Details
| Original language | English |
|---|---|
| Pages (from-to) | 6072-6083 |
| Number of pages | 12 |
| Journal | European Journal of Organic Chemistry |
| Issue number | 31 |
| Publication status | Published - 10 Sept 2010 |
Abstract
The complexation of phthalimide derivatives with hexacarbonylchromium in dibutyl ether/THF (10:1) afforded the corresponding tricarbonylchromium complexes, which were characterized spectroscopically. Subsequent nucleophilic addition with Grignard or organolithium reagents as well as with sodium tetrahydridoborate gave high yields of the corresponding anti adducts. However, in certain cases, addition of 1-lithio-1-methoxyallene, 1-propynyllithium, or ethenylmagnesium bromide, the unanticipated formation of the corresponding syn adducts was observed with the relative configuration of the propynyllithium adduct rac-20 confirmed by a crystal structure analysis. The unusual stereochemistry is explained by the intermediacy of a highly resonance-stabilized acyliminium ion formed from the original exo adduct. Finally, dehydration of the methyl adduct made available the exo-methylene derivative rac-37, bearing another fully sp2-hybridized ligand system. This compound was also characterized by a crystal structure analysis. The synthesis of the first phthalimide tricarbonylchromium complexes is reported. Nucleophilic addition to these complexes takes place at one of the imide carbonyl groups from the face opposite the Cr(CO)3 group to give endo-hydroxy products. In some cases, however, the unanticipated formation of the exo-hydroxy derivatives is observed as a result of isomerization following the original reaction.
Keywords
- Carbonyl ligands, Chromium, Nucleophilic addition, Reaction mechanisms
ASJC Scopus subject areas
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemistry(all)
- Organic Chemistry
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In: European Journal of Organic Chemistry, No. 31, 10.09.2010, p. 6072-6083.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Phthalimide tricarbonylchromium complexes
T2 - Synthesis, characterization, nucleophilic addition, and unanticipated syn adduct formation upon addition of propynyllithium
AU - Habib, Osama Mahmoud Ali
AU - Zhao-Karger, Zhirong
AU - Abdelhamid, Ismail Abdelshafy
AU - Wartchow, Rudolf
AU - Butenschön, Holger
PY - 2010/9/10
Y1 - 2010/9/10
N2 - The complexation of phthalimide derivatives with hexacarbonylchromium in dibutyl ether/THF (10:1) afforded the corresponding tricarbonylchromium complexes, which were characterized spectroscopically. Subsequent nucleophilic addition with Grignard or organolithium reagents as well as with sodium tetrahydridoborate gave high yields of the corresponding anti adducts. However, in certain cases, addition of 1-lithio-1-methoxyallene, 1-propynyllithium, or ethenylmagnesium bromide, the unanticipated formation of the corresponding syn adducts was observed with the relative configuration of the propynyllithium adduct rac-20 confirmed by a crystal structure analysis. The unusual stereochemistry is explained by the intermediacy of a highly resonance-stabilized acyliminium ion formed from the original exo adduct. Finally, dehydration of the methyl adduct made available the exo-methylene derivative rac-37, bearing another fully sp2-hybridized ligand system. This compound was also characterized by a crystal structure analysis. The synthesis of the first phthalimide tricarbonylchromium complexes is reported. Nucleophilic addition to these complexes takes place at one of the imide carbonyl groups from the face opposite the Cr(CO)3 group to give endo-hydroxy products. In some cases, however, the unanticipated formation of the exo-hydroxy derivatives is observed as a result of isomerization following the original reaction.
AB - The complexation of phthalimide derivatives with hexacarbonylchromium in dibutyl ether/THF (10:1) afforded the corresponding tricarbonylchromium complexes, which were characterized spectroscopically. Subsequent nucleophilic addition with Grignard or organolithium reagents as well as with sodium tetrahydridoborate gave high yields of the corresponding anti adducts. However, in certain cases, addition of 1-lithio-1-methoxyallene, 1-propynyllithium, or ethenylmagnesium bromide, the unanticipated formation of the corresponding syn adducts was observed with the relative configuration of the propynyllithium adduct rac-20 confirmed by a crystal structure analysis. The unusual stereochemistry is explained by the intermediacy of a highly resonance-stabilized acyliminium ion formed from the original exo adduct. Finally, dehydration of the methyl adduct made available the exo-methylene derivative rac-37, bearing another fully sp2-hybridized ligand system. This compound was also characterized by a crystal structure analysis. The synthesis of the first phthalimide tricarbonylchromium complexes is reported. Nucleophilic addition to these complexes takes place at one of the imide carbonyl groups from the face opposite the Cr(CO)3 group to give endo-hydroxy products. In some cases, however, the unanticipated formation of the exo-hydroxy derivatives is observed as a result of isomerization following the original reaction.
KW - Carbonyl ligands
KW - Chromium
KW - Nucleophilic addition
KW - Reaction mechanisms
UR - http://www.scopus.com/inward/record.url?scp=78349281183&partnerID=8YFLogxK
U2 - 10.1002/ejoc.201000758
DO - 10.1002/ejoc.201000758
M3 - Article
AN - SCOPUS:78349281183
SP - 6072
EP - 6083
JO - European Journal of Organic Chemistry
JF - European Journal of Organic Chemistry
SN - 1434-193X
IS - 31
ER -