CuI-Catalyzed Coupling of Aryl Iodides with Pinacolborane

Significance

Arylboronic acids have been applied to organic synthesis frequently in the last years as sources of nucleophilic aryl groups. The usual methods of their synthesis involve the formation of organometallic reagents (Li or Mg), which are often not compatible with the presence of functionalities. Arylboron pinacolates can completely substitute boronic acids for most reactions, but are significantly stable compounds. This method offers a useful procedure for their preparation, starting from easily available materials. The former analogous methodologies required substantial catalytic amounts of rare Pd. The use of inexpensive CuI for this purpose makes arylboronates now much more easily available compounds.