Sodium indenide

Whereas sodium indenide displays a stereoselectivity similar to phenylzinc chloride (see Table 26), sodium cyclopentadienide and 3-trimethylsilylindene act like soft carbanions. Both substrates 10 and 12 undergo allylic substitution with net retention of configuration to 1127 and 1328, respectively, via attack on the ally ligands of the intermediate 7t-allylpalladium complexes anti to the metal. Again, the ratio of the two possible diastereomers of structure 13 is unknown. 

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... 

Tetracyclopentadienyl cerium and tetraindenyl cerium have been prepared as red-orange or yellow solids by interaction of cerium hexachloride dipyridinium complex with sodium cyclopentadienide or sodium indenide, respectively. Both compounds are described as stable against dilute acids and alkalis (Kalsotra et al., 1971a). 

Substituted cyclopentadienes also form metallic derivatives by direct reaction in the liquid phase with elemental lithium, sodium, and potassium. Thus, indene reacts with sodium to form sodium indenide (11,23,24) and lithium, sodium, and potassium react with fluorene (17, 25). Reaction of metals with substituted cyclopentadienes in the vapor phase has not been extended beyond methylcyclopentadiene. 

This deep purple compound, prepared from the reaction of iron(II) chloride and sodium indenide in THF, is moderately air stable. Attempts to oxidize it with various oxidizing agents only leads to complete destruction of the molecule, and no evidence for the formation of a bis-indenyliron(III) ion, analogous to the ferricinium ion, is obtained. The compound is quite soluble in polar organic solvents ... 

Trisindenyllanthanides, isolated as THF adducts (Tsutsui and Gysling 1969) were prepared by reaction of the anhydrous lanthanide trichlorides with sodium indenide ... 

Several types of supramolecular self-assembly are found in indenyl and fluorenyl complexes of the alkali metals. It has recently become possible for the first time to elucidate the crystal structures of unsolvated lithium indenide, [LiC9H7] , 26, and sodium fluorenide, [NaCoHgjn, 27 [24]. The crystal structure of 26 closely resembles that of unsolvated lithium cyclopentadienide because it also consists of a polymeric multidecker array in which the Li atoms are symmetrically coordinated by two rj -cyclopentadienyl rings of the indenyl ligands. In contrast, unsolvated sodium fluorenide, 27, forms a two-dimensional supramolecular structure in the solid state (Figure 7.3). In this unusual coordination polymer both the five- and six-membered rings of the fluorene system participate in coordination to sodium via and rj -interactions, respectively. 

The reactions between [Os(=N)Ph2(py)2][BF4] and sodium cyclopentadienide or potassium indenide result in the formation of the half-sandwich nitrido-Os(vi) complexes [Os(=N)GpPh2] and [Os(=N)( 7 -G9H7)Ph2], respectively/ ... 

Fulvenes are formed by the action of sodium cyclopentadienide, indenide, and fluorenide on chloroacetates RCHClOAc. Diaryl thioketones react with cyclopentadienyliron dicarbonyl and its molybdenum and tungsten analogues to yield 6,6-diaryl-fulvenes. The ester (20) dimerises stereoselectively to compound (21). Pyrolysis of phthalide at 740 C gives unstable fulveneallene... 

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