Herein, we report an efficient approach to synthesizing hybrid 3‐spiropiperidines heterocycles that incorporate both 3‐isochromanone and 3‐isoindolinone units through a one‐pot, double cascade reaction facilitated by an economical K₂CO₃/TBAB catalytic system. By examining the nucleophilicity of the lactone 3‐isochromanone, we developed a cascade reaction pathway that first generates a bi‐nucleophilic hybrid intermediate, which then undergoes [3+3] spirocyclization with α,β‐unsaturated aldehydes. The regioselectivity of the spirocyclization strongly depends on the substitution pattern of lactam ring. The process exhibits high diastereoselectivity, even with the formation of three or four stereocenters, including two contiguous quaternary carbons. These sequential cascade reactions were successfully scaled up, and the subsequent reactivity was readily analyzed, enabling the transformation of existing functional groups into valuable new functionalities.

中文翻译：

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区域和非对映选择性一锅双级联杂化形成/[3+3] 螺环化，用于在相转移条件下合成 3-螺哌啶。


在此，我们报道了一种合成杂化 3-螺哌啶杂环的有效方法，该方法通过经济的 K₂CO₃/TBAB 催化系统促进的一锅双级联反应结合 3-异色酮和 3-异吲哚酮单元。通过检查内酯 3-异色酮的亲核性，我们开发了一种级联反应途径，该途径首先产生双亲核杂化中间体，然后与 α，β-不饱和醛发生 [3+3] 螺环化。螺环化的区域选择性在很大程度上取决于内酰胺环的取代模式。该工艺表现出高非对映选择性，即使形成三个或四个立体中心，包括两个连续的季铵碳。这些连续级联反应被成功放大，随后的反应性很容易被分析，能够将现有的官能团转化为有价值的新功能。