Au-Catalyzed Formal Allylation of Diazo(thio)oxindoles: Application to Tandem Asymmetric Synthesis of Quaternary Stereocenters

We report an efficient Au(I)-catalyzed formal allylation of diazo(thio)oxindoles using allyltrimethylsilane to give 3-allyl (thio)oxindoles, which are difficult to access by using traditional alkylation methods under basic conditions. The approach enables a highly stereoselective synthesis of quaternary (thio)oxindoles via a formal allylation-asymmetric Michael addition sequence. These adducts are versatile synthons for spirocyclic (thio)oxindoles. Initial biological studies reveal that chiral thiooxindoles show promising antiproliferation activity that is better than that of the corresponding oxindoles.

Automated summary

The study presents an efficient Au(I)-catalyzed formal allylation of diazo(thio)oxindoles, producing 3-allyl (thio)oxindoles which are challenging to access using traditional methods. This method allows for the stereoselective synthesis of quaternary (thio)oxindoles through a formal allylation-asymmetric Michael addition sequence, yielding versatile synthons for spirocyclic (thio)oxindoles. Initial biological investigations suggest that chiral thiooxindoles exhibit promising antiproliferation activity surpassing that of corresponding oxindoles.