A Mild Synthesis of 2-Substituted Benzothiazoles via Nickel-Catalyzed Intramolecular Oxidative C-H Functionalization.

A highly efficient synthetic method for the preparation of 2-aminobenzothiazoles starting from arylthioureas has been reported. By using a nickel catalyst, arylthioureas undergo intramolecular oxidative C-H bond functionalization, giving the desired 2-aminobenzothiazoles in good to excellent yields. This protocol features an inexpensive catalyst, low catalyst loading, mild reaction conditions, a short reaction time, and good to excellent yields, and it can be scaled up easily to a gram scale with almost no yields decreasing.