Boronic acids, metal mediated oxidation

The Ullmann reaction (79) and the metal mediated oxidative polymerization (20) were used for the synthesis. These methods are replaced by metal catalyzed reactions nowadays. Schluter and Wegner (27) used in 1989 the coupling of boronic acids described by Susuki (22) to synthesize soluble polyphenylenes. The Pd catalyzed reaction tolerates a large number of functional groups. The diaryl coupling of Kumada can be used as well to synthesize polyphenylenes (29,J0). 

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