Jiří Trekoval

Lithium-potassium exchange in alkyllithium/potassium t-pentoxide systems: XIV. Interactions of alkoxides

Abstract Benzylpotassium containing only traces of lithium compounds is formed in the reaction of alkyllithium, potassium alkoxide and toluene over broad ranges of molar ratios of the reaction components and reaction times. This confirms that metal-metal exchange is occurring under the conditions used. The potassium alkoxide is used in stoichiometric amount for the metallation of toluene and is not only a catalyst. Use of a larger excess of potassium alkoxide leads to formation of its adduct with benzylpotassium. Various mechanisms for the above reaction are considered and formation of lithium alkoxide is assumed to help drive the equilibria towards the observed products.

Interactions of alkoxides : XI. Reactions of substituted N-lithium amides with heavier alkali metal alkoxides. a novel method for the preparation of N-sodium and N-potassium dialkylamides

Abstract Reactions of substituted N -lithium amides (RR′NLi) with heavier alkali metal alkoxides give rise to the corresponding heavier alkali metal amides. In this way, some N -sodium and N -potassium dialkylamides may be advantageously prepared in the pure state. These amides are much more reactive than lithium amides and readily metalate compounds containing CH bonds as weakly acidic as those in toluene. Metalations can also be carried out directly using a mixture of lithium amide and a heavier alkali metal alkoxide. The reactivity of N -sodium diisopropylamide was increased by the presence of sodium t-butoxide. A medium strength absorption was observed in the IR spectra of substituted alkali metal amides in the range 2800–2450 cm −1 ; this absorption is due to the stretching vibrations of the CH bond under the influence of “anionic hyperconjugation”.

Ketones substituted with an alkali metal. Isolation and some properties

Abstract With lithium, sodium, or potassium some derivatives of aliphatic ketones have been isolated. Their IR spectra in various media have been recorded, and in strongly solvating solvents confirm the enolate structures. The interaction of metalated 2,2-dimethyl-3-butanones with t-butoxides of the same alkali metal was demonstrated. Lithio-2,2-dimethyl-3-butanone reacted with alkoxides of heavier alkali metals via a metal—metal exchange reaction with formation of sodio- or potassio-2,2-dimethyl-3-butanone.