Chlorostyrenes in Iron‐Catalyzed Biaryl Coupling Reactions

An effective protocol for iron-catalyzed biaryl syntheses by coupling chlorostyrenes with aryl Grignard reagents requires only mild reaction conditions and tolerates various functional groups. The underlying activation of deactivated aryl chlorides proceeds through a rate-determining coordination of the catalyst to the vinyl substituent and subsequent haptotropic migration along the conjugated π system to the site of CCl bond cleavage.