The olefin metathesis reactions in dendrimers

The Olefin Metathesis Reactions in Dendrimers - Olefin metathesis reactions catalyzed by Ru benzylidene catalysts involving polymers and dendrimers have been investigated in our research group and are briefly reviewed. Dendrimers have been loaded at their periphery with ruthenium-chelating bis-phosphines, which leads to the formation of dendrimer-cored stars by ring-opening-metathesis polymerization (ROMP). CpFe+-induced perallylation of polymethylaromatics (Cp = eta(5)-C5H5) followed by ring-closing metathesis (RCM) and/or cross metathesis (CM) leads to poly-ring, cage, oligomeric and polymeric architectures. In the presence of acrylic acid or methacrylate, stereospecific CM inhibits oligomerization, and dendritic olefins yield polyacid dendrimers. Tungsten-catalyzed polymerization of alkynes coupled with electron-transfer-chain catalysis leads to much faster and cleaner polymerization than with an 18-electron tungsten catalyst alone.