This review presents highly enantioselective synthesis of functionalized helicenes and helicene-like mols. have been achieved via rhodium-catalyzed [2+2+2] cycloaddn. reactions. The rhodium-catalyzed enantioselective intramol. [2+2+2] cycloaddn. of 2-naphthol-linked triynes afforded [7]helicene-like mols. in good yields and ee values. The more sterically encumbered reaction, the rhodium-catalyzed enantioselective double intramol. [2+2+2] cycloaddn. of a 2-naphthol-linked hexayne, also proceeded to give a [11]helicene-like mol. with high ee value, although the product yield was low. Not only intramol. cycloaddn. reactions but also intermol. ones were accomplished by combinations of electron-rich tetraynes and electron-poor diynes to give [7]- and [9]helicene-like mols. and [7]helicenes in varying yields and ee values. [on SciFinder(R)]
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