Nucleophilic addition of chromium carbene anions to the coordinated olefin in [Cp(CO) 2Fe(η 2-olefin)] + complexes and to the cyclohexadienyl ligand in [(η 5-cyclohexadienyl)(CO) 3Fe] +

Abstract

The chromium carbene anion [(CO) 5Cr  C(OMe)CH 2] − ( 2) has been found to add to the coordinated olefin in the complexes [(Cp(CO) 2Fe(η 2-olefin)] + (olefin  cis-2-butene, trans-2-butene, styrene) to form bimetallic chromium-iron complexes of the form (CO) 5Cr  C(OMe)CH2  CHRCHR′Fe(CO) 2Cp. Complex 2 also adds to the cyclohexadienyl ligand in [(η 5-cyclohexadienyl)Fe(CO) 3] + to form a crystallographically characterized bimetallic complex which has a Fe(CO) 3 unit coordinated to a [(CO) 5Cr  C(OMe)CH 2] − substituted cyclohexadiene ligand. A trimetallic Fe 2Cr complex with two (η 4-cyclohexadiene)Fe(CO) 3 groups attached to the β-carbon of the earbene ligand of the (CO) 5Cr  C(OMe)CH moiety has also been prepared, and two of the three possible stereoisomers of this complex have been crystallographically characterized.