Development of Cycloisomerization with Rearrangement of a Tosyl Group Using N-Tosyl-o-allenylaniline

Sulfonyl indoles were synthesized by migratory cycloisomerization from the allene N-tosyl-o-allenylaniline. 3-Tosyl indoles or 4-tosyl indoles were selectively produced using a Pd catalyst or a Au catalyst, respectively.