TY  - GEN
TI  - Catalytic properties of epoxy resins containing transition metal species
Y1  - 2007///
AV  - public
ID  - heidok7377
KW  - heterogeneous catalysis 
KW  -  epoxy resin 
KW  -  transition metal
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/7377/
A1  - Fan, Fengwen
N2  - In order to develop a simple and reliable protocol for the immobilization of catalytically active metal species, epoxy resins containing d-block metal species were prepared via polyaddition or homopolymerization of the resins using metal complexes as initiators and evaluated in the epoxidation of alkenes, C-C coupling reactions and hydrogenation of unsaturated substrates. The resins TGMDA, TGAP, Novolac, ERL4221, or TGAP/PT30 were cured in the presence of Mo(OEt)5, Mo(EH)n, H3Mo12O40P?xH2O, MoO2(TMHD)2, W(OEt)5, Ti(EH)4, VO(OPr)3 or V(NAPH)n and the catalytic activities of the resulting materials were evaluated in the epoxidation of liquid alkenes and propene with organic hydroperoxides as oxidants. This part represents investigations on different curing methods, the relation between catalytic activity and metal species leaching, and the nature of true active species. Insights into long-term activities and stabilities of the catalysts were also taken into account. In the Suzuki and Heck coupling reactions, TGAP cured by using Pd(PPh3)4 as polymerization initiator was investigated. In order to optimize the reaction conditions, the influences of different solvents, bases and other factors were considered. Hot filtration, dissolving/redeposition and poisoning tests were also carried out to distinguish the true active species in these C-C coupling reactions. In addition, competition reactions were performed in the Suzuki coupling of different substituted substrates with phenylboronic acid to compare the influence of substituents. In the hydrogenation reactions, TGAP containing palladium or niobium species prepared by using Pd(PPh ) or Nb(OEt) as initiators was investigated. Unsaturated esters and aldehydes can be quantitatively converted to the corresponding hydrogenation products under mild reaction conditions. Metal species leaching is extremely low and a long-term application is possible. Different magnetic catalysts were also prepared via homopolymerization by inclusion of magnetic particles and evaluated in the epoxidation of cyclohexene, Suzuki coupling and hydrogenation reactions. The approach for the immobilization of d-block metal compounds via homopolymerization of epoxy resins seems to allow the use of further metal compounds and extension of the concept to other catalytic reactions.
ER  -