Allyl halides, reaction with iron carbonyls

In a similar manner, Jt-allyl complexes of manganese, iron, and molybdenum carbonyls have been obtained from the corresponding metal carbonyl halides [5], In the case of the reaction of dicarbonyl(r 5-cyclopentadienyl)molybdenum bromide with allyl bromide, the c-allyl derivative is obtained in 75% yield in dichloromethane, but the Jt-allyl complex is the sole product (95%), when the reaction is conducted in a watenbenzene two-phase system. Similar solvent effects are observed in the corresponding reaction of the iron compound. As with the cobalt tetracarbonyl anion, it is... 

In other variations ketones are produced. The acyliron monoanion may be alkylated again with another alkyl halide to form a transient acyl-alkyl iron intermediate, which rapidly decomposes into ketone and the polynuclear iron carbonyl complex. This reaction is limited, however, because only very reactive alkylating agents such as methyl, allyl, and benzyl halides will react with the weakly nucleophilic acyliron monoanions ... 

Of considerably greater interest is 77-allyl ligand transfer from one metal to another. Although the examples of such reactions are rather few they have been studied in detail. The first example of a 7r-allyl ligand transfer from one metal to another was reported by Nesmeyanov, Rubezhov, and Gubin (156). Iron carbonyls were found to react with some substituted binuclear 77-allylpalladium halides in benzene at room temperature, giving the respective 77-allyliron derivatives ... 

The preparation of bis (r 3-aiiyi)iron(II) complexes of the type [Fe(ri3-C3H5)2(PMe3)2] has been reported and their reactions with 1,3-dienes to form a mixture of products were described. The reaction of allyl halides with salts of [Fe(CO)3(NO)]- afforded [PeCli -allyl)(CO)2(NO)] complexes, which on treatment with l,2-bis(diphenylphosphino)ethane gave P,Y-unsaturated acyl iron complexes in good yields via regioselective carbonylation with retention of configuration of the allylic double bond. The same [Fe(Ti3-allyl)(CO)2(NO)] complexes were... 

---