Dual vicinal functionalisation of heterocycles via an interrupted Pummerer coupling/[3,3]-sigmatropic rearrangement cascade

An interrupted Pummerer coupling/[3,3]-sigmatropic rearrangement cascade allows the direct and metal free dual vicinal functionalisation of heterocycles. For example, C3 thio, C2 allyl indoles are prepared in one synthetic operation from the union of the parent indoles and allyl sulfoxides.