- Ruthenium-Catalyzed E-Selective Alkyne Semihydrogenation with Alcohols as Hydrogen Donors
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Selective direct ruthenium-catalyzed semihydrogenation of diaryl alkynes to the corresponding E-alkenes has been achieved using alcohols as the hydrogen source. The method employs a simple ruthenium catalyst, does not require external ligands, and affords the desired products in > 99% NMR yield in most cases (up to 93% isolated yield). Best results were obtained using benzyl alcohol as the hydrogen donor, although biorenewable alcohols such as furfuryl alcohol could also be applied. In addition, tandem semihydrogenation-alkylation reactions were demonstrated, with potential applications in the synthesis of resveratrol derivatives.
- Ekebergh, Andreas,Begon, Romain,Kann, Nina
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p. 2966 - 2975
(2020/03/04)
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- Pd nanoparticles immobilized on Fe3O4 @ poly(ethylene glycol) bridged amine functionalized imidazolium ionic liquid: A magnetically separable catalyst for heck in water
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A palladium-based catalyst supported on novel Fe3O4 @ Poly(ethylene glycol) bridged amine functionalized imidazolium ionic liquid (Fe3O4@PEG-AIm-NH2- IL) was successfully prepared by a facile method. The catalyst was characterized by FT-IR, TEM, VSM, XRD, XPS and TGA-DSC, which showed high activity and stability for the Heck reaction in pure water. Furthermore, the catalyst could be recovered in a facile manner from the reaction mixture and recycled five times without any loss in activity.
- Liu, Xiang,Zhao, Xiaohua,Lu, Ming
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p. 1549 - 1556
(2019/11/28)
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- Evidences of release and catch mechanism in the Heck reaction catalyzed by palladium immobilized on highly cross-linked-supported imidazolium salts
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Palladium (10 wt%) on a highly cross-linked imidazolium-based material was used as catalyst in 0.1 mol% in the Heck reaction between several alkenes and aryl iodides. Products were obtained from good to high yields. Deeper investigations showed a release of Pd species in solution and their capture by the imidazolium-based support. When a sixfold amount of support was employed the re-captured Pd species (0.5-0.6 wt%) were not anymore catalytically active. This result represents a new interesting aspect of this work since the highly cross-linked imidazolium-based material can act also as Pd scavenger avoiding the release of the metal in solution. Important differences between Heck and Suzuki reactions have been evidenced when the reactions were carried out in the presence of the scavenging support.
- Pavia, Cinzia,Giacalone, Francesco,Bivona, Lucia Anna,Salvo, Anna Maria Pia,Petrucci, Chiara,Strappaveccia, Giacomo,Vaccaro, Luigi,Aprile, Carmela,Gruttadauria, Michelangelo
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- Design, synthesis and structure-activity relationships of some novel, highly potent anti-invasive (E)- and (Z)-stilbenes
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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.
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p. 5054 - 5063
(2013/09/02)
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- Scope and limitations of the Heck-Matsuda-coupling of phenol diazonium salts and styrenes: A protecting-group economic synthesis of phenolic stilbenes
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4-Phenol diazonium salts undergo Pd-catalyzed Heck reactions with various styrenes to 4′-hydroxy stilbenes. In almost all cases higher yields and fewer side products were observed, compared to the analogous 4-methoxy benzene diazonium salts. In contrast, the reaction fails completely with 2- and 3-phenol diazonium salts. For these substitution patterns the methoxy-substituted derivatives are superior. The Royal Society of Chemistry 2013.
- Schmidt, Bernd,Elizarov, Nelli,Berger, René,H?lter, Frank
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p. 3674 - 3691
(2013/06/27)
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