Fp group

Whereas photolysis of cyclohexasilanes usually results in silylene elimination and the successive formation of cyclopentasilanes and cyclotetrasilanes79, attachment of the Fp group to the ring as in 162 results in rearrangement to a silyl-substituted cyclopentasilane, 163, revealing that the presence of the transition metal alters the chemistry of these systems... 

Removal of the 0-substituted Fp group can be achieved by conversion into the cationic alkene-Fp complex using Ph3CPF6 and subsequent treatment with iodide, bromide or acetonitrile. Oxidative cleavage with ceric ammonium nitrate in methanol provides the methyl esters via carbon monoxide insertion followed by demetallation. The [3 + 2]-cydoaddition has been successfully applied to the synthesis of hydroazulenes (Scheme 1.11) [34]. This remarkable reaction takes advantage of the specific nucleophilic and electrophilic properties of V-allyl-, cationic t 5-dienyl-, cationic ri2-alkene- and ti4-diene-iron complexes, respectively. 

Propose a mechanism for the following multi-step reaction that involves nucleophilic participation of a remote it bond. Assume that in the first step compound 11 acts as a nucleophile. [Fp = CpFe(CO)2 = an arbitrary label to distinguish one Fp group from the other]... 

In accordance with results obtained from UV-Vis and Mossbauer spectroscopy, the pertinent CV data underline the fact that there is a noticeable transmission effect via the disilanyl bridge in 1. They show a distinct decrease in the HOMO-LUMO gap upon introduction of the Fp group... 

Nucleophilic attack on the 18-electron Fp(alkene) cations cannot proceed by coordination of the nucleophile to the metal unless displacement of a ligand also occurs (as with iodide). Generally, however, nucleophiles add to the alkene, yielding substituted alkyl derivatives (Fig. 7.9). Such addition always takes place stereospecifically trans to the metal. The Fp group can be removed from Fp—R in... 

FP Group PRODUCTION from Amount dissolved in fuel salt Amount separated to gas phase... 

Much better known, and more widely applicable are the complexes developed over many years by Rosenblum Fp alkenes.The Fp group is CpFe(CO)2. These are complexes of alkenes with the cyclopentadienyldicar-bonyliron moiety and carry a positive charge. They have been found to be much more stable than the simple... 

Herder WR, Sogah DY, Boettcher FP Group-transfer polymerization on a polymeric support, Macromolecules 23 1264—1268, 1990. 

Equilibrium distribution. Chemistry. The FPS group consists of the lanthanides and the elements in groups lA, IIA, and IIIA of the Periodic Table. Within this group the lanthanides account for about 94% of the total poisoning effect of the FPS elements. In the case of a typical 500-Mw reactor [1] the concentration of FPS elements in the bismuth amounts to about 17 ppm. To reduce this eoncentration to acceptable levels, a process has been developed whereby the FPS elements are oxidized by and then extracted into a fused salt. 

Grogger C, Fallmann H, Fiirpass G, Stiiger H, Kickelbick G (2003) The [Cp(CO)2Fe] (Fp) group as a donor in donor/acceptor substituted disilanes synthesis, structure and electronic properties of Fp-Si2Me4-CgH4CH C(CN)2. J Organomet Chem 665 186... 

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