Regioselective C-H Borylation of C (sp2)-H Bond

C-H activation reactions have become a powerful method to direct functionalization of alkyl, alkenyl, and aryl C-H bonds over the past few decades. Among of them, Iridium catalyzed transformation of aryl C-H bonds to C-B bonds is one of the most useful method. However, a central challenge in these reactions is controlling their site selectivity. Over the past decade, some methods have been developed to accomplish regioselective C-H borylation by catalysts or substrates modification. In this paper, some methods developed in recent years to realize ortho-, meta-, and para-selective C-H borylation will be summarized and their strategy and mechanism of these methods will be discussed.