Using Lithium-Cobalt Mixed-Metal Bases

5 Using Lithium-Cobalt Mixed-Metal Bases 

When used in THF at room temperature, the base prepared from LiTMP and CoBr in a 3 1 ratio proves capable of deprotometalating different methoxybenzenes. The generated aryhnetal species can be trapped by different electrophiles iodine, anisaldehyde, and chlorodiphenylphosphine to respectively generate the corresponding iodide, alcohol, and phosphine in high yields and benzo-phenone, benzoyl chloride, and allyl bromide to afford the expected alcohol, ketone, and allylated compound in moderate yields (Table 27.10). The side formation of symmetrical dimers was observed in the course of these reactions, in particular using aUyl bromide such a side reaction (reduced by using the base in excess) could be initiated by one-electron transfer from a cobaltate species to the electrophile. This lithium-cobalt base is not suitable for the functionalization of sensitive substrates such as ethyl benzoate [109,110]. 

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Therefore, melts-solvents of the first kind are of interest in the following scientific aspects determination of the acid-base product of the ionic solvent and estimation of the upper limit of acidity of these solvents (such as nitrates, sulfates). The decrease of stability of the solvent acid can be used for the stepwise decomposition of acidic solutions of cations and synthesis of complex oxide compounds and composites by coprecipitation [53-56], It is possible to obtain complex oxides containing alkali metals by precipitation of multivalent metal oxides with the alkali metal oxide as a strong Lux base, as was reported by Hong et al., who used 0.59LiNO3-0.41LiOH mixed melt to obtain electrochemically active lithium cobaltate, LiCo02 [57]. 

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