Alkaline‐Earth Metal Mediated Benzene‐to‐Biphenyl Coupling

Abstract Complex [( DIPeP BDI)Ca] 2 (C 6 H ), with a C 2− dianion bridging two Ca 2+ ions, reacts benzene to yield (biphenyl) biphenyl ( BDI=HC[C(Me)N‐DIPeP] ; DIPeP=2,6‐CH(Et) ‐phenyl). The complex was also prepared by reacting ) or reduction of BDI)CaI] KC 8 in presence biphenyl. Benzene‐benzene coupling observed when the deep purple product ball‐milling DIPP BDI)CaI(THF)] K/KI extracted (DIPP=2,6‐CH(Me) ‐phenyl) giving crystalline BDI)Ca(THF)] (52 % yield). Reduction BDI)SrI] gave highly labile BDI)Sr] as black powder (61 yield) which rapidly and selectively (biphenyl). DFT calculations show that most likely route for formation is pathway attacks neutral benzene. This facilitated metal‐benzene coordination.