Synthesis and Structures of Novel Chiral Cyclic Hypervalent Iodine(III) Reagents for Metal-Free Ligand-Transfer
Emmanuel Valzer1, Jean-Marc Sotiropoulos2, Karinne Miqueu2
1Univ. Bordeaux, ISM (CNRS-UMR 5255), Talence Cedex, France.
Abstract:
The preparation of novel chiral λ3-iodane reagents bearing transferable halogen-, oxygen- or carbon-based ligands is described. Among these hypervalent iodine(III)-based compounds are (i) the first chiral bis(cyano-λ3-iodane), whose bis(benziodazolone) structure is derived from an enantiopure cyclohexyldiamine-based bis(amidoiodoarene), and (ii) the two first chiral benziodoxolones bearing a carbon-based ligand (i.e., cyano and trifluoromethyl groups) together with a lactate moiety ortho-positioned to the iodine(III) atom. The proposed iodine-containing heterocyclic structures of these new λ3-iodanes are supported by x-ray diffraction analyses and DFT calculations. Their capacity to transfer their ligand(s) in an asymmetric fashion to different substrates (i.e., β-ketoesters, naphthols, and oxindoles) was also examined.
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