Drawbacks of the dichlorinated system are the need for disubstitution to avoid a reactive position remaining vacant and problems occurring during some palladium catalyzed coupling reactions. Notably in the Sonogashira reaction, the selectivity for monosubstitution is low and the resulting products are hard to isolate in pure form. Also, Suzuki reactions only proceed at an acceptable rate under microwave irradiation. We are convinced that part of these ...
