C-F Sp(2) Bond Functionalization Mediated by Niobium Complexes

Insertion chemistry of isocyanide molecules was used to functionalize C-F sp(2) bonds after their oxidative addition across the metal center in a β-diketiminate niobium(iii) imido complex (BDI)Nb(N(t)Bu)(C6H6). The complexes formed, 3a-b ([BDI]Nb(PhC[double bond, length as m-dash]N)(N(t)Bu)(F) (R = 1,6-diisopropylphenyl, tert-butyl), were characterized by NMR spectroscopy and X-ray analysis. Further treatment with phenylsilane induced H/F exchange under mild conditions, which was followed by hydride transfer to the inserted isocyanide. Divergent reactivity was observed when the two analogous aryl and tert-butyl isocyanide insertion products were treated with phenylsilane.