Abstract
For these years, transition metal-catalyzed organic reactions via C-H bond cleavage have attracted much attention from the atom- and step-economic point of view, and various catalytic processes involving different modes to activate the ubiquitously available bond have been developed. In our group, the palladium, rhodium or ruthenium-catalyzed oxidative couplings of various aromatic substrates bearing heteroatom-containing functional groups with alkynes and alkenes have been extensively investigated. In this presentation, I focus on less-expensive ruthenium catalysts [RuCl2(p-cymene)]2 for CH bond activation research. And we have developed a mild, atom- and step-economical method for synthesis of cinnolinium salts from annulation of aromatic azo compounds with alkynes via CH bond activation. Surprisingly, this protocol has been successfully applied to the synthesis of indoloindole derivatives; in the presence of Zn, cinnolinium salts undergo skeletal rearrangement to give bioactive indoloindoles. Further application of this methodology in natural product synthesis is in progress widely.