Reduction of borazines mediated by low-valent chromium species.

Recharging spent BN fuel: {Cr(CO)(3)} mediates the reduction of borazines by hydride and methyl nucleophiles to generate anionic complexes of dearomatized hexamethylborazine. Subsequent quenching leads to the release of a substituted cyclotriborazane, successfully demonstrating the stepwise reduction of a B=N bond.