Preparation of alkenyliron complexes from the addition of anionic nucleophiles to cationic vinylidene complexes

Article abstract of DOI:10.1021/om00084a009

The reaction of [CpFeCO(PPh₃)(C=CMe₂)]BF₄ with R₂Cu(CN)Li₂ (R = Ph, CH=CH₂) reagents leads to addition at the vinylidene α-carbon atom to produce CpFeCO(PPh₃)[η¹-C(R)=CMe₂] complexes. For R = CH=CH₂, this η¹-allyl complex smoothly converts into CpFe(PPh₃)(η³-CH₂CHC=CMe₂), a complex with an unusual η³-allyl ligand. Addition of [SPh]^- to the vinylidene complex yields CpFeCO(PPh₃)[C-(SPh)=Me₂]. The unsymmetrical vinylidene complex [CpFeCO(PPh₃){C=C(Ph)Me}][OSO₂CF₃] was prepared and reacts with Me₂Cu(CN)Li₂ to produce a 93:7 ratio of the Z:E isomers of CpFeCO-(PPh₃)[η¹-C(Me)=C(Ph)Me].