metal participation in the conjugated systems.The oscillator strength (f) for the ?-?* transition of the various compounds has been determined.The Pd and Au complexes have considerably higher f values than the parent bromostilbazoles, while palladium complexes exhibit a lower energy ?-?* transition than the latter.The nature of the phosphine ligand in the palladium complex has a minor effect on conjugation.

A new insight into the push-pull effect of substituents via the stilbene-like model compounds

In this paper, authors report on 1-pyridyl-2-arylethenes, 1-furyl-2-arylethylenes, 1,2-diphenylpropylenes and substituted cinnamyl anilines as stilbene-like model compounds to investigate the factors dominating the push-pull effect of substituents via usi

Determination and application of the excited-state substituent constants of pyridyl and substituted phenyl groups

Thirty six 1-pyridyl-2-arylethenes XCH=CHArY (abbreviated XAEY) were synthesized, in which, X is 2-pyridyl, 3-pyridyl and 4-pyridyl and Y is OMe, Me, H, Br, Cl, F, CF3, and CN. Their ultraviolet absorption spectra were measured in anhydrous ethanol, and their wavelengths of absorption maximum λmax were recorded. Also, the 234 λmax values of 1-substituted phenyl-2-arylethylene compounds (XAEY, where X is substituted phenyl) were collected. The excited-state substituent constants (Formula presented.) of three pyridyl groups and 23 substituted phenyl groups (total of 26) were obtained by means of curve-fitting method. Taking the λmax values of 358 samples of bi-arylethene derivatives as a data set and 126 samples of bi-aryl Schiff bases (including nine compounds synthesized by this work) as another data set, quantitative correlation analyses were performed by employing the obtained (Formula presented.) as a parameter, and good results were obtained for the two data sets. The reliability of the obtained (Formula presented.) values was verified. The results of this paper can provide excited-state substituent constants for the study and application of optical properties of conjugated organic compounds containing aryl groups.

[2+2] Photodimerization of Stilbazoles Promoted by Oxalic Acid in Suspension

In this study, a very simple technique to perform efficiently photodimerization of some vinylpyridines is reported. By irradiating a stirred mixture of several stilbazoles with solid oxalic acid dihydrate dispersed in a nonpolar (i.e., cyclohexane) or moderately polar (benzene, dichloromethane, dioxane) solvent, the corresponding dimeric cyclobutane adducts were obtained in high yields and excellent regio- and stereoselectivities. The strategy could also be applied successfully to oily, waxy, or even insoluble stilbazoles. Moreover, the oxalic acid loading could be lowered to substoichiometric amounts. When further optimizations were needed, our strategy was found to be highly flexible to identify other oligocarboxylic acids as alternative additives to improve, or even overturn, the regioselectivity. Oxalic acid and other oligocarboxylic acids were found to be capable of orienting more than 50 stilbazoles toward photodimerization under these conditions.

1-(4-pyridyl)-4-(4'-pyridyl vinyl) benzene and preparation method and application thereof

1-(4-pyridyl)-4-(4'-pyridyl vinyl) benzene is a compound which is prepared from 1-potential of a benzene ring, 4-potential of a pyridine group connected with 1-potential of the benzene ring, 4-potential of the benzene ring and vinyl of a 4-pyridyl vinyl group connected with 4-potential of the benzene ring. A preparation method includes the steps that first, 1-bromo-4-iodobenzene and 4-vinyl pyridine generate an intermediate which is 1-(4-pyridyl)-2-(4-bromophenyl) ethylene through a Heck reaction; then, the intermediate and 4-pyridine boric acid generate a target product which is 1-(4-pyridyl)-4-(4'-pyridyl vinyl) benzene through a Suzuki reaction. The preparation method is simple in technology, mild in reaction condition and high in yield. The 1-(4-pyridyl)-4-(4'-pyridyl vinyl) benzene compound serves as an electron donor to be applied to preparation of coordination compounds.

Ligand-free palladium-catalysed oxidative Heck reaction of 4-vinylpyridine with arylboronic acids: Selective synthesis of (E)-4-styrylpyridines

A ligand-free palladium-catalysed oxidative Heck reaction of various arylboronic acids with 4-vinylpyridine has been developed, achieving (E)-4-styrylpyridines with high selectively in moderate to good yields. A plausible mechanism for the formation of (E)-4-styrylpyridines has been proposed.

Chromophoric lewis base adducts of methyltrioxorhenium: Synthesis, catalysis and photochemistry

A series of chromophoric Lewis base adducts of methyltrioxorhenium (MTO) was examined. The ligands were pyridine derivatives with different size of the aromatic system and variable substituents, thus providing a variation of electronic and steric parameters. The complexes were fully characterised (UV/Vis, IR and NMR spectroscopy, single-crystal X-ray diffraction and elemental analysis) and their stability constants in dichloromethane were determined by means of UV/Vis spectroscopy. Moreover, this report presents a study of the influence of these N-donor ligands coordinated to MTO on the catalytic activity of epoxidation of 1-octene. Each compound was tested twice; in a catalytic reaction under exclusion of light and in daylight. No significant differences in catalytic performance were found. The behaviour of the complexes under irradiation with UV light viras investigated by means of 17O-NMR and UV/Vis spectroscopy. The herein exposed experiments aimed for probing potential beneficial effects of chromophoric N-donor ligands in MTO adducts, as they might activate the catalytic system by providing additional energy for weakening bonds that have to be broken during the catalytic cycle.

π-extended conjugate phenylacetylenes. Synthesis of 4-[(E) and (Z)-2-(4-ethenylphenyl)ethenyl]pyridine. Dimerization, quaternation and formation of charge-transfer complexes

The conjugate (E)- and (Z)-(4′-pyridylethenyl)-4-phenylethyne (E-4 and Z-4) has been satisfactorily prepared by two different routes: (a) by dehydrohalogenation of 4′-pyridylethenyl-4-phenyl-β-chloroethene; (b) by the Wittig reaction between p-(iodobenzyl)(triphenyl)phosphine ylide and 4-pyridinecarboxaldehyde, E/Z isomer separation, and cross-coupling with 2-methyl-but-3-yn-2-ol followed the propanone elimination. The Glaser oxidative dimerization of (Z)-4 yields (Z,Z)-1,4-di[(4′-pyridylethenyl)-4-phenyl]-buta-1,3-diyne in good yield, (Z,Z)-5. (E,E)-5 was obtained by phase transfer oxidative dimerisation of (E)-4 in presence of their N-methyl salt (E)-10. Mono- and di-N-methylated salts of conjugate (E,E)-5 and (Z,Z)-5, were obtained by quaternation with iodomethane. The (Z,Z)-5 di-N-methylated salt forms charge-transfer complexes with TCNE, TCNQ and TMPD.

Kinetics of Reaction of Phenacyl Bromide with 3- and 4-Substituted Pyridines and 4-Substituted 4-Styrylpyridines

The rates of reaction of phenacyl bromide with 3- and 4-substituted pyridines and 4'-substituted 4-styrylpyridines have been measured in aq. acetone (90percent, v/v) at 30 deg C, 35 deg C and 40 deg C and the activation parameters have been evaluated.Satisfactory Hammett correlations are obtained for both pyridine and styrylpyridine series.The effectiveness of transmission of substituent effect in styrylpyridine system relative to pyridine system in this reaction is calculated to be 0.104.From the Bronsted relationship the coefficient (βN) is found to be 0.48, indicating that the extent of bond formation in the transition state is moderate.