TY - JOUR
T1 - Pentamethylcyclopentadienide in organic synthesis
T2 - Nucleophilic addition of lithium pentamethylcyclopentadienide to carbonyl compounds and carbon-carbon bond cleavage of the adducts yielding the parent carbonyl compounds
AU - Uemura, Minoru
AU - Yagi, Kazunari
AU - Iwasaki, Masayuki
AU - Nomura, Kenichi
AU - Yorimitsu, Hideki
AU - Oshima, Koichiro
N1 - Funding Information:
This work is supported by Grants-in-Aid for Scientific Research, Young Scientists, and COE Research from the Ministry of Education, Culture, Sports, Science, and Technology, Japan.
PY - 2006/4/10
Y1 - 2006/4/10
N2 - 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.
AB - 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.
KW - Carbon-carbon bond cleavage
KW - Carbonyl compounds
KW - Nucleophilic addition
KW - Pentamethylcyclopentadiene
KW - Protection
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U2 - 10.1016/j.tet.2006.01.097
DO - 10.1016/j.tet.2006.01.097
M3 - Article
AN - SCOPUS:33645003245
VL - 62
SP - 3523
EP - 3535
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 15
ER -