2006/10/06 by Yasutomo Segawa, Makoto Yamashita, Kyoko Nozaki · 2 citations
Chemistry · #Organoboron and organosilicon chemistry #Coordination Chemistry and Organometallics #N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
paper · doi:10.1126/science.1131914
openalex publication_date 2006/10/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Nucleophilic, anionic boryl compounds are long-sought but elusive species. We report that reductive cleavage of the boron-bromine bond in N,N'-bis(2,6-diisopropylphenyl)-2-bromo-2,3-dihydro-1H-1,3,2-diazaborole by lithium naphthalenide afforded the corresponding boryllithium, which is isoelectronic with an N-heterocyclic carbene. The structure of the boryllithium determined by x-ray crystallography was consistent with sp(2) boron hybridization and revealed a boron-lithium bond length of 2.291 +/- 0.006 angstroms. The structural similarity between this compound and the calculated free boryl anion suggests that the boron atom has an anionic charge. The (11)B nuclear magnetic resonance spectrum also supports the boryl anion character. Moreover, the compound behaves as an efficient base and nucleophile in its reactions with electrophiles such as water, methyl trifluoromethanesulfonate, 1-chlorobutane, and benzaldehyde.