Facile α-β isomerisation of the σ-π phenylethenyl ligand at the diiron centre

Abstract

At 110 °C α-substituted [Fe₂(CO)₆(µ-PhCCH₂)(µ-PPh₂)] 1 is cleanly converted into the β-isomer [Fe₂(CO)₆(µ-HCCHPh)(µ-PPh₂)] 2, a process which is accelerated in the presence of arylphosphines; with P(OMe)₃ mono- and di-substituted adducts of 1 are isolated at 70 °C, which cleanly isomerise at higher temperatures.