Ru-catalyzed step-growth

In this chapter, we report two solutions to this problem. Ru catalyzed step-growth copolymerizations of 4 -dialkylacetophenones, 4 -methoxyacetophenone or 4 -phenoxyacetophenone with a, -dienes proceed more readily and yield significantly higher molecular weight copolymers than those previously reported examples as in equation 3. Alternatively, treatment of the Ru catalyst with one equivalent of an alkene... 

A-A/B-B monomers, polycondensations, 157 A-B monomers, polycondensations, 157 AB monomers, self-polymerization via benzimidazole-activated ether synthesis, 266--274 Acetophenones Ru-catalyzed addition, 67-69 Ru-catalyzed step-growth copolymerization with a,(0-dienes for high-molecular-weight polymer synthesis, 99-112 4-(Acryloxy)benzoic acid, ordered polymer synthesis, 442-450 Acyclic diene metathesis polymerization cycle, 116,118/... 

Hydroarylation of alkenes is applied to achieve step-growth co-polymerization of aromatic ketones and ct,c< -dienes such as 3,3,6,6-tetramethyl-3,6-disila-l,7-octadiene and 1,3-divinyltetramethyldisiloxane. Co-polymerization of acetophenone and 3,3,6,6-tetramethyl-3,6-disila-l,7-octadiene is catalyzed by Ru species which has been previously activated by treatment with styrene, and a significantly high molecular weight co-polymer, co-poly(3,3,6,6-tetra-methyl-3,6-disila-l,8-octanylene/2-acetyl-l,3-phenylene), is obtained (Scheme 21 ).166... 

Metal catalyzed polymerizations are chain reactions necessitating a constant valence of the metal. In contrast to that metal catalyzed polycondensations are step growth reactions involving a change of the valence of the metal. Tuning of the reaction by structural variations of the metal catalyst are demonstrated with the Pd-catalyzed vinyl polymerization of norbomene, the alternating copolymerization of ethylene with carbon monoxide and the Heck reaction as examples. One and two electron processes can be involved in metal catalyzed polycondensations. The Heck reactions, the Ni-catalyzed synthesis of polyphenylenes, and Ru-catalyzed ArH-insertion reactions are discuss. ... 

Murai et al. have reported that dihydridocarbonyl/> /5(tiiphenylphosphine)ruthenium (Ru) catalyzes the addition of the ortho C-H bonds of acetophenone across the C-C double bonds of olefins such as trimethylvinylsilane to yield ortho alkyl substituted acetophenones (7-3). We have shown that this reaction can be applied to achieve step-growth copolymerization (cooligomerization) of aromatic ketones and a,co-dienes. For example, reaction of divinyldimethylsilane and acetophenone catalyzed by Ru at 150°C yields copoly(3,3-dimethyl-3-sila-1,5-pentanylene/2-aceto-1,3-phenylene), =... 

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