95061-64-6Relevant academic research and scientific papers
Controlling reactivity in the Fujiwara–Moritani reaction: Examining solvent effects and the addition of 1,3-dicarbonyl ligands on the oxidative coupling of electron rich arenes and acrylates
Jones, Roderick C.
supporting information, (2019/12/25)
A palladium-catalysed direct alkenation of electron rich arenes in the presence of K2S2O8 with an acetic acid/1,4-dioxane solvent combination has been developed. The 1,4-dioxane co-solvent dramatically influences the rate of reaction, giving selectively disubstituted alkenes, while the addition of acetylacetone ligands was shown to increase site selectivity for the alkenation of monofunctionalized arenes. The participation of these carbonyl ligands has been confirmed by ESI-MS studies, with some key in situ intermediates in the catalytic cycle identified. A variety of electron rich arenes and olefinic substrates can be utilised in the direct oxidative coupling to give disubstituted alkenes in moderate to good yields.
S,O-Functionalized Metal-Organic Frameworks as Heterogeneous Single-Site Catalysts for the Oxidative Alkenylation of Arenes via C-H activation
Bals, Sara,Bugaev, Aram L.,Dallenes, Jesse,De Vos, Dirk E.,Henrion, Micka?l,Krajnc, Andra?,Liu, Pei,Mali, Gregor,Soldatov, Alexander V.,Van Velthoven, Niels
, p. 5077 - 5085 (2020/05/27)
Heterogeneous single-site catalysts can combine the precise active site design of organometallic complexes with the efficient recovery of solid catalysts. Based on recent progress on homogeneous thioether ligands for Pd-catalyzed C-H activation reactions, we here develop a scalable metal-organic framework-based heterogeneous single-site catalyst containing S,O-moieties that increase the catalytic activity of Pd(II) for the oxidative alkenylation of arenes. The structure of the Pd?MOF-808-L1 catalyst was characterized in detail via solid-state nuclear magnetic resonance spectroscopy, N2 physisorption, and high-angle annular dark field scanning transmission electron microscopy, and the structure of the isolated palladium active sites could be identified by X-ray absorption spectroscopy. A turnover frequency (TOF) of 8.4 h-1 was reached after 1 h of reaction time, which was 3 times higher than the TOF of standard Pd(OAc)2, ranking Pd?MOF-808-L1 among the most active heterogeneous catalysts ever reported for the nondirected oxidative alkenylation of arenes. Finally, we showed that the single-site catalyst promotes the oxidative alkenylation of a broad range of electron-rich arenes, and the applicability of this heterogeneous system was demonstrated by the gram-scale synthesis of industrially relevant products.
Ionic Pd/NHC Catalytic System Enables Recoverable Homogeneous Catalysis: Mechanistic Study and Application in the Mizoroki–Heck Reaction
Eremin, Dmitry B.,Denisova, Ekaterina A.,Yu. Kostyukovich, Alexander,Martens, Jonathan,Berden, Giel,Oomens, Jos,Khrustalev, Victor N.,Chernyshev, Victor M.,Ananikov, Valentine P.
supporting information, (2019/11/14)
N-Heterocyclic carbene (NHC) ligands are ubiquitously utilized in catalysis. A common catalyst design model assumes strong M–NHC binding in this metal–ligand framework. In contrast to this common assumption, we demonstrate here that lability and controlled cleavage of the M?NHC bond (rather than its stabilization) could be more important for high-performance catalysis at low catalyst concentrations. The present study reveals a dynamic stabilization mechanism with labile metal–NHC binding and [PdX3]?[NHC-R]+ ion pair formation. Access to reactive anionic palladium intermediates formed by dissociation of the NHC ligands and plausible stabilization of the molecular catalyst in solution by interaction with the [NHC-R]+ azolium ion is of particular importance for an efficient and recyclable catalyst. These ionic Pd/NHC complexes allowed for the first time the recycling of the complex in a well-defined form with isolation at each cycle. Computational investigation of the reaction mechanism confirms a facile formation of NHC-free anionic Pd in polar media through either Ph–NHC coupling or reversible H–NHC coupling. The present study formulates novel ideas for M/NHC catalyst design.
Tandem allylic oxidation-condensation/esterification catalyzed by silica gel: An expeditious approach towards antimalarial diaryldienones and enones from natural methoxylated phenylpropenes
Sharma, Abhishek,Sharma, Naina,Shard, Amit,Kumar, Rakesh,Mohanakrishnan, Dinesh,Saima,Sinha, Arun K.,Sahal, Dinkar
, p. 5211 - 5219 (2011/08/07)
A new one-pot strategy has been developed, wherein abundantly available methoxylated phenylpropenes are directly transformed into corresponding dienones (1,5-diarylpenta-2,4-dien-1-ones) and enones (chalcones and cinnamic esters) via allylic oxidation-condensation or allylic oxidation-esterification sequences. Preliminary antimalarial activity studies of the above synthesized diaryldienones and enones against Plasmodium falciparum (Pf3D7) have shown them to be promising lead candidates for developing newer and economical antimalarial agents. In particular, two enones (12b and 13b) were found to possess comparatively better activity (IC50 = 4.0 and 3.4 μM, respectively) than licochalcone (IC50 = 4.1 μM), a well known natural antimalarial compound. The Royal Society of Chemistry 2011.
PALLADIUM(0) AND RHODIUM(I) CATALYSIS OF THE CARBONYLATION OF UNACTIVATED BROMIDES
Hashem, Khaled E.,Woell, James B.,Alper, Howard
, p. 4879 - 4880 (2007/10/02)
Alkyl, vinyl, and aromatic bromides react with organoborates and carbon monoxide, in the presence of catalytic quantities of 1,5-hexadienerhodium(I) chloride dimer and tetrakis(triphenylphosphine)palladium(0), to give carboxylic esters in good yields.
