Chiral Helical Oligotriazoles: New Class of Anion-Binding Catalysts for the Asymmetric Dearomatization of Electron-Deficient N-Heteroarenes
Chiral Helical Oligotriazoles: New Class of Anion-Binding Catalysts for the Asymmetric Dearomatization of Electron-Deficient N-Heteroarenes
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DOI：
10.1021/ja507940k
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发表时间：
2014-10-08
影响因子：
15
通讯作者：
Mancheno, Olga Garcia
中科院分区：
文献类型：
--
作者：
Zurro, Mercedes;Asmus, Soeren;Mancheno, Olga Garcia
螺旋手性和选择性阴离子结合过程是自然界中促进高对映选择性化学反应的关键策略。尽管已经做出了巨大的努力来开发简单的螺旋手性系统，从而在不对称催化和合成中开辟了新的可能性，但合成的寡聚和聚合物螺旋手性催化剂的有效使用仍然非常具有挑战性并且相当不寻常。本工作中，我们开发了结构独特的手性三唑低聚物作为基于C-H键的阴离子结合催化剂，用于N-杂芳烃的不对称脱芳构化反应。这些旋转柔性催化剂在与氯阴离子结合时采用增强的手性螺旋构象，从而允许通过具有预先形成的离子底物的紧密手性阴离子对络合物进行高水平的手性转移。这种方法提供了一个简单和有效的入口，合成手性（生物活性）杂环化合物，从简单和丰富的杂芳烃具有附加的合成价值。
Helical chirality and selective anion-binding processes are key strategies used in nature to promote highly enantioselective chemical reactions. Although enormous efforts have been made to develop simple helical chiral systems and thus open new possibilities in asymmetric catalysis and synthesis, the efficient use of synthetic oligo- and polymeric helical chiral catalysts is still very challenging and rather unusual. In this work, structural unique chiral oligotriazoles have been developed as C-H bond-based anion-binding catalysts for the asymmetric dearomatization of N-heteroarenes. These rotational flexible catalysts adopt a reinforced chiral helical conformation upon binding to a chloride anion, allowing high levels of chirality transfer via a close chiral anion-pair complex with a preformed ionic substrate. This methodology offers a straightforward and potent entry to the synthesis of chiral (bioactive)heterocycles with added synthetic value from simple and abundant heteroarenes.