C–F sp2 bond functionalization mediated by niobium complexes

Abstract

Insertion chemistry of isocyanide molecules was used to functionalize C–F sp² bonds after their oxidative addition across the metal center in a β-diketiminate niobium(III) imido complex (BDI)Nb(N^tBu)(C₆H₆). The complexes formed, 3a–b ([BDI]Nb(PhCN)(N^tBu)(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.