Solvent- and anion-dependent rearrangement of fluorinated carbene ligands provides access to fluorinated alkenes
Lewis M Hall1, Lucy M Milner, Sam J Hart
1Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK. jason.lynam@york.ac.uk john.slattery@york.ac.uk.
Abstract:
The construction of fluorocarbene ligands within the coordination sphere of transition metal complexes using sequential nucleophilic and electrophilic addition to a vinylidene complex is described. Reaction of [Ru(η5-C5H5)(dppe)([double bond, length as m-dash]C[double bond, length as m-dash]CPhF)][N(SO2Ph)2] with [NMe4]F results in nucleophilic attack of fluoride at the metal-bound carbon of the vinylidene ligand to give alkenyl complex [Ru(η5-C5H5)(dppe)(-CF[double bond, length as m-dash]CFPh)]. Subsequent eletrophilic fluorination with N-fluorobenzenesulfonimide (NFSI) results in the formation of the fluorinated carbene complex [Ru(η5-C5H5)(dppe)([double bond, length as m-dash]CF-CHFPh)][N(SO2Ph)2]. The fluorocarbene complexes undergo rearrangement to liberate free fluorinated alkenes, a process governed by the choice of solvent and anion, representing a new metal-mediated route to fluorinated alkenes from alkynes.
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