Synthesis, alkylation, crystal structure and molecular mechanics investigations of the (methylthio) acetyliron complex [(η5-C5H5)Fe(CO)(PPh3)COCH2SCH3]

The air stable (methylthio)acetyliron complex 4 was obtained by methylthiolation with dimethyldisulphide of the anion generated from acetyliron complex 1 with butyllithium. Alkylthiolation could not be achieved with a number of thiolating reagents 5–11. The enolate generated from 4 reacted readily and with high stereoselectivity with alkyl halides and with aldehydes. X-ray structural determination confirmed the pseudo-octahedral structure of 4. Decomplexation of benzylation products 16a and of aldol 18f yielded several products, the majority of them without sulphur atoms.