Asymmetric Synthesis of Spiropyrazolones by Rhodium-Catalyzed C(sp<sup>2</sup>
)−H Functionalization/Annulation Reactions
作者:Jun Zheng、Shao-Bo Wang、Chao Zheng、Shu-Li You
DOI:10.1002/anie.201700021
日期:2017.4.10
Rhodium‐catalyzedC(sp2)−H functionalization reactions of 4‐aryl‐5‐pyrazolones followed by [3+2] annulation reactions with alkynes provide rapid access to highly enantioenriched five‐membered‐ring 4‐spiro‐5‐pyrazolones. The use of a chiral SCpRh catalyst enabled the synthesis of a large range of spiropyrazolones with all‐carbon quaternary stereogenic centers in up to 99 % yield and 98 % ee from readily