Synthesis and reactions of nickel and palladium carbon-bound enolate complexes

Article abstract of DOI:10.1021/om00115a007

Nickel and palladium carbon-bound enolates of the general formula η⁵-C₅R₅(Ph ₃P)MCHR′COR″ (R = H, CH₃; R′ = H, CH₃; R″ = t-Bu, Ph, O-t-Bu) were prepared. Cp*(Ph₃P)NiCH₂CO₂-t-Bu (1e) was characterized by X-ray diffraction. Compound 1e crystallizes in the monoclinic space group P2₁/n with unit-cell dimensions a = 13.6110 (20) A?, b = 12.7454 (13) A?, c = 17.8571 (23) A?, β = 105.544 (11)°, Z = 4, observed data 4091, R = 4.53%, and R_w = 4.19%. Reactions of these nickel and palladium enolates with aldehydes and other electrophilic reagents were examined. The nickel ketone enolates were shown to react with 2 equiv of benzaldehyde to deliver products resulting from a Tischtschenko-type oxidation/reduction process. Cp(Ph₃P)NiCH₂CO-t-Bu reacts with phosphines (L) to yield paramagnetic nickel(I) complexes of general formula Cp(L)₂Ni.