Nucleophilic Aromatic Substitution Reactions in Cyclopentadienyliron Complexes of Chloroarenes and Nitroarenes

Abstract
N6-Chloroarene or nitroarene-n5-cyclopentadienyliron hexafluorophosphates react readily with CF3CH2OH/K2CO3 or with piperidine or piperazine to give nucleophilic aromatic substitutions with Cl or NO2 as the leaving group, further demonstrating an activation for SNAr reactions by complexation to the CpFe+ moiety. Similar nucleophilic aromatic substitution reactions can also occur with carbanion-enolate anion nucleophiles derived from acetylacetone, diethyl malonate and ethyl acetoacetate, leading to the formation of C-C bonds. Pyrolytic sublimation of these SNAr reaction products could liberate the free substituted arene ligands, such as the synthetically useful diethyl phenylmalonate and ethyl α-phenylacetoacetate.