New entry to pentamethylcyclopentadienyl iron chemistry and the methylene complexes [(η5-C5Me5)Fe(CO)(L)(CH2)]+(L = CO or PPh3)

Abstract

Na[(η⁵-C₅Me₅)Fe(CO)₂](1), a precursor of (η⁵C₅Me₅)Fe(CO)₂(CH₂OMe)(2), is conveniently obtained by Na-Hg reduction of [(η⁵-C₅Me₅)Fe(CO)₂]₂ overnight (20 °C), complex (2) yielding [(η⁵-C₅Me₅)Fe(CO)₂(CH₂PPh₃)]BF₄(3) upon acid treatment in the presence of PPh₃ and converting styrene quantitatively into phenylcyclopropane upon reaction with Me₃SiOSO₂CF₃ giving (η⁵-C₅Me₅)Fe(CO)₂(OSO₂CF₃)(4); photolysis of (2)+ PPh₃ produces (η⁵-C₅Me₅)Fe(CO)-(PPh₃)(CH₂OMe)(5) which upon acid treatment affords the methylene complex [(η⁵-C₅Me₅)Fe(CO)(PPh₃)(CH₂)]⁺(6).