1. CeCl3/n‐BuLi: Unraveling Imamoto's Organocerium Reagent.
- Author
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Berger, Tassilo, Lebon, Jakob, Maichle‐Mössmer, Cäcilia, and Anwander, Reiner
- Subjects
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NUCLEAR magnetic resonance spectroscopy , *ION pairs , *LOW temperatures , *ORGANOLITHIUM compounds , *ALCOHOL , *KETONES - Abstract
CeCl3(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 7Li NMR spectroscopy, suggesting "Ce(n‐Bu)3(thf)x" or solvent‐separated ion pairs like "[Li(thf)4][Ce(n‐Bu)4(thf)y]" as the dominant species of the Imamoto reagent. The stability of complexes Li3Ln(n‐Bu)6(thf)4 increases markedly with decreasing LnIII size. Closer inspection of the solution behavior of crystalline Li3Lu(n‐Bu)6(thf)4 and mixtures of LuCl3(thf)2/n‐BuLi in THF indicates occurring n‐BuLi dissociation only at molar ratios of <1:3. n‐BuLi‐depleted complex LiLu(n‐Bu)3Cl(tmeda)2 was obtained by treatment of Li2Lu(n‐Bu)5(tmeda)2 with ClSiMe3, at the expense of LiCl incorporation. Imamoto's ketone/tertiary alcohol transformation was examined with 1,3‐diphenylpropan‐2‐one, affording 99 % of alcohol. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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