SUBSTITUENT EFFECTS ON THE ALKYL MIGRATION REACTION IN BENZYL MANGANESE(I) AND IRON(II) SYSTEMS

Several new benzyl compounds of the types [Mn(CH2C6H4X)(CO)(5)] and [C pFe{(CH2)(n)C6H4X}(CO)(2)] have been synthesised. The manganese deriva tives underwent a facile alkyl migration upon reaction with triphenylp hosphine to form cis-tetracarbonyl acyl compounds. A linear free energ y relationship was found to exist for this reaction and a value of -0. 94 was obtained for rho, the sensitivity parameter. The iron derivativ es were generally much less reactive, although the phenylethyl (n = 2, X = H) and phenylpropyl (n = 3, X = H) species did react with triphen ylphosphine to give phosphine substituted acyl compounds.