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Chiral Hypervalent Iodine(IIII) Catalysis

  • School of Engineering/Graduate School of Engineering
  • Department of Molecular and Macromolecular Chemistry
  • Research Group of Molecular Chemistry
  • (Laboratory of Catalysis in Organic Synthesis)

Kazuaki Ishihara [Professor]

http://www.ishihara-lab.net/english/

  • School of Engineering/Graduate School of Engineering
  • Department of Molecular and Macromolecular Chemistry
  • Research Group of Molecular Chemistry
  • (Laboratory of Catalysis in Organic Synthesis)

Muhammet Uyanik [Assistant Professor]

Outline of Seeds

We designed C2-symmetric and conformationally flexible hypervalent organoiodine(III) oxidation catalysts. Inexpensive lactate or 2-amino alcohol were used as a chiral source for the 1st and 2nd generation catalysts, respectively. Active iodine(III) species can be generated in situ from conformationally flexible chiral iodoarene in the presence of m-CPBA as an oxidant. The catalytic oxidative dearomatization of phenols by using these chiral organoiodines gave the desired cyclohexadienone spirolactones and the subsequent DielsAlder adducts with excellent enantioselectivities. Specially, the substrate scope can be expanded to the low-reactive phenols by using high-reactive 2nd generation catalyst. These reactions can be applied to the enantioselective synthesis of biologically active spirolactones. Moreover, our conformationally flexible chiral organoiodine catalysts have succesfully been applied to various enantioselective oxidative transformation reactions.

Novelty and originality of this research

In contrast to conventional methods using toxic heavy metal oxidants or precious tansition metal catalysts, we developed an enviromentally friendly enantioselelective oxidation process by using hypervalent organoiodine(III) compounds as a chiral organocatalysts. C2-symmetric chiral iodoarenes consist of three units, including an iodoaryl moiety, chiral linkers and subfunctional groups. These units can be easily combined to give a wide variety of chiral iodoarenes. A suitable chiral environment around iodine(III) center can be constructed via enzyme-like intramolecular non-bonding secondary interactions. Moreover, additional achiral alcohols play crucial roles in the enantioselectivity and turnover frequency (TOF) of hypervalent organoiodine catalysis.

Application and research area for Industry collaboration

Enantioselective oxidative dearomatization to spirolactones

Key Takeaway

Metal-free highly enantioselective oxidation catalysis for the synthesis of spirolactones

Keywords

hypervalent iodine, enantioselective oxidation catalysis, oxidative dearomatization, phenol, spirolactone

Technologies

  • Enantioselective oxidation, Oxidative dearomatization

Patents

  • JP5747332(B2)
  • JP5688647(B2)

Monographs, Papers and Articles

  • M. Uyanik, T. Yasui, K. Ishihara, Angew. Chem. Int. Ed. 2010, 49(12), 2175-2177.
  • M. Uyanik, T. Yasui, K. Ishihara, Tetrahedron, 2010, 66(31), 5841-5851.
  • M. Uyanik, T. Yasui, K. Ishihara, Angew. Chem. Int. Ed. 2013, 52(35), 9215-9218.
  • M. Uyanik, T. Yasui, K. Ishihara, Wako Junyaku Jiho. 2011, 79(2), 2-5.