Iron carbonyl anions lead derivatives

Of particular interest are phosphido-bridged derivatives of iron carbonyls, such as (OC)3 Fe(/i-PR2)2 Fe(CO)3. Upon reduction, these compounds give anions of the type [(OC)3 Fe(/i-PR2)2 Fe(CO)3] , in which the Fe —Fe bond is cleaved. The reduction with [BEt3H] leads to the formation of formyl complexes and the reaction with LiR furnishes acyl coordination compounds. In the reaction of... 

Iron carbonyl fragments have been incorporated into many heterometallic borane and carborane compounds. Those compounds are covered in Chapter 3.05 and will not be discussed here. Simple boryl adducts have been reported from the reaction of Na2Fe(CO)4 and ClBCat" (Cat = catecholate or a Bu-substituted derivative. Equation (8)). The same products can be obtained upon irradiating Fe(CO)s and Cat B-BCat" in toluene at 0°C. Reaction of the diboryl 6 with 1 equiv. of lithium bis(trimethylsilyl)amide in toluene solvent leads to removal of one boryl unit and the formation of an anionic iron boryl complex (Equation (9)). The anionic species can also be obtained by stoichiometric addition of the ClBCat complex to Na2Fe(CO)4. Reaction of [Fe(CO)4 B(3,5-/-Bu2-Cat) ] with ClSnMes gives the stannylated derivative Fe(CO)4 B(3,5-/-Bu2-Cat) (SnMe3). 

In (alkene)iron complexes, either neutral or cationic, the electron density at the alkene is reduced. This allows for nucleophilic addition to such complexes. For example, malonates are added to give ethyl malonate derivatives after aqueous workup. Reaction of the intermediate anionic T -alkyl-Fp complexes with alkyl halides leads to migratory insertion of a carbonyl ligand and provides acylated products (Scheme 4-73). ... 

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