Lithium excess oxygen, reaction with

Peroxides contain the O—O, 02 group, in which the oxidation number of each oxygen is — 1, whereas normal oxides such as lithium oxide, Li20, contain oxide ions, 0 . The heavier members of the family (K, Rb, Cs) react with excess oxygen to form superoxides. These contain the superoxide ion, 02, in which the oxidation number of each oxygen is —5. The reaction with K is... 

Now the two parts, 184 and 199, must be linked in a controlled aldol reaction. The lithium enolate 200 reacts with the aldehyde in 199 in the presence of excess Lewis acid Me2AICI to give one diastereoisomer of 201 as the only product. Presumably the aluminium coordinates the tertiary amide and aldehyde oxygen atoms to hold the aldehyde in one Felkin conformation while it is attacked by the lithium enolate from one face only as sketched in 202. 

Cyclic alkyl aryl ethers lead also to functionalized organolithium compounds by reductive carbon-oxygen bond cleavage in arene-catalyzed lithiation process. Thus, the treatment of 2,3-dihydrobenzofuran (47) with an excess of lithium in the presence of a catalytic amount of DTBB in THF at 0°C gives the dianion (48) which after reaction with different carbonyl compounds and final hydrolysis with water leads to... 

Lithium perchlorate, LiClO, is an oxysalt that is a colorless, deliquescent crystal. Oxysalt per-ate compounds are loaded with excess oxygen and will readily give it up in a reaction. Lithium perchlorate is a powerful oxidizing agent. It has more available oxygen than does liquid oxygen on a volume basis. Lithium perchlorate has... 

The effect of lithium alkoxides on alkyllithium-initiated pol5nnerizations is important because these salts are ubiquitously present to some extent as impurities formed by the reactions with oxygen (13) (eq. 27) and hydroxylic impurities (eq. 28). In fact, it is common practice to utilize excess butyllithium, ie, more than the stoichiometric amount required to generate the required molecular weight, to scavenge impurities in the solvent and monomer feed. 

The 10-57-5-hydridosiliconate ion 62 is known in association with lithium,323 tetrabutylammonium,101 and bis(phosphoranyl)iminium93 cations. It is synthesized by hydride addition to the 8-.S7-4-silane 63, which is derived from hexafluoroacetone.101 Benzaldehyde and related aryl aldehydes are reduced by solutions of 62 in dichloromethane at room temperature101 or in tetrahydrofuran at 0°96 within two hours. The alkyl aldehyde, 1-nonanal, is also reduced by 62 in tetrahydrofuran at O0.96 Good to excellent yields of the respective alcohols are obtained following hydrolytic workup. The reactions are not accelerated by addition of excess lithium chloride,96 but neutral 63 catalyzes the reaction, apparently through complexation of its silicon center with the carbonyl oxygen prior to delivery of hydride from 62.101... 

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