PPh3   Mediated Reductive Annulation Reaction between Isatins and Electron Deficient Dienes to Construct Spirooxindole Compounds.

Lei Zhang, Hong Lu, Guo-Qiang   Xu, Zhu-Yin Wang, and Peng-Fei Xu*

https://doi.org/10.1021/acs.joc.7b00595