According to researchers Makoto Yamashita and his colleagues at the University of Tokyo, Japan, a molecule that hosts a negatively-charged boron atom could prove to be an exciting addition to the chemist's toolbox. Recently they have isolated the anion as its lithium salt.
Lithium can partner with many boron's neighbors in the periodic table, such as nitrogen in lithium amide and carbon in methyllithium. However, there have been no direct observations of the equivalent boryllithium compounds containing a negative boron atom.
This type of boron anion shares the same number of valence electrons as its popular carbon cousin, the N-heterocyclic carbene. The Tokyo team demonstrated boryllithium's nucleophilic prowess in reactions with n-butyl chloride and benzaldehyde.
This work opens the door to new pathways in boron chemistry that will substantially impact organic synthesis in general.
Ref: Makoto Yamashita and colleagues at the University of Tokyo, Japan. Science 2006, 314, 113.