Easy synthesis of a self-assembled imine-based iron(II) complex endowed with crown-ether receptors

Herein we report that an imine-based iron complex decorated with crown-ether moieties self-assembles in CH3CN solution from three building blocks (namely Fe(CH3CN)2(OTf)2, 2-picolylamine and aldehyde 6a) added in the proper molar ratio (1:2:2, respectively). Aldehyde 6a, endowed with a benzocrown-ether receptor, can be prepared in two steps from commercial materials with high yields (79 %) and no need of chromatographic separations. The self-assembled complex is highly stable in CH3CN solution. The complex has been tested as catalyst for the oxidation of aromatic compounds endowed with primary ammonium anchoring group with H2O2. An unexpected yet moderate selectivity for remote meta over ortho hydroxylation was obtained, which is mainly due to the steric hindrance of the catalyst.