An unprecedented thermodynamically unfavorable (4+1) deysmmetrizing spiroannulation through a thermodynamic enolate intermediate, enabling a single step synthesis of ubiquitous scaffolds such as all carbon chiral spirocycles, is disclosed. In this spiroannulation, we present a vinylogous organocatalytic enantioselective desymmetrizing (4+1) cycloaddition approach involving alkylidene malononitrile and cyclopent‐1,3‐dienone. This carbospiroannulation method produces functionally enriched spiro[4,4]nonane structures with three stereocenters, has been presented good to high yields and enantiomeric ratios. Detailed DFT calculations reveal an intriguing reaction mechanism, which validates our observations.

中文翻译：

---

解锁热力学烯醇酸盐，用于动力学控制的去对称乙烯基 （4+1） 碳螺体调节


公开了一种前所未有的热力学不利 （4+1） 去对称螺管化，通过热力学烯醇酸盐中间体实现无处不在的支架（例如所有碳手性螺环）的单步合成。在这个螺旋体测定中，我们提出了一种乙烯基有机催化对映选择性去对称 （4+1） 环加成方法，涉及烷基甲基丙二腈和环戊-1,3-二酮。这种碳螺烷化方法产生具有三个立体中心的功能丰富的螺[4,4]壬烷结构，已呈现出良好到高产率和对映体比率。详细的 DFT 计算揭示了一个有趣的反应机制，这验证了我们的观察结果。