Katalyse in fluorigen Zweiphasensystemen ohne perfluorierte Lösungsmittel: Anwendung auf Pd-vermittelte Suzuki- und Sonogashira-Kupplungen

Palladium‐Based Catalytic Systems for the Synthesis of Conjugated Enynes by Sonogashira Reactions and Related Alkynylations

“…Fluorous reversed‐phase silica gel (FRPSG) have been used instead of the expensive and environmentally persistent fluorous solvents to immobilize fluorinated palladium–phosphane catalysts (Scheme 57, top) 138…”

“…The cross‐coupling of 4‐nitrobromobenzene and phenylacetylene was achieved in satisfactory yields of 98, 97, and 71 % for three successive experiments by using 2 mol % Pd/FRPSG catalysts in the presence of CuI/HN n Bu 2 in DME at 100 °C for 14 h; however, the catalytic activity and the recyclability dropped significantly in the third cycle and also if a lower amount of catalyst (0.2–0.002 mol %) was used 138. A study on a more diverse array of substrates would be necessary to determine the scope of these catalysts.…”

A Green and Highly Selective Oxidation of Alcohols by Fluorous Silica Gel‐Supported Gold Nanoparticles in Aqueous H2O2 under Base‐Free Conditions

“…Fluorous silica gel (FSG)‐supported catalyst is a new type of heterogeneous catalyst and has shown excellent catalytic efficiency and recyclability in a series of reactions 9. Such catalysts could also work well in aqueous medium despite the hydrophobicity of the support 9a,b,d,f,h,i. Recently, both Vallribera’s group and our group showed that metal nanoparticles could be stabilized by heavily fluorinated compounds (Figure 1) and immobilized on fluorous silica gel by fluorous–fluorous interactions, and the precatalyst could also be applied in a series of CC bond forming and oxidation reactions 9e–i.…”

Ring-closing olefin metathesis in the aqueous phase of amphiphilic conetworks consisting of fluorophilic and hydrophilic compartments

“…Its utility in RCM-reactions had been demonstrated by us after its noncovalent attachment to fluorous silica gel [13]. The advantage of this system is twofold: (a) noncovalent attachment allows for easy removal of the catalyst by filtration and (b) it obviates the need for perfluorinated solvents, which are expensive and environmentally persistent [14][15][16].…”