Heterogeneous Catalyst Based On Click Reaction: Design, Synthesis And Catalytic Activity

Aimed to overcome problems exsited in the field of heterogeneouscatalysis, a highly efficient and novel protocol has been developed for theconstruction of immobilized catalysts in this paper, whose catalyticactivity and recyclability have also been evaluated in organic catalysis.Via the [3+2] azide-alkyne “Click” reaction, an oxime palladacyclehas been supported onto silica gel. The structure and composition of thesolid catalyst were further characterized by FT-IR, UV-Vis, ICP-MS, EA.The obtained palladium catalyst has shown promising activity for aerobicoxidation of benzyl alcohols, with the isolated yield up to99%.Meanwhile, the solid catalyst could be easily separated from the reactionmixture and its catalytic activity did not deteriorate even after it wasrecycled four times. Moreover, the application of the catalyst could besucessfully expand to the Suzuki coupling reactions, given the desiredproducts in moderate to excellent yields, and the turn over number of thecatalyst in the reaction was up to9900. Via a dual functional click-triazole, a new mesoporous SBA-15supported catalyst PdLn@SBA-15have been prepared, of which theclick-triazole acts as a stable linker as well as a good chelator toparticipate in the catalytic reactions. The architecture and coordinationstate of the novel catalyst have been sufficiently characterized with XRD,TEM, nitrogen sorption measurements and UV-Vis,~1H NMR, COSYrespectively. The catalyst was further applied for the aerobic oxidation ofalcohols with promising yields and selectivities, which could be reusedfor8cycles with a consistent catalytic activity, giving the products inexcellent yields.