A Convenient Synthesis of Cyclopentadienylgallium – The Awakening of a Sleeping Beauty in Organometallic Chemistry

Solid “GaI” reacts with NaCp to yield (η 5 ‐cyclopentadienyl)gallium (GaCp) ( 1 ). During the synthesis the side product, CpGa→GaCp 2 I ( 2 ), with a rare gallium–gallium donor–acceptor bond could be isolated. The reaction of 1 with B(C 6 F 5 ) 3 affords CpGa→B(C 6 F 5 ) 3 ( 4 ). The molecular structures of 2 and 4 , which contain the first GaCp moieties, are presented. The convenient synthesis of 1 needs only standard laboratory equipment and certainly opens the door for 1 to become a versatile reagent in organometallic chemistry; awakening the sleeping beauty GaCp nearly twenty years after its initial discovery.