Sulfur-Directed Ligand-Free C–H Borylation by Iridium Catalysis

An iridium-catalyzed ortho C–H borylation reaction directed by cyclic dithioacetal moiety is disclosed. A series of borylation products were obtained in moderate to good yields under mild conditions in exclusive mono- and ortho-regioselectivity. Thus, the 1,3-dithiane or 1,3-dithiolane group serves as a remarkable effective directing group for C–H borylation without any ligand assistance. The further transformations of the borylation products...