Creation of Nucleophilic Boryl Anions and Their Properties

A series of anionic boron compounds, possessing a polarized boron–metal bond, were synthesized and structurally characterized. Detailed analyses of these boryl anions using NMR spectroscopy, X-ray crystallography, reactivity with electrophiles, and DFT calculations revealed that these compounds have anionic and nucleophilic character on the boron center in contrast to conventional boron-containing molecules with a Lewis acidic character. Some applications of boryl anions toward organic synthesis, organometallic chemistry, and main group chemistry are also described.