Potassium fluorenide

A stable representative 31 of an intermediate 29 was obtained in 40% yield by Komatsu upon reacting Cjq with potassium fluorenide in the presence of neutral fluorene without rigorous exclusion of air (Scheme 10.5) [45]. 

The crystallisation of potassium fluorenide or 9-Bu -fluorenide from a mixture of THF, TMED and EtjO yielded [F1K(TMED)2] or [K(THF)2][ ii-9-Bu Fl][K(TMED)][p.-9-Bu Fl] (11). Both complexes were characterized by X-ray crystallography and by NMR spectroscopy (11) has a polymeric chain structure with K coordinated to two 6-membered rings from two bridging 9-Bu F1 units. ... 

Whereas sodium indenide was formed in tetrahydrofuran, the metalla-tion of filuorene was best carried out with sodium or potassium in dimethoxyethane or with potassium in diethyl ether. In either case the sodium indenide or sodium fluorenide was added to a suspension of zirconium tetrachloride in the respective solvents, whereupon a yellow or orange crystalline product was formed. The product could not be extracted with an organic solvent owing to the rapidity with which it decomposed in solution. The product could be recovered, however, by... 

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