Co-oligomerization of diphenylketene and ethylene promoted by (η5-cyclopentadienyl)bis(ethylene)cobalt(I): synthesis and X-ray structure of a heterocycle containing cobalt(III)

Abstract

The complex [Co(cp)(C₂H₄)₂](cp =η⁵-C₅H₅) promotes the co-cyclization of two diphenylketenes and one ethylene molecule to form a chelate ring which is a structural model for some precursors of metal-catalyzed co-cyclization of different functionalities. The X-ray structure of the resulting complex [[graphic omitted]}(cp)], (2), shows the sequence of co-oligomerization of the three molecules. The cobalt is η⁵ bonded to cp, η³ bonded to an allyl group (arising from the rearrangement of an ethylene residue), and bonded to an oxygen atom. Complex (2) crystallizes in the triclinic space group P, with α= 12.664(4), b= 16.637(5), c= 10.378(4)Å, a= 93.60(4), β= 113.27(3), γ= 93.83(4)°, Z= 2, R= 0.065.