Participation of β‑Ketothioamides in N‑Heterocyclic Carbene- Catalyzed [3 + 3]   Spiroannulation: Asymmetric Synthesis of Functionalized Spiro-piperidinone   Derivatives

Hong Lu, Chang-Yin Tan, Huan-Xin Zhang,   Jia-Lu Zhang, Jin-Yu Liu, Hong-Yu Li, and Peng-Fei Xu*

https://pubs.acs.org/doi/10.1021/acs.joc.8b02520