115665-94-6Relevant academic research and scientific papers
Synthesis of (E)-1-aryl alk-1-en-3-ones by tetraphosphine/palladium- catalysed Heck reactions of alk-1-en-3-ones with aryl bromides
Lemhadri, Mhamed,Doucet, Henri,Santelli, Maurice
, p. 2935 - 2940 (2006)
The tetraphosphine cis,cis,rediscovercis-1,2,3,4- tetrakis(diphenylphosphinomethyl)cyclopentane in combination with [Pd(C 3H5)Cl]2 affords a very efficient catalyst for the Heck reaction of alk-1-en-3-ones with aryl bromides. If appropriate reaction conditions are used (NaOAc as base, hydroquinone as stabilising agent and DMF as solvent) high yields of (E)-1-aryl alk-1-en-3-one derivatives are obtained. In general, higher reaction rates were observed with electron-poor aryl bromides, but the electron-rich aryl bromides 4-N,N-dimethylaminobromobenzene and 4-bromoanisole also led to the arylated enones. Even with sterically very congested aryl bromides such as 9-bromoanthracene, 2,4,6-trimethylbromobenzene or 2,4,6-triisopropylbromobenzene, the expected (E)-1-aryl alk-1-en-3-ones were obtained in moderate to good yields. Moreover, several reactions can be performed with as little as 0.1% catalyst. Georg Thieme Verlag Stuttgart.
Preparation of monometallic (Pd, Ag) and bimetallic (Pd/Ag, Pd/Ni, Pd/Cu) nanoparticles via reversed micelles and their use in the Heck reaction
Heshmatpour, Felora,Abazari, Reza,Balalaie, Saeed
experimental part, p. 3001 - 3011 (2012/05/31)
The metal nanoparticles (NPs) have been prepared using a water-in-oil microemulsion system of water/dioctyl sulfosuccinate sodium salt (aerosol-OT, AOT)/isooctane at 25 °C. Since the NPs produced in this system can endure forcing conditions (100 °C), this system has been used for the synthesis of nano-catalysts in the Heck reactions. FE-SEM, DLS, and UV/vis analyses have been used to characterize the surface morphology, size, and proof of the formation of all the prepared metal NPs, respectively. In addition, the effects of some reaction parameters (here, bases and solvents) were optimized. Differences in the catalytic properties of the synthesized NPs have also been investigated. Consequently, the Pd/Cu (4:1) bimetallic NP showed the highest activity in the C-C coupling reaction of the iodobenzene with the styrene, thus it is employed as the superior catalyst in this study. Therefore, the Pd/Cu (4:1) bimetallic NPs were further investigated using TEM and XRD analyses. This catalyst system is also reusable for six runs with very negligible reduction in the efficiency.
A selective and benign synthesis of functionalized benzalacetones via Mizoroki-Heck reaction using aryldiazonium salts
Stern, Therese,Rueckbrod, Sven,Czekelius, Constantin,Donner, Constanze,Brunner, Heiko
experimental part, p. 1983 - 1992 (2010/11/04)
Palladium-catalyzed Mizoroki-Heck reactions were carried out in the presence of calcium carbonate in alcoholic solvents. Under these conditions an efficient preparation of functionalized benzalacetones was developed. The reactions were carried out at room temperature and aerobic conditions, giving the products within several minutes in up to 95% isolated yields. Furthermore, some kinetic investigations, mechanistic insights and considerations are presented.
Regioselective heck vinylation of electron-rich olefins with vinyl halides: Is the neutral pathway in operation?
McConville, Matthew,Saidi, Ourida,Blacker, John,Xiao, Jianliang
experimental part, p. 2692 - 2698 (2009/08/15)
Highly regioselective vinylation of electron-rich olefins by bromo- as well as chlorostyrenes is effected by palladium catalysis with either mono- or bidentate phosphines in a molecular solvent, with no need for halide scavengers, ionic liquids, or ionic additives. The use of the hemilabile 1,3-bis(diphenylphosphino)propane monoxide (dpppO) as a ligand led to faster reactions of more challenging 2-substituted vinyl ethers and reduced Pd loadings. In contrast to the related arylation reaction, evidence suggests that the vinylation may proceed via the neutral Heck mechanism.
Palladium-catalysed heck reactions of alk-1-en-3-ones with aryl bromides: A very simple access to (E)-1-arylalk-1-en-3-ones
Lemhadri, Mhamed,Fall, Yacoub,Doucet, Henri,Santelli, Maurice
experimental part, p. 1021 - 1035 (2009/12/02)
When appropriate reaction conditions are used, very high yields of (E)-1-arylalk-1-en-3-one derivatives can be obtained by palladium-catalysed reactions of alk-1-en-3-ones with aryl bromides. The tetraphosphine cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl) cyclopentane in combination with [Pd(C3H5)Cl]2 was found to be a very efficient catalyst for this reaction. In general, higher reaction rates were observed with electron-poor aryl bromides, but the electron-rich aryl bromides 1-bromo-4-(dimethylamino)benzene and 4-bromoanisole also led to the arylated enones in high yields. Even with sterically very congested aryl bromides such as 9-bromoanthracene, 1-bromo-2,4,6-trimethylbenzene or 1-bromo-2,4,6-triisopropylbenzene, the expected (E)-1-arylalk-1-en-3-ones were obtained in moderate to good yields. These enones appear to be unstable under the reaction conditions, and the addition of a small amount of hydroquinone to the reaction mixture was found to be crucial, especially for the vinylation of electron-deficient aryl bromides. A variety of alk-1-en-3-ones has been employed, and better results in terms of substrate/ catalyst ratios were obtained when oct-1-en-3-one or hex-1-en-3-one was used than when but-1-en-3-one or pent-1-en-3-one was used. It should be noted that several reactions can be performed with as little as 0.1-0.001 mol% catalyst. Georg Thieme Verlag Stuttgart.
Heck-type coupling vs. conjugate addition in phosphine-rhodium catalyzed reactions of aryl boronic acids with α,β-unsaturated carbonyl compounds: A systematic investigation
Zou, Gang,Guo, Jianping,Wang, Zhiyong,Huang, Wen,Tang, Jie
, p. 3055 - 3064 (2008/02/09)
The competition between Heck-type coupling and conjugate addition in phosphine-rhodium catalyzed reactions of aryl boronic acids with α,β-unsaturated carbonyls has been systematically investigated in a toluene-H2O biphasic system. Aside from the intrinsic nature of rhodium and the enolization of carbonyls, the phosphine supporting ligand on rhodium, the ratio of aryl boronic acid to α,β-unsaturated carbonyl and the pH value of the aqueous phase were found to affect the competition significantly. Highly selective rhodium-based catalyst systems have therefore been developed for both Heck-type coupling and conjugate addition by synergistically tuning the supporting ligand, the boronic acid to olefin ratio and other reaction conditions. Conjugate addition with selectivity >99% and Heck-type coupling with selectivity of up to 100%, 98% and 84% for acrylates, acrylamides and methyl vinyl ketone, respectively, could be achieved in the rhodium-catalyzed reactions of aryl boronic acids with α,β- unsaturated carbonyls using the corresponding optimized rhodium-based catalyst systems. The Royal Society of Chemistry.
Carbon-carbon bond forming reactions in supercritical carbon dioxide in the presence of a supported palladium catalyst
Cacchi, Sandro,Fabrizi, Giancarlo,Gasparrini, Francesco,Villani, Claudio
, p. 345 - 347 (2007/10/03)
The reaction of aryl iodides or vinyl triflates with a variety of olefins in supercritical carbon dioxide (scCO2), in the presence of triethylamine and palladium on carbon, has been investigated. Methyl acrylate, styrene and acrylonitrile afford vinylic substitution products. Butenone reacts with aryl iodides to form a mixture of vinylic substitution and hydroarylation (formal conjugate addition) products. n-Butyl, vinyl ether gives rise to the formation of products arising from the α- and β- arylation process.
