Thiophenes free radical synthesis

The two coupling reactions appear to have a common free-radical intermediate. Functional groups already in the aromatic compound, Axil, orient ortbo-para regardless of their nature. The reactions are most valuable for the preparation of biaryls of unequivocal structure when the hydrocarbon, Ar H, is unsubstituted. Good directions are given for the synthesis of p-bromobiphenyl (35%), and the literature of the reaction has been reviewed. Among the hydrocarbons prepared in this way are a- and yS-phenylnaphthalenes, o-, m-, and p-methylbiphenyls and m- and p-terphenyls. Thiophene and pyridine nuclei also have been aryl-ated. ... 

Dispersion polymerization has been also carried out to prepare PPy nanoparticle by several research groups. The synthesis of sterically stabi-hzed PPy colloid was carried out using a tailor-made reactive polymeric stabUizer [210]. In this study, a copolymer stabihzer was formed by free radical copolymerization of thiophene-based vinyhc monomer with various hydrophihc vinyl monomers such as 2-(dimethylamino)ethyl methacrylate, 2-vinylpyridine, and N-vinylpyrrohdone. These copolymer stabihzers were grafted onto the surface of PPy nanoparticle during dispersion polymerization and contributed to effective steric stabihzation of the nanoparticle. The resulting nanopartide had the size distribution in the range of 50-100 nm. 

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