Palladium(II)-Catalyzed Oxidative C-H/C-H Cross-Coupling of Heteroarenes

摘要

The structural motif with heteroaryl-heteroaryl bonds is a predominant substructure of many natural products, pharmaceuti-cals, and electronic materials. Conventional wisdom states that these carbon-carbon biheteroaryl linkages are forged via transition metal catalyzed cross-coupling of a heteroaryl halide or pseudohalide with a heteroaryl organometallic reagent. However, preactivation of heteroaromatic carbon fragments with metal-containing functionalities and halides may involve several synthetic steps. In particular, some important types of heteroaryl organometallic compounds have proven challenging to synthesize and may even be inadequately stable to participate in the cross-coupling process. Thus, catalytic oxidative C-H/C-H cross-coupling of two heteroarenes would be the most ideal strategy to solve the problems (Figure 1, C).