Toward Ideal Arene Assembly: Catalytic C-H Bond Arylation of Aromatic Compounds

In this account, the early stages of our campaign (2006-2009) to develop catalysts able to realize ideal arene assembly through catalytic C-H bond arylation of aromatic compounds are described. New Rh, Ir, and Ni catalysts have been developed for the C-H bond arylation of heteroarenes with haloarenes. It was also found that Cu(OCOCF3)(2) can promote the C-H bond arylation of electron-rich arenes with aryl boronic acids. During these studies, we accidentally discovered that KOt-Bu alone can promote the C-H bond arylation of electron-deficient nitrogen heterocycles with haloarenes. Through a sequence of three consecutive bond-selective C-H arylations, a programmed synthesis of tetraarylthiophenes has been established. During this study, we discovered metal-and ligand-controlled regiodivergency in C-H bond arylation.