Regioselective Carbon–Carbon Bond Formation Reactions between TCNE or TCNQ and a Quinonoid RingThis work was supported by the Centre National de la Recherche Scientifique, the Ministère de la Recherche et des Nouvelles Technologies, and Clariant. We thank Prof. R. Welter and Dr. A. DeCian (ULP, Strasbourg) for the determination of the crystal structures, Dr. G. Royal (UJF, Grenoble) for preliminary electrochemical studies on compound 1 b, and the referees for constructive comments. TCNE=tetracyanoethylene, TCNQ=7,7′,8,8′-tetracyanoquinodimethane.