Details
| Original language | English |
|---|---|
| Pages (from-to) | 2719-2727 |
| Number of pages | 9 |
| Journal | European Journal of Organic Chemistry |
| Issue number | 12 |
| Publication status | Published - 23 Dec 1998 |
Abstract
Addition of carbon nucleophiles to (benzocyclobutenedione)tricarbonylchromiuni(0) (4) results in the formation of exo mono- and diadducts as well as 1,2-diketones as the consequence of proximal ring-opening reactions. In one case the unexpected formation of benzocycloheptenedione complexes is observed. Treatment of 4 with an excess of 1-ethoxy-1-lithioethene gives the product of a dianionic oxy-Cope rearrangement followed by an intramolecular aldol addition. This is also the case with lithiated methoxyallene, and as the result the first head-to-head coupling product 12 of two methoxyallene molecules is isolated in good yield. 12 is used as a diene in Diels-Alder cycloadditions, and its molecular structure is compared to that of the similar molecule 13, lacking the two exo methylene substitutents.
Keywords
- Benzocyclobutene, Benzocycloheptenedione, Chromium, Dianionic Oxy-Cope Rearrangement, Methoxyallene
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. 12, 23.12.1998, p. 2719-2727.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Addition and Ring Expansion Reactions of Tricarbonyl-(1,2-dioxobenzocyclobutene)chromium(0) with Carbon Nucleophiles
T2 - Unexpected Formation of Benzocycloheptene Derivatives and the First Head-to-Head Coupling of Two Methoxyallene Molecules
AU - Voigt, Beate
AU - Brands, Michael
AU - Goddard, Richard
AU - Wartchow, Rudolf
AU - Butenschön, Holger
PY - 1998/12/23
Y1 - 1998/12/23
N2 - Addition of carbon nucleophiles to (benzocyclobutenedione)tricarbonylchromiuni(0) (4) results in the formation of exo mono- and diadducts as well as 1,2-diketones as the consequence of proximal ring-opening reactions. In one case the unexpected formation of benzocycloheptenedione complexes is observed. Treatment of 4 with an excess of 1-ethoxy-1-lithioethene gives the product of a dianionic oxy-Cope rearrangement followed by an intramolecular aldol addition. This is also the case with lithiated methoxyallene, and as the result the first head-to-head coupling product 12 of two methoxyallene molecules is isolated in good yield. 12 is used as a diene in Diels-Alder cycloadditions, and its molecular structure is compared to that of the similar molecule 13, lacking the two exo methylene substitutents.
AB - Addition of carbon nucleophiles to (benzocyclobutenedione)tricarbonylchromiuni(0) (4) results in the formation of exo mono- and diadducts as well as 1,2-diketones as the consequence of proximal ring-opening reactions. In one case the unexpected formation of benzocycloheptenedione complexes is observed. Treatment of 4 with an excess of 1-ethoxy-1-lithioethene gives the product of a dianionic oxy-Cope rearrangement followed by an intramolecular aldol addition. This is also the case with lithiated methoxyallene, and as the result the first head-to-head coupling product 12 of two methoxyallene molecules is isolated in good yield. 12 is used as a diene in Diels-Alder cycloadditions, and its molecular structure is compared to that of the similar molecule 13, lacking the two exo methylene substitutents.
KW - Benzocyclobutene
KW - Benzocycloheptenedione
KW - Chromium
KW - Dianionic Oxy-Cope Rearrangement
KW - Methoxyallene
UR - http://www.scopus.com/inward/record.url?scp=0002597955&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1099-0690(199812)1998:12<2719::AID-EJOC2719>3.0.CO;2-H
DO - 10.1002/(SICI)1099-0690(199812)1998:12<2719::AID-EJOC2719>3.0.CO;2-H
M3 - Article
AN - SCOPUS:0002597955
SP - 2719
EP - 2727
JO - European Journal of Organic Chemistry
JF - European Journal of Organic Chemistry
SN - 1434-193X
IS - 12
ER -