Pentamethylcyclopentadienide in organic synthesis: Nucleophilic addition of lithium pentamethylcyclopentadienide to carbonyl compounds and carbon-carbon bond cleavage of the adducts yielding the parent carbonyl compounds

Minoru Uemura, Kazunari Yagi, Masayuki Iwasaki, Kenichi Nomura, Hideki Yorimitsu, Koichiro Oshima

Research output: Contribution to journalArticle

8 Citations (Scopus)


Lithium pentamethylcyclopentadienide (C5Me5Li, Cp*Li) reacted with aromatic aldehyde to provide the corresponding carbinol in excellent yield. The carbinol returns to the parent aldehyde and pentamethylcyclopentadiene upon exposure to acid or due to heating. Chlorodimethylaluminum is essential as an additive to attain the nucleophilic addition of Cp*Li to aliphatic aldehyde. The carbinol derived from aliphatic aldehyde returns to the parent aldehyde and pentamethylcyclopentadiene by the action of a catalytic amount of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The reversible addition/elimination of the Cp* group can represent a protection of aldehyde. Mechanistic details of the carbon-carbon bond cleavage are also disclosed.

Original languageEnglish
Pages (from-to)3523-3535
Number of pages13
Issue number15
Publication statusPublished - Apr 10 2006
Externally publishedYes



  • Carbon-carbon bond cleavage
  • Carbonyl compounds
  • Nucleophilic addition
  • Pentamethylcyclopentadiene
  • Protection

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

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