A versatile synthetic method for diiron bridging allenylidene complexes (η5-C5Me5)2Fe2(µ-CO)(CO)2(µ-η1-CCCR1R2)via nucleophilic addition to the ethynediyldiiron complex (µ-CC)[Fe(η5-C5Me5)(CO)2]2

Abstract

Addition of an excess amount of nucleophile (alkyllithium or LiHBEt₃) to the ethynediyldiiron complex (η⁵-C₅Me₅)(CO)₂Fe–CC-Fe(η⁵-C₅Me₅)(CO)₂1 in portions, affords a variety of diiron bridging allenylidene complexes (η⁵-C₅Me₅)₂Fe₂(µ-CO)(CO)₂(µ-CCCR¹R²)2(R¹,R²= H, Me, Bu, Ph) including the parent compound 2a(R¹= R²= H).