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%.
Chiral Atropisomeric 8,8′-Diiodobinaphthalene for Asymmetric Dearomatizing Spirolactonizations in Hypervalent Iodine Oxidations
作者:Toshifumi Dohi、Hirotaka Sasa、Keitaro Miyazaki、Mihoyo Fujitake、Naoko Takenaga、Yasuyuki Kita
DOI:10.1021/acs.joc.7b02037
日期:2017.11.17
A new type of binaphthyl-based chiral iodide functionalized at positions 8 and 8′ of the naphthalene rings has been found as a promising structural motif for the asymmetric hypervalentiodine(III) oxidations, specifically, for the dearomatizing spirocyclization of naphthol carboxylic acids showing expectedly better enantioselectivities versus other atropisomeric biaryls, i.e., a conventionally used