Research news, Apr. 14th, 2015

 Synthesis, Structural Characterization, and Reactivity of a Fluorene-Based Calcium Oxycyclopentadienide Complex 

Baosheng Wei, Heng Li, Wen-Xiong Zhang,* and Zhenfeng Xi*

Organometallics 2015, 34, 1339-1344.

Direct deprotonation of 9-fluorenol with Ca[N(SiMe3)2]2 efficiently generated a fluorene-based calcium oxycyclopentadienide complex, which is the first alkaline earth metal complex containing an oxycyclopentadienyl dianion ligand. The η5, η1 and η2 interactions between the oxycyclopentadienyl dianion ligand and the calcium center were observed in the solid state. The calcium oxycyclopentadienide complex displayed reductive character and multiple reactive sites. Its reactivity towards a range of electrophiles, especially acid chlorides, was investigated and discussed in detail. A wide variety of fluorene derivatives were synthesized.