Unveiling a PhSeSePh/I2-mediated radical cyclisation of 2-alkynyl-N-alkyl-N-tosylanilines: access to 3-sulfonyl indoles via 1,3 tosyl-relocation

Abstract

A PhSeSePh/I₂-mediated radical cyclisation of N,N-disubstituted o-alkynylanilines has been developed, offering an efficient route to 3-sulfonyl indoles through an unprecedented 1,3-tosyl transfer. The transformation commences with a vinyl radical intermediate that undergoes an intramolecular substitution reaction, constructing C–N and C–S bonds in a single step, confirmed by a sequence of control experiments.