Spirooxindole has been considered as the characteristic structural scaffold that can be found in a large number of natural or synthetic compounds with potent bioactivity profiles. However, common methods for synthesis of spirooxindole suffer from certain limitations such as complicated starting materials, multistep strategies, narrow scope of substrates or harsh reaction conditions. Therefore, developing a practical and efficient strategy to construction of spirooxindole has become a priority.

Prof. DAI Hui-Xiong and his colleagues from the Shanghai Institute of Materia Medica (SIMM) of the Chinese Academy of Sciences have been focused on late-stage functionalization of medicinal drugs and diversity-oriented construction of complicated skeletons via C–H activation. They have developed a Rh(III)-catalyzed domino annulation to give spirooxindole pyrrolone products. This research was published online in Angewandte Chemie International Edition.

This team found the reaction have several advantages: firstly, the reaction is under a mild condition and has a broad scope of substrates; secondly, the catalyst loading is lower than other reactions; lastly, the reaction shows good yield and excellent regioselectivity.

They showed that both aliphatic and aryl acrylamide substrates can be successfully converted into a series of spirooxindole derivatives. Moreover, the potential utility of this method in late-stage diversification was also exemplified in the introduction of spirooxindole pyrrolone skeleton into medicinal molecules pentoxifylline, endofolliculina and pregnenolon.

Finally, several control experiments suggested the reaction could involve a C–H activation, carbene insertion, Lossen rearrangement, and nucleophilic addition sequence.

The article linker： https://onlinelibrary.wiley.com/doi/10.1002/anie.201906589

Tandem C–H Activation/Lossen Rearrangement toward Spirooxindole Pyrrolone Construction (Image by MA Biao)

Contact：
DAI Huixiong （E-mail: hxdai@simm.ac.cn）