Easy Synthesis of a Self‐Assembled Imine‐Based Iron(II) Complex Endowed with Crown‐Ether Receptors. Issue 23 (4th June 2020)

• Record Type: Journal Article
• Authors: Capocasa, Giorgio; Di Berto Mancini, Marika; Frateloreto, Federico; Lanzalunga, Osvaldo; Olivo, Giorgio; Di Stefano, Stefano
• Is Part Of: European journal of organic chemistry. Issue 23(2020)
• Page Start: 3390
• Page End: 3397
• Publication Date: 2020-06-04
• Subjects: Imines -- Crown compounds -- Iron complexes -- Self‐assembly -- C‐H oxidation; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202000388
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : Herein we report that an imine‐based iron complex decorated with crown‐ether moieties self‐assembles in CH3 CN solution from three building blocks (namely Fe(CH3 CN)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 CH3 CN solution. The complex has been tested as catalyst for the oxidation of aromatic compounds endowed with primary ammonium anchoring group with H2 O2 . An unexpected yet moderate selectivity for remote meta over ortho hydroxylation was obtained, which is mainly due to the steric hindrance of the catalyst. Abstract : An iron(II) complex self‐assembles in solution from precursors which are easily synthesized from commercial materials. When used as a catalyst in the H2 O2 oxidation of some ω‐phenylalkylammonium salts, this complex shows an unnatural preference for meta over ortho hydroxylation, probably due to steric effects.