Cyclopentadienide salts reactions

Not surprisingly the cyclopentadienide anion reacts readily with electrophilic reagents. With carbon dioxide it gives a dicarboxylic acid which dimerises [1,4]. It is acylated or aroylated by acid chlorides, no catalyst being required, to give diacyl [19,20] or diaroyl [21,22] derivatives which are monomeric. The monoacetyl-cyclopentadienide ion has been obtained by reaction with ethyl acetate in tetrahydrofuran [23]. With methyl chloroformate mono-and di- methoxycarbonyl)cyclopentadienide salts are formed [24]. 

Nickel plays a role in the Reppe polymeriza tion of acetylene where nickel salts act as catalysts to form cyclooctatetraene (62) the reduction of nickel haUdes by sodium cyclopentadienide to form nickelocene [1271 -28-9] (63) the synthesis of cyclododecatrienenickel [39330-67-1] (64) and formation from elemental nickel powder and other reagents of nickel(0) complexes that serve as catalysts for oligomerization and hydrocyanation reactions (65). 

Condensation Reaction of Cyclopentadienides with Azolium Salts. 130... 

Reaction of Cyclopentadienides or Their Nitrogen Analogs with Azolium and Dithiolium Salts... 

The reaction of 1,2-dithiolanes with 2- and 4-picolyllithium has been examined <96PS(112)101> and the reactions of thioanhydrides such as 94 with both thiols <95JOC3964> and amines <96TL5337> have been reported. Treatment of 1,2-dithiolium salts with lithium or thallium cyclopentadienide results in formation of a variety of bi-, tri- and tetracyclic products <96LA109>. Reaction of 95 with trimethyl phosphite gives some of the desired coupling product but also the phosphonates 96 <96PS(109)557>. 

Aryl-l,2-dithiolium salts are a source of either dithiatricyclodecadienes (29) or cyclopenta[fc]thiopyrans (30) depending on whether the initial ring opening resulting from reaction with a metal cyclopentadienide is followed by an intramolecular cycloaddition or a condensation <96LA109>. 

Reactions between salts of [m Jo-7-CBioHi3] and [Fc3(CO)i2] afford the mononuclear anionic iron compound [2,2,2-(CO)3-c/o5o-2,l-FeCBioHn], typically isolated as its [N(PPh3)2] salt (11) (Chart 4). No anionic triiron complex analogous to 5 and 7 is formed in this reaction. The anionic mononuclear iron, ruthenium and osmium complexes and the previously mentioned neutral mononuclear ruthenium dicarbollide complex 4, obtained from [Ru3(CO)i2] and /Jo-7,8-C2BgHi3, are iso-lobal with the cyclopentadienide species [Mn(CO)3(ri-C5H5)] and [Fe(CO)3 (il-CsHs)]. ... 

Reaction of the sulphonium salt (52) with cyclopentadienide ion leads to methylene-cyclopropene, though this can only be trapped in low yield by addition to cyclo-pentadiene 47). 

Silyl cyclopentadienes1,2 3 have been formed through the interaction of a cyclopentadienide prepared in situ with an appropriate silicon halide however, purification of the desired product required filtration, removal of solvent, and vacuum distillation at elevated temperatures. The synthesis of the silicon compounds, C5H5(SiH3) and C5H4(CH3)(SiH3), described here utilizes a low-temperature reaction between liquid bromosilane and the salt K[RC5H4] (where R = H, CH3), in a 1 2 mole ratio, respectively.4 5... 

Alkylution of cyclic I J-diketones The reaction of cyclic 1,3-diketones with thallium(l) ethoxidc, thallium(l) carbonate, or thallium(l) cyclopentadienide gives colorless, crystalline thallium(l) salts (2,408). These salts can be alkylated in nonpolar solvents (benzene, DME) to give products of O-alkylation in high yield, as illustrated... 

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