CeCl /n-BuLi: Unraveling Imamoto's Organocerium Reagent.

CeCl (thf) reacts at low temperatures with MeLi, t-BuLi, and n-BuLi to isolable organocerium complexes. Solvent-dependent extensive n-BuLi dissociation is revealed by Li NMR spectroscopy, suggesting "Ce(n-Bu) (thf) " or solvent-separated ion pairs like "[Li(thf) ][Ce(n-Bu) (thf) ]" as the dominant species of the Imamoto reagent. The stability of complexes Li Ln(n-Bu) (thf) increases markedly with decreasing Ln size. Closer inspection of the solution behavior of crystalline Li Lu(n-Bu) (thf) and mixtures of LuCl (thf) /n-BuLi in THF indicates occurring n-BuLi dissociation only at molar ratios of <1:3. n-BuLi-depleted complex LiLu(n-Bu) Cl(tmeda) was obtained by treatment of Li Lu(n-Bu) (tmeda) with ClSiMe , at the expense of LiCl incorporation. Imamoto's ketone/tertiary alcohol transformation was examined with 1,3-diphenylpropan-2-one, affording 99 % of alcohol.