Triple carbon - fluorine bond activation for modification of metal ligands: Synthesis of the first eta(5)-C5Me4(CHPh2) transition metal complex

摘要

The eta(5)-(trifluoromethyl)tetramethylcyclopentadienyl iron complex, [(eta(5)-C5Me4CF3)Fe(CO)(2)Br] (2-Cp*(CF3)), undergoes reaction with benzene in the presence of AlCl3 to give the first transition-metal eta(5)-tetramethyl (diphenylmethyl)cyclopentadienyl complex, [(eta(5)-C5Me4CHPh2)Fe(CO)(3)IFF6 (3-Cp*(CHPh2)). This mechanistically complex, one-pot conversion involves a triple Lewis acid-mediated carbon-fluorine bond activation, including two defluorinative arylations and a hydrodefluorination. The structures of 2-Cp*(CF3) and 3-Cr*(CHPh2) are determined by X-ray crystallography and computation. This work exposes an Achilles' Heel for the eta(5)-[(trifluoromethyl)tetramethylcyclopentadienyl)] (Cp*(CF3)) ligand. (C) 2018 Elsevier Ltd. All rights reserved.