Determination of the Effect of Cation−π Interactions on the Stability of α-Oxy-Organolithium Compounds

Sn-Li exchange equilibria have allowed the quantification of the stabilizing effect of cation-pi interactions in organolithium chemistry. Stabilization energy data on the effect of Li-pi complexation of an aromatic ring or a CC double bond in organolithium compounds are presented. The amount of stabilization gained by complexation of the Li atom with a pi system in alpha-oxy-organolithium compounds is quite comparable to the one observed in systems containing Li-N or Li-O interactions.