Spiro skeletons have emerged as a privileged class of chiral carriers across various research fields, including asymmetric catalysis and functional materials, due to their remarkable configurational rigidity. However, limited structural diversity of spiro frameworks significantly restricts the expansion of their applications. Here we present a new class of axially chiral spiro‐bisindole frameworks and report their first enantioselective construction via a chiral phosphoric acid‐catalyzed intramolecular dehydrative cyclization reaction. Unlike the classical SPINOL backbone, incorporation of indole moieties in place of phenol enhances the nucleophilicity of ketone substrates, thereby eliminating the need for a tedious pre‐activation process. By leveraging the retained active sites of indole, the resulting highly enantioenriched spiro‐bisindoles can be rapidly transformed into other valuable structures. More importantly, axially chiral fluorescent molecules with good asymmetry factors and quantum fluorescence efficiency are readily accessed, opening a new avenue for developing chiral fluorescent materials. Control experiments demonstrate the pivotal role of both unmasked N‐H bonds in achieving good efficiency and enantiocontrol.

中文翻译：

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轴向手性螺-双吲哚的有机催化不对称构建及应用


由于其卓越的构型刚度，螺状骨架已成为各种研究领域的一类特权手性载体，包括不对称催化和功能材料。然而，spiro 框架有限的结构多样性极大地限制了其应用的扩展。在这里，我们提出了一类新的轴向手性螺-双吲哚框架，并报告了它们通过手性磷酸催化的分子内脱水环化反应的第一个对映选择性结构。与传统的 SPINOL 骨架不同，掺入吲哚部分代替苯酚增强了酮底物的亲核性，从而消除了繁琐的预活化过程。通过利用吲哚保留的活性位点，所得的高度对映体富集的螺-双吲哚可以迅速转化为其他有价值的结构。更重要的是，具有良好不对称因子和量子荧光效率的轴向手性荧光分子很容易获得，为开发手性荧光材料开辟了一条新途径。对照实验表明，两种未掩蔽的 N-H 键在实现良好效率和对映体控制方面起着关键作用。