Larock indole synthesis

The Larock indole synthesis is a chemical reaction used to synthesize indoles from ortho-iodoanilines and a disubstituted alkyne.

An excess of alkyne, using potassium carbonate or potassium acetate as the base, and adding one equivalent of lithium chloride tend to give the best yields. Many functional groups are tolerated on the aniline and the alkyne.

Regarding the regioselectivity of the internal alkyne, the R-group with the largest steric bulk will end up in the R₂ position.

References

*Larock, R.C.; Yum, E. K.; Refvik, M. D.; "J. Org. Chem." 1998, "63", 7652.