Details
| Original language | English |
|---|---|
| Pages (from-to) | 253-265 |
| Number of pages | 13 |
| Journal | Liebigs Annalen |
| Volume | 1995 |
| Issue number | 2 |
| Publication status | Published - 27 Jan 1995 |
| Externally published | Yes |
Abstract
The syntheses of the tricarbonylchromium complexes 2 and 3 of 1‐oxobenzocyclobutene and 1‐hydroxybenzocyclobutene are described. Alcoholate 6 of 3 undergoes a ring opening to the corresponding ortho‐quinodimethane intermediate between −30 and −20°C, which is trapped by dienophiles with high diastereoselectivity. While with most dienophiles products with a 1,2‐cis configuration (7, 8, 10) are formed, vinyl sulfones react in an exo‐selective cycloaddition with formation of 1,2‐trans‐configurated cycloadducts (12, 13). The configuration of the cycloadduct with phenyl vinyl sulfone is confirmed by an X‐ray crystal structure analysis. As one of the important aspects of the chemistry of benzocyclobutene complexes is the chirality of compounds like 2 and 3, the enantiomeric resolution has been achieved via the semioxamazones of ketone 2.
Keywords
- Bicyclo[4.2.0]octa‐1,3,5‐triene, Chromium complexes, [4+2] Cycloadditions
ASJC Scopus subject areas
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In: Liebigs Annalen, Vol. 1995, No. 2, 27.01.1995, p. 253-265.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - η 6‐(1‐Oxobenzocyclobutene)tricarbonylchromium(0)
T2 - Preparation, Reduction, and Ring-Opening/Cycloaddition Chemistry of the 1-Hydroxybenzocyclobutene Complex
AU - Brands, Michael
AU - Wey, Hans G.
AU - Krömer, Rainer
AU - Krüger, Carl
AU - Butenschön, Holger
PY - 1995/1/27
Y1 - 1995/1/27
N2 - The syntheses of the tricarbonylchromium complexes 2 and 3 of 1‐oxobenzocyclobutene and 1‐hydroxybenzocyclobutene are described. Alcoholate 6 of 3 undergoes a ring opening to the corresponding ortho‐quinodimethane intermediate between −30 and −20°C, which is trapped by dienophiles with high diastereoselectivity. While with most dienophiles products with a 1,2‐cis configuration (7, 8, 10) are formed, vinyl sulfones react in an exo‐selective cycloaddition with formation of 1,2‐trans‐configurated cycloadducts (12, 13). The configuration of the cycloadduct with phenyl vinyl sulfone is confirmed by an X‐ray crystal structure analysis. As one of the important aspects of the chemistry of benzocyclobutene complexes is the chirality of compounds like 2 and 3, the enantiomeric resolution has been achieved via the semioxamazones of ketone 2.
AB - The syntheses of the tricarbonylchromium complexes 2 and 3 of 1‐oxobenzocyclobutene and 1‐hydroxybenzocyclobutene are described. Alcoholate 6 of 3 undergoes a ring opening to the corresponding ortho‐quinodimethane intermediate between −30 and −20°C, which is trapped by dienophiles with high diastereoselectivity. While with most dienophiles products with a 1,2‐cis configuration (7, 8, 10) are formed, vinyl sulfones react in an exo‐selective cycloaddition with formation of 1,2‐trans‐configurated cycloadducts (12, 13). The configuration of the cycloadduct with phenyl vinyl sulfone is confirmed by an X‐ray crystal structure analysis. As one of the important aspects of the chemistry of benzocyclobutene complexes is the chirality of compounds like 2 and 3, the enantiomeric resolution has been achieved via the semioxamazones of ketone 2.
KW - Bicyclo[4.2.0]octa‐1,3,5‐triene
KW - Chromium complexes
KW - [4+2] Cycloadditions
UR - http://www.scopus.com/inward/record.url?scp=84988072509&partnerID=8YFLogxK
U2 - 10.1002/jlac.199519950235
DO - 10.1002/jlac.199519950235
M3 - Article
AN - SCOPUS:84988072509
VL - 1995
SP - 253
EP - 265
JO - Liebigs Annalen
JF - Liebigs Annalen
SN - 0947-3440
IS - 2
ER -