Friedel-Crafts reaction of indoles with alpha-amido sulfones in the presence of montmorillonite K-10 leads unexpectedly to 3-(1-arylsulfonylalkyl) indoles in good yield. The obtained products can be further desulfonylated under reductive or alkylative conditions giving linear and branched 3-substituted indoles.
Reaction of α-amido sulfones with functionalized nitrocompounds: a new two-step synthesis of <i>N</i>-alkoxycarbonyl-2,5-disubstituted pyrroles
sulfones with nitro ketals promoted by KF on alumina provides the corresponding adducts which, upon treatment with p-toluenesulfonic acid, generate the corresponding N-alkoxycarbonyl-2,5-disubstituted pyrroles. The latter transformation involves a cascade process including ketal cleavage, ring closure and final aromatization by nitrous acid elimination.