The dearomative spirocyclisation of benzisoxazoles through a radical chain mechanism is described. Densely functionalised spirocycles were prepared in high yields by reacting benzisoxazole-tethered ynones with aryl thiols in 1,2-dichloroethane (DCE) at 60 °C. The identification of stabilising three-electron interactions was key to the development of this new radical cascade reaction. The obtained spirocyclic products were converted into other spirocyclic scaffolds through a two-step hydrogenolysis-cyclisation sequence.
Bibliographical noteFunding Information:
The authors would like to thank the Development and Promotion of Science and Technology Talents Project (DPST), Royal Thai Government. (N.I. EP/N035119/1), the University of York, and the University of Manchester for financial support. We would also like to thank Prof. Victor Chechik for helpful discussions.
© 2023 The Authors. European Journal of Organic Chemistry published by Wiley-VCH GmbH.
- ring expansion