Chlorotrimethylsilane and Sodium Iodide: An Expedient Combination for the Chemo/Regioselective Dehalogenation of Benzothiazole and Thiazole Derivatives

The combination of chlorotrimethylsilane and NaI is disclosed as a reducing system for protodehalogenation of benzothiazole and thiazole derivatives; surprisingly, the alkoxy groups present in the system are unaffected. The optimized reaction conditions tolerate various functional groups and display good efficiency in the regioselective protodehalogenation of a variety of benzothiazole and thiazole derivatives. In addition, the potential application of the protocol was examined by comparing it with previously developed methods; in most of the cases, the present strategy resulted in better yields under milder condition. The mechanistic studies suggest that the reaction probably proceeds through a radical pathway.