| Title: |
7-(dimethylamino)tricyclo[5.2.2.0(1,6)]undecene derivatives from beta-cyclohexenyl beta-dimethylamino-substituted alpha,beta-unsaturated Fischer carbenes |
| Authors: |
Wu, Y.; Labahn, T.; Demeter, A.; Zachariasse, Klaas A.; de Meijere, Armin |
| Contributors: |
Wu, Y.; Labahn, T.; Demeter, A.; Zachariasse, Klaas A.; de Meijere, Armin |
| Publisher Information: |
Wiley-v C H Verlag Gmbh |
| Publication Year: |
2004 |
| Collection: |
Georg-August-Universität Göttingen: GoeScholar |
| Description: |
When heated in pyridine at 80 C, pentacarbonyl[(2E)-3-cyclohexenyl-3-(dimethylamino)-1-ethoxy-2-propen-1-yl- idene]chromium (1-Cr) and -tungsten (1-W) complexes undergo 6pi-electrocyclization and subsequent reductive elimination to yield the cyclohexane-annelated cyclopentadiene 6, which equilibrates by 1,5-hydrogen shift with its more reactive isomer 7. The latter molecule is efficiently trapped in Diets-Alder reactions with various alkynes 2 and styrenes 8 to give the cyclohexane-annelated norbornadiene 3 and norbornene derivatives respectively, with high regio- and diastereoselectivity in 15-91% yields. The enol ether moiety in compound 3 is particularly easily hydrolyzed, probably due to the through-space interaction between the two double bond moieties, so that the norbornenone derivatives 4 are isolated in all but one case after chromatographic purification. In this reaction, the tungsten complex 1-W consistently gave lower yields than 1-Cr. Arylalkynes with strongly electron-withdrawing groups and minimal steric congestion are particularly suitable reaction partners for 7. The formation of bis-cycloadducts 10 from suitable diynes largely depends upon the steric and electronic properties of the corresponding alkynyl-substituted mono-cycloaddition products of type 4 or 11. With the fluorenyl-substituted tricycle 4w in acetonitrile at 25 degreesC, but not with 4y, dual fluorescence is observed, with a red-shifted unstructured additional emission band with a dipole moment of 32 D, originating from intramolecular charge transfer. The molecule 2y has an exceptionally large radiative rate constant of 13 x 10(8) s(-1). ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004). |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| Relation: |
000225273100022 |
| DOI: |
10.1002/ejoc.200400471 |
| Availability: |
https://resolver.sub.uni-goettingen.de/purl?gro-2/47334; https://doi.org/10.1002/ejoc.200400471 |
| Rights: |
info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.78DA42AA |
| Database: |
BASE |