- Palladium-catalyzed decarboxylative coupling of α,β-unsaturated carboxylic acids with aryl tosylates
-
We report a general method for selective cross-coupling of α,β-unsaturated carboxylic acids with aryl tosylates enabled by versatile Pd(II) complexes. This method features the general cross-coupling of ubiquitous α,β-unsaturated carboxylic acids by decarboxylation. The transformation is characterized by its operational simplicity, the use of inexpensive, air-stable Pd(II) catalysts, scalability and wide substrate scope. The reaction proceeds with high trans selectivity to furnish valuable (E)-1,2-diarylethenes.
- Zhang, Wei,Chen, Gairong,Wang, Kaikai,Xia, Ran
-
-
- Preparation method of palladium catalyzed 1,2-trans diaryl alkene
-
The invention discloses a preparation method of palladium catalyzed 1,2-trans diaryl alkene. The method comprises the following steps that under the effects of catalysts, cocatalysts and alkali, arylacrylic acid and aromatic esters p-toluene sulfonate take decarboxylation coupling reaction in an organic solvent; after the reaction is finished, the 1,2-trans diaryl alkene is obtained through posttreatment. The method has the advantages that through C-O bond fracture, the operation is simple; a stable palladium catalyst with low cost is used; the substrate applicability is high; the harsh reaction conditions and the addition of strong alkali are not needed; the trans 1,2-diaryl alkene can be generated at high selectivity.
- -
-
Paragraph 0046-0048
(2019/06/11)
-
- Diarylethene synthesis method without transition metal catalysis
-
The invention discloses a diarylethene synthesis method without transition metal catalysis. The method comprises the following steps: a cinnamic acid derivative and aryl trifluoroborate are subjectedto a decarboxylation coupling reaction in a solvent under the action of an oxidizing agent, postprocessing is performed after the reaction, and diarylethene is obtained. K2S2O8 is adopted to promote acatalytic system in the synthetic method, and a free radical coupling reaction can be performed directly under the condition that no ligand, transition metal or alkali is added. The method has widersubstrate range and higher yield; the method is simple to operate, reaction conditions are mild, and large-scale application is facilitated.
- -
-
Paragraph 0046-0050
(2019/02/06)
-
- Synthesis, structure and catalytic activity of xylylene-bridged dipalladium complexes with triazolylidene ligands
-
A series of di-N-heterocyclic carbene (NHC) dipalladium complexes, [PdPyBr2]2(di-NHC) (2a–h), in which di-NHC represents a di-triazolylidene, featuring a 1,4-xylylene spacer between the carbene units, have been prepared from the reactions of the corresponding ditriazolium bromides with PdCl2 and excess NaBr as an additive in the presence of K2CO3 in pyridine. All of the complexes were fully characterized by NMR spectra, IR and elemental analyses. The molecular structure of 2b was determined by X-ray diffraction study, showing the intermolecular hydrogen bonding of Br···H–C. The influences of size of ligands on the catalytic activity have been investigated in the Heck reaction of styrene with bromobenzene. The complex 2g showed the best catalytic activity, and it is active for various aryl bromides with different electronic and steric properties and styrenes with both electron-donating and electron-withdrawing groups.
- Du, Yufeng,Liang, Beibei,Yang, Fenglei,Shi, Yanhui,Li, Xiuling,Pang, Guangsheng,Cao, Changsheng
-
p. 193 - 201
(2017/03/16)
-
- Synthesis of stilbene derivatives via visible-light-induced cross-coupling of aryl diazonium salts with nitroalkenes using-NO2 as a leaving group
-
The straightforward visible-light-induced synthesis of stilbene compounds via the cross-coupling of nitroalkenes and diazonium tetrafluoroborates under transition-metal-free conditions is described. The protocol uses green LEDs as light sources and eosin Y as an organophotoredox catalyst. Broad substrate scope and exclusive selectivity for the (E)-configuration of stilbenes are observed. This protocol proceeds via a radical pathway, with nitroalkenes serving as the radical acceptor, and the nitro group is cleaved during the process.
- Zhang, Na,Quan, Zheng-Jun,Zhang, Zhang,Da, Yu-Xia,Wang, Xi-Cun
-
supporting information
p. 14234 - 14237
(2016/12/14)
-
- Hydrogen Peroxide Promoted Mizoroki-Heck Reactions of Phenyldiazenes with Acrylates, Acrylamides, and Styrenes
-
Mizoroki-Heck reactions, which are well-known for aryldiazonium salts and which have recently been described for arylhydrazines, have now been extended to phenyldiazenes. In situ generation of phenyldiazenes from azocarboxylates allowed clean and selective reactions with styrenes, acrylates, and acrylamides using palladium(II) acetate in the presence of silver(I) acetate or hydrogen peroxide as oxidant. Hydrogen peroxide was thereby shown to be a cheap and broadly applicable alternative for the established palladium-silver(I) system.
- Lasch, Roman,Fehler, Stefanie K.,Heinrich, Markus R.
-
supporting information
p. 1586 - 1589
(2016/05/02)
-
- Cross-coupling reactions catalyzed by an N-heterocyclic carbene-Pd(ii) complex under aerobic and CuI-free conditions
-
A Pd-complex, (Cat. 3), has been successfully employed as a highly efficient and recyclable catalyst for the Sonogashira and Heck reactions of aryl bromides with various terminal acetylenes and olefins. The catalytic reactions proceed with excellent yields with a low catalyst loading (1.0 mol%) under aerobic and CuI-free conditions. A plausible mechanism has also been proposed for the reaction. the Partner Organisations 2014.
- Lu, Hongfei,Wang, Lin,Yang, Feifei,Wu, Runze,Shen, Wei
-
p. 30447 - 30452
(2014/08/05)
-
- β-cyclodextrin-capped palladium nanoparticle-catalyzed ligand-free Suzuki and Heck couplings in low-melting β-cyclodextrin/NMU mixtures
-
Low-melting β-cyclodextrin/N-methylurea (NMU) mixture, an efficient catalytic system for ligand-free Suzuki and Heck couplings in the presence of fresh native β-CD-capped Pd0 nanoparticles, has been successfully reported. This natural and convenient system can be performed in air and could afford the corresponding cross-coupled products in good to excellent isolated yields after a simple workup under every low Pd loading (0.05 mol%). Remarkably, the catalytic system can be recycled and reused without loss of catalytic activity. Copyright
- Zhao, Xiaohua,Liu, Xiang,Lu, Ming
-
p. 635 - 640
(2014/08/05)
-
- Novel polymer supported iminopyridylphosphine palladium (∥) complexes: An efficient catalyst for Suzuki-Miyaura and Heck cross-coupling reactions
-
A novel cross-linked polyallylamine polymer supported iminopyridylphosphine palladium∥ complexes have been prepared and shown to be highly efficient catalysts for Suzuki-Miyaura and Heck cross-coupling reactions under low Pd loading (0.05% mol). Remarkably, the catalyst can be recycled and reused without loss of catalytic activity through simple filtration.
- Liu, Xiang,Zhao, Xiaohua,Lu, Ming
-
-
- Expeditious synthesis of fluorinated styrylbenzenes and polyaromatic hydrocarbons
-
A series of fluorinated styrylbenzene derivatives were synthesized by the Mizoroki-Heck reaction using phosphine-free catalytic conditions or by adopting the one-pot Wittig-Heck reaction sequence. The fluorinated styrylbenzenes were converted into polyaromatic hydrocarbons such as phenanthrenes, [4]helicenes, and benzo[ghi]perylene by a modified photocyclization procedure involving I 2-THF condition.
- Bedekar, Ashutosh V.,Chaudhary, Anju R.,Shyam Sundar,Rajappa, Murali
-
p. 392 - 396
(2013/02/23)
-
- Design, synthesis and structure-activity relationships of some novel, highly potent anti-invasive (E)- and (Z)-stilbenes
-
In our ongoing exploration of the structure-activity landscape of anti-invasive chalcones, we have prepared and evaluated a number of structurally related (E)- and (Z)-stilbenes. These molecules exhibited an extraordinary high in vitro potency in the chick heart invasion assay, being active up to 10 nmol L-1, a concentration level a 100-fold lower than the lowest effective doses that have been reported for natural analogues. Furthermore, they possess an interesting pharmacological profile in silico.
- Roman, Bart I.,De Coen, Laurens M.,Mortier, Séverine Thérèse F.C.,De Ryck, Tine,Vanhoecke, Barbara W.A.,Katritzky, Alan R.,Bracke, Marc E.,Stevens, Christian V.
-
p. 5054 - 5063
(2013/09/02)
-
- Cu(acac)2-catalyzed synthesis of functionalized bis(arylmethyl)zinc reagents and their olefination reaction with aromatic aldehydes
-
An efficient and facile copper(II) acetylacetonate catalyzed synthesis of functionalized bis(arylmethyl)zinc reagents from arylmethyl halides and their olefination reaction with aromatic aldehydes is reported. Aluminum trichloride was found to be the key ingredient in these reactions and (E)-stilbenes were obtained in high yields. Georg Thieme Verlag Stuttgart · New York.
- Fu, Ying,Hu, Xuemei,Chen, Yaojuan,Yang, Yanshou,Hou, Hongxia,Hu, Yulai
-
experimental part
p. 1030 - 1036
(2012/05/04)
-
- Effects of substituent and solvent on the UV absorption energy of 4,4′-disubstituted stilbenes
-
Twenty five samples of 4,4′-disubstituted stilbene derivatives were synthesized, and their UV absorption max wavelengths were determined in over 10 kinds of solvents including cyclohexane, ether, chloroform, acetonitrile and ethanol, in which 242 experimental data were recorded. The effects of substituents and solvents on the energy of their UV absorption max wavelengths were discussed. The research results showed: the energy of UV absorption max wavelengths of 4,4′-disubstituted stilbenes was mainly affected by their intramolecular structure (substituent effect) in a given solvent, that is, the energy is dominated by both of excited-state substituent parameter σ CC ex and polar substituent constant σ p. While their energy was dominated by the substituent effect and solvent effect in different kinds of solvents. An equation quantifying the energy of UV absorption max wavelengths of 4,4′-disubstituted stilbenes was developed. In addition, it is found that the n-octanol/water partition coefficient (logP) is more effective than the solvatochromic dye (E T(30)) in scaling the solvent effect. The equation employed the parameter logP has a better correlation and more specific physical meaning. Further, the energies of UV absorption max wavelengths of some reported compounds were predicted by the obtained equation, which are in agreement with their experimental values.
- Cao, Chenzhong,Chen, Guanfan,Wu, Yaxin
-
scheme or table
p. 1735 - 1744
(2012/05/05)
-
- Synthesis and biological evaluation of some stilbene-based analogues
-
The phytoalexin 3,5,40-trihydroxy-trans-stilbene (resveratrol) has attracted considerable attention from biologists and chemists due to its diverse biological properties. Owing to the biological importance of this compound, we have synthesized new stilbene-based analogues by using substituted benzyl chlorides and substituted aldehydes in a two-step reaction and evaluated their in vitro antioxidant, antibacterial and antifungal potential. Most of the compounds displayed moderate to significant radical scavenging activity. (E)-1-(3,4-difluorophenyl)-2-(4-fluorophenyl) ethene (4c) showed nearer equipotent antibacterial activity against Staphylococcus aureus. (E)-1,2-bis (4-fluorophenyl)ethene (4a), (E)-1-(3-fluorophenyl)-2-(4-fluorophenyl)ethene (4b), (E)-1-(2,4-dichlorophenyl)-2-(3, 4-dichlorophenyl)ethene (4f), (E)-1-(2,4-dichlorophenyl)-2-(3-chlorophenyl)ethene (4g), (E)-1-(2,4- dichlorophenyl)-2-(4-fluorophenyl)ethene (4j) (E)-1-(4-fluorophenyl)-2-(3- chlorophenyl)ethene (4l) and (E)-1-(4-chlorophenyl)-2-(4-fluorophenyl)ethene (4n) inhibited the growth of Penicillium chrysogenum. Springer Science+Business Media, LLC 2010.
- Karki, Subhas S.,Bhutle, Santosh R.,Pedgaonkar, Ganesh S.,Zubaidha,Shaikh, Rizwan M.,Rajput, Chitra G.,Shendarkar, Girish S.
-
p. 1158 - 1163
(2012/05/05)
-
- Palladium-catalyzed desulfitative heck-type reaction of aryl sulfinic acids with alkenes
-
An efficient protocol has been developed for the desulfitative Heck-type reaction of aryl sulfinic acids with a variety of alkenes in the presence of a catalytic amount of Pd(OAc)2 and inexpensive Cu(OAc)2 as oxidant. This method does not require a ligand or a base, thereby broadening the scope of Pd-catalyzed coupling reactions. Copyright
- Wang, Guan-Wu,Miao, Tao
-
p. 5787 - 5790
(2011/06/23)
-
- Arenediazonium salts immobilized in imidazolium ionic liquids as electrophilic partners in the Pd(OAc)2-catalyzed Matsuda-Heck arylation
-
The utility of arenediazonium salts immobilized in imidazolium-ILs [BMIMPF6 and BMIMBF4] for facile, high yielding, synthesis of olefins via the Pd(OAc)2-catalyzed Matsuda-Heck arylation reaction has been demonstrated. The reaction can also be performed as a two-step process in the IL starting from ArNH2, by sequential in-situ diazotization-arylation. Simple product isolation and the recycling/re-use of the IL are additional advantages of this one-pot method.
- Kalkhambkar, Rajesh G.,Laali, Kenneth K.
-
experimental part
p. 1733 - 1737
(2011/05/05)
-
- Substituent effect on the UV spectra of p-disubstituted compounds XPh(CH=CHPh)nY (n=0, 1, 2)
-
Three parameters, θCCex, θ CCex(XY) and Vmax,parent, are developed to express the substituent effect and the effect of the parent molecular structure of p-disubstituted compounds XPh(CH=CHPh)nY (n=0, 1, 2). The investigated result shows a good correlation between the UV absorption wavenumbers (Vmax) and the three parameters for a diverse set of title compounds, and the correlation equation can be used to predict the UV absorption energy of compounds with the mentioned structure. This approach provides a new insight for the quantitative structure-property relationship (QSPR) correlation of the UV absorption energy of p-disubstituted homologues. Copyright
- Chen, Guanfan,Cao, Chenzhong
-
scheme or table
p. 776 - 782
(2011/05/05)
-
- Thiadiazolidine 1-oxide systems for phosphine-free palladium-mediated catalysis
-
We herein report several highly active catalyst systems with thiadiazolidine 1-oxides as ligands for palladium in the Mizoroki-Heck reaction. Excellent yields of stilbenes derived from aryl iodides and bromides have been achieved using as little as 0.00002 mol % catalyst. The ligand/palladium system can be stored as a stock solution open to air at room temperature with no observable loss of activity for a period of several months.
- Buckley, Benjamin R.,Neary, Stephen P.
-
experimental part
p. 7988 - 7994
(2010/10/21)
-
- The first thiadiazolidine 1-oxide system for phosphine-free palladium-mediated catalysis
-
We herein report a highly active catalyst system using for the first time a thiadiazolidine 1-oxide as a ligand for palladium in the Mizoroki-Heck reaction. Excellent yields of stilbenes derived from aryl iodides and bromides have been achieved using as little as 0.00002 mol% catalyst. The ligand/ palladium system can be stored as a stock solution open to air at room temperature with no observable loss of activity for a period of several weeks/months.
- Buckley, Benjamin R.,Neary, Stephen P.
-
supporting information; scheme or table
p. 71 - 77
(2009/08/07)
-
- 1H NMR and UV-vis spectroscopy of fluorine and chlorine substituted stilbenes: Conformational studies
-
UV-vis and 1H NMR spectroscopic studies supported by molecular mechanics calculations reveal planar structure for the lowest energy conformations of a series of fluorine- and chlorine-substituted trans-stilbenes.
- Kvaran, á,ásgeirsson,Geirsson
-
p. 513 - 516
(2007/10/03)
-
- OLEFIN FORMATION VIA N,N,N',N'-TETRAMETHYLDIAMIDES OF 1,2-DIARYL-2-HYDROXYETHANEPHOSPHONIC ACIDS IN ACIDIC MEDIA
-
The olefin formation via the erythro-N,N,N',N'-tetramethyldiamides of 1,2-diaryl-2-hydroxyethanephosphonic acids 3,4 in the presence of aqueous hydrochloric acid proceeds not stereospecifically, while in ethanolic solution of hydrochloric acid (Z)-stereospecific olefin formation predominantly takes place.The mechanism of the elimination process is discussed.
- Petrova, Jordanka,Kirilov, Marko,Momchilova, Snejana,Kossev, Krassimir
-
-
- OLEFIN SYNTHESIS VIA THE LITHIUM DERIVATIVES OF THE N,N,N',N'-TETRAMETHYLDIAMIDES OF ARYLMETHANEPHOSPHONIC ACIDS. 2. SYNTHESIS OF SOME (Z)-ORTHO AND PARA SUBSTITUTED STILBENES
-
The reaction of the lithium derivatives of N,N,N',N'-tetramethyldiamides of arylmethanophosphonic acids (1-Li) with ortho- and para-substituted benzaldehydes 2 is studied.Reaction conditions are found for erythro-stereoselective addition of 1 to 2 with high diastereomeric purity (95-99percent) of the rythro adducts 3, 4 (yields 35-72percent).By thermolysis of the adducts in neutral medium the corresponding (Z)-ortho and para-substituted silbenes 5, 6 are obtained.Some factors causing the predominant formation of the erythro adducts 3, 4, as well as the influence of the ortho-substituents on the equilibrium are discussed.
- Petrova, Jordanka,Momchilova, Snejana,Kirilov, Marko
-
p. 243 - 250
(2007/10/02)
-