Catalysis Letters, Vol.148, No.8, 2432-2445, 2018
Synthesis and Catalytic Activity of PolyHIPE-Supported NHC-Bearing Ruthenium Initiator for ROMP
Although generally the ruthenium based homogeneous catalysts are used to initiate metathesis reactions, immobilization of homogeneous ruthenium metathesis catalysts on various solid supports has attracted a lot of interest from the scientific community in recent years. In this article, the synthesis and applications of highly active polyHIPE-supported N-heterocyclic carbene ligand (NHC)-bearing ruthenium alkylidene metathesis catalysts were described. Open-celled porous polyHIPE foams having surface area of 575 m(2)/g were synthesized by polymerization of the continuous phase of w/o high internal phase emulsions. Then RuCl2(PCy3)(H(2)IMes)(=CHPh) complex was attached to porous polyHIPE solid supports via alkylidene exchange reactions to obtain new olefin metathesis catalysts. The amount of initiator loadings was determined by ruthenium analysis via ICP-OES and found to be 0.0336-0.0514 mmol/g. Subsequently, the activity of new catalysts was tested in ring opening metathesis polymerization of norbornene and a series of its derivatives. [GRAPHICS] .