Asymmetric dearomative spirolactonization of naphthols using λ3-iodanes under chiral phase-transfer catalysis
作者:Kevin Antien、Guillaume Viault、Laurent Pouységu、Philippe A. Peixoto、Stéphane Quideau
DOI:10.1016/j.tet.2017.04.028
日期:2017.6
The asymmetric phase-transfer catalytic effect of chiral Cinchona alkaloid-derived quaternary ammonium salts was investigated in the context of the λ3-iodane-mediated dearomative spirolactonization of naphthols. The scope and limitations of this methodology were evaluated using various substrates, which were converted into spirolactones in good yields and with enantiomeric excesses up to 58%.
Abstract A series of planar chiral iodoarenes based on [2.2]paracyclophane was synthesized. An efficient asymmetric intramolecular oxidativelactonization of naphthols enabled by a combination of these chiral iodoarenes and mCPBA as oxidant is reported. This reaction proceeds under mild conditions, allowing the formation of spirolactones bearing a tetrasubstituted stereocenter in moderate yields and
METHOD FOR PRODUCING AROMATIC COMPOUND HAVING RING STRUCTURE THAT INCLUDES NITROGEN ATOM OR OXYGEN ATOM
申请人:Ishihara Kazuaki
公开号:US20130338371A1
公开(公告)日:2013-12-19
The invention is a method for efficiently producing an aromatic compound by an intramolecular cyclization reaction, the aromatic compound having a ring structure that includes a nitrogen atom or oxygen atom. An aromatic compound composed of tert-butyl-2-(3-oxo-3-phenylpropyl)phenyl carbamate or another aniline derivative or the like, or an aromatic compound composed of 3-(1-hydroxynaphthalene-2-yl)propionic acid or another naphthol derivative or the like is made to react in a system to which an oxidizing agent and a quaternary ammonium salt represented by general formula (1) are fed. In the formula, X is an iodine atom; and R
1
, R
2
, R
3
and R
4
are each independently a C
1-30
hydrocarbon group in which some hydrogen atoms are optionally substituted with halogen atoms, or R
1
and R
2
may be combine to form a divalent organic group bonded to a nitrogen atom, and R
3
and R
4
may combine to form a divalent organic group bonded to a nitrogen atom.
Enantioselective Kita Oxidative Spirolactonization Catalyzed by In Situ Generated Chiral Hypervalent Iodine(III) Species
作者:Muhammet Uyanik、Takeshi Yasui、Kazuaki Ishihara
DOI:10.1002/anie.200907352
日期:2010.3.15
The iodines(III) have it: The rational design of a conformationally flexible C2‐symmetric iodosylarene catalyst has been used for the enantioselectiveKitaoxidativespirolactonization. The reaction occurs through secondary n–σ* or hydrogen‐bonding interactions between the chiral catalyst and the substrate. Mes=mesityl (2,4,6‐trimethylphenyl).
Chiral hypervalent iodine-catalyzed enantioselective oxidative Kita spirolactonization of 1-naphthol derivatives and one-pot diastereo-selective oxidation to epoxyspirolactones
作者:Muhammet Uyanik、Takeshi Yasui、Kazuaki Ishihara
DOI:10.1016/j.tet.2010.04.060
日期:2010.7
hydrogen-bonding interactions as a chiral catalyst for the enantioselectiveKitaoxidativespirolactonization of 1-naphthol derivatives 5. Iodosylarenes 8 were generated in situ from iodoarenes 7 and mCPBA as a co-oxidant. Furthermore, epoxyspirolactone 15 was obtained by the one-pot oxidation of 5 with mCBPA in the presence of 7g. Thus, the enantioselectiveoxidation of 5 to 6 and the successive enantio-