Preparation of 3-substituted-2-pyridin-2-ylindoles: regioselectivity of Larock's indole annulation with 2-alkynylpyridines

A regioselective Larock approach to 3-substituted-2-pyridin-2-ylindoles from 2-alkynylpyridines and 2-iodoanilines is described herein. The unexpectedly high regioselectivity can be rationalized by a combination of steric, coordinative, and electronic effects.