Lewis Acid-Base Interaction-Controlled ortho-Selective C-H Borylation of Aryl Sulfides

An iridium/bipyridine-catalyzed ortho-selective C-H borylation of aryl sulfides was developed. High ortho-selectivity was achieved by a Lewis acid-base interaction between a boryl group of the ligand and a sulfur atom of the substrate. This is the first example of a catalytic and regioselective C-H transformation controlled by a Lewis acid-base interaction between a ligand and a substrate. The C-H borylation reaction could be conducted on a gram scale, and with a bioactive molecule as a substrate, demonstrating its applicability to late-stage regioselective C-H borylation. A bioactive molecule was synthesized from an ortho-borylated product by converting the boryl and methylthio groups of the product.