Ruthenium Catalyzed Intramolecular C-S Coupling Reactions: Synthetic Scope and Mechanistic Insight

A ruthenium catalyzed intramolecular C-S coupling reaction of N-arylthioureas for the synthesis of 2-aminobenzothiazoles has been developed. Kinetic, isotope labeling, and computational studies reveal the involvement of an electrophilic ruthenation pathway instead of a direct C-H activation. Stereo electronic effect of meta-substituents on the N-arylthiourea dictates the final regioselective outcome of the reaction.