Cross-coupling reactions polymer conjugation

Discoveries made in the late 1970s of electrical conductivity in conjugated polymers spawned a monumental interest in the study of these materials, which are ideally suited for synthesis via cross-coupling reactions. Yamamoto was the first to realize this possibility with a regiochemicahy defined synthesis of poly(/ -phenylene) formed via the Kumada-Corriu protocol. Since then, various cross-coupling reactions have been applied in condensation polymerization reactions,with the Suzuki and Sonogashira protocols gaining the most widespread use. 

Cross-coupling reactions in the chemistry of silole-containing p-conjugated oligomers and polymers 02JOM(653)223. 

Conjugated polymers remain prime candidates for use as semiconductors in the emergent field of organic electronics [40-43]. Such materials are typically synthesized via polycondensation reactions, using a variety of aryl cross-coupling reactions. These methods are subject to problems that relate to, for example, the elimination of precursor functional groups. Unfortunately, the polymers produced via these methods often contain defects and unwanted branching, that may have deleterious effects on the conductive properties of the resultant material. 

T. Yamamoto, Cross-coupling reactions for the preparation of pi-conjugated polymers. J. Organomet. Chem., 653, 195-199 (2002). 

Conjugated polymers coordinated to chromium tricarbonyl were reported in 1989 134 xhese polymers were formed through a palladium-catalyzed cross-coupling reaction of T)%dichloroarene chromium tricarbonyl complexes with organostannane reagents, as shown in scheme 22. 

Over the past two decades, Suzuki polycondensation has become one of the most efficient methods for the synthesis of conjugated polymers. As another important cross-coupling protocol, the Suzuki-Miyaura cross-coupling reaction was invented by Suzuki and co-workers in 1979 The scope of the Suzuki reaction for synthetic applications has been surveyed in several excellent reviews by Kotha, Lahiri, Kashinath, Miyaura and Fu. The Suzuki-Miyaura cross-coupling reaction provided deeper insights into how to connect two specific sp -hybridized C-atoms more efficiently and under milder conditions. The Suzuki-Miyaura cross-coupling reaction was first used by Schlueter et al. to prepare poly(para-phenylene)s. ... 

Coffin et al. (2009) have shown the importance of the Stille cross-coupling reaction for the generation of conjugated polymers having fused aromatic heterocycles, especially thiophenes in their backbone. 

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