ABSTRACT
This chapter presents an overview of the direct activation of C–H bonds and the proposed mechanisms of direct arylation for small molecules. It explains the optimization of reaction conditions in the context of maximizing molecular weights while limiting the occurrence of defects. The chapter analyses both the potential of the direct (hetero)arylation polymerization (DHAP) reaction and some of the unanswered questions regarding this developed technique. It describes the role each of these ingredients plays in the quality of polymers prepared by DHAP. The direct arylation mechanism proceeds along the same general lines as the vast majority of other transition-metal-catalyzed cross-coupling reactions: oxidative addition, transmetalation, and reductive elimination. The challenge of coupling selectivity in polymer synthesis as opposed to analogous transformations of small molecule substrates is that the product of any undesired secondary reaction which is present in a cross-coupling catalytic system will exist in the resulting polymer material.
