Ruthenium‐Catalyzed ortho C−H Borylation of Arylphosphines

Efficient, phosphine‐directed ortho C?H borylation of arylphosphine derivatives was achieved using Ru catalysts for the first time. The reaction is applicable to various tertiary arylphosphine and arylphosphinite derivatives to give (o‐borylaryl)phosphorus compounds in high yields. This reaction enables easy access to a variety of functionalized phosphine ligands and ambiphilic phosphine boronate compounds, thus realizing a new late‐stage modification of phosphorus compounds.