Catalyst‐Free Hydroarylation of in situ Generated ortho‐Quinone Methide (o‐QM) with Electron‐Rich Arenes in Water.

We report the first C–H hydroarylation of in situ generated ortho-quinone methides with electron-rich arenes. The reaction takes place in water without any catalyst, and is highly regioselective. Ionic and non-ionic additives provide an increase in reaction rate, yield, and regioselectivity.