Cyclic Triolborates: Air‐ and Water‐Stable Ate Complexes of Organoboronic Acids

A borate in the hand is a convenient reagent for palladium- and copper-catalyzed CC and CN bond-forming reactions, especially when, like the title bench-stable complexes, it demonstrates high transmetalation efficiency. Cyclic triolborates can be synthesized readily from organoboronic acids (see scheme), can be handled and stored without special precautions, and are relatively soluble in organic solvents.