Interaction of alkoxides. XVI. New properties of complex bases formed from butyllithium and heavier alkali metal t-pentoxides at various alkoxide concentrations. Reaction with organic halogenides

Article abstract of DOI:10.1016/0022-328X(89)87137-2

Complex bases from organolithium compounds (RLi) and heavier alkali metal alkoxides (R'OM) possess high reactivities.The dependence of their properties on the ratio R'OM/RLi have been investigated.The rates of model reactions between complex bases and organic halides increase with increasing concentration of alkoxide in the complex base by a factor of up to 90.Variation of the concentration of alkoxide also affects the relative yields of the various products in these model reactions, because it affects differently the rates of the competing reactions.Thus in the reaction of the complex base with octyl bromide, the yield of dodecane (a product of C-C coupling) increases from 50 molpercent for x = 1 to 86 molpercent for x = 4.However, the effect of the alkoxide concentration is markedly dependent on the reactants and on the reaction conditions.The availability of new types of complex bases increases the possible uses of reagents of this general type in organic synthesis, and they may be regarded as a second generation of complex bases.