Isomerization of a vinylcyclobutene to a cyclohexadiene: A nickel(I)-promoted rearrangement

Article abstract of DOI:10.1021/om00054a072

The nickel-promoted isomerization of a 3-vinylcyclobutene to the corresponding 1,4-cyclohexadiene was studied by using (PPh₃)₂Ni(C₂H₄) as the nickel source. Through the use of chemical and electrochemical experiments, it was determined that nickel(I) and not nickel(0) promotes this isomerization reaction at room temperature. The corresponding platinum-vinylcyclobutene complex 4 has been characterized by a single-crystal X-ray diffraction study: C₄₆H₄₂O₄P₂Pt, monoclinic, P2₁/n, with a = 10.774 (1) ?, b = 20.281 (4) ?, c = 18.297 (2) ?, β = 97.37 (1)°, Z = 4, R(F) = 0.0378, and R_w(F) = 0.0371.