Übergangsmetall‐katalysierte kondensations‐ und polykondensationsreaktionen

While metal-catalysed polymerizations are chain reactions with constant valence of the metal, metal-catalysed polycondensations are step polymerizations with changing valence of the metal. Taking as examples the Pd-catalysed vinyl polymerization of norbornene, the alternating copolymerization of ethylene and carbon monoxide, and the Heck reaction, the essential structural prerequisites of the catalyst to control those reactions are presented. Metal-catalysed polycondensations may occur as one- or two-electron processes. The oxidative polymerization of 2,6-dimethylphenol, and the Ni-catalysed polyphenylene synthesis are discussed