71617-10-2Relevant articles and documents
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.
A practical, efficient, and atom economic alternative to the Wittig and Horner-Wadsworth-Emmons reactions for the synthesis of (E)-α,β- unsaturated esters from aldehydes
List, Benjamin,Doehring, Arno,Hechavarria Fonseca, Maria T.,Job, Andreas,Rios Torres, Ramon
, p. 476 - 482 (2007/10/03)
We describe a highly efficient new methodology for the synthesis of (E)-α,β-unsaturated esters from aldehydes. In our DMAP-catalyzed reaction, both aromatic as well as aliphatic aldehydes furnish the desired products highly regio- and stereoselectively if treated with commercially available or synthetically easily accessible malonic acid half ester. A large scale application in the synthesis of p-methoxycinnamates, which are of use as sunscreen ingredients, is described.
Sulphonic acids and their use as UV absorbers
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, (2008/06/13)
PCT No. PCT/EP96/04325 Sec. 371 Date Apr. 16, 1998 Sec. 102(e) Date Apr. 16, 1998 PCT Filed Oct. 4, 1996 PCT Pub. No. WO97/14680 PCT Pub. Date Apr. 24, 1997Sulphonic acids of formula (I) in which the components and indices have the meanings given in the description, are eminently suitable as u/v absorbers, especially in cosmetic sun-screening agents.