ISSN:
0947-3440
Schlagwort(e):
Cinnamates
;
Spectroscopy
;
Photocycloaddition
;
Paracyclophanes
;
X-ray structures
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
In order to transfer the so-called topochemical control established by Schmidt and coworkers to fluid solutions, the [2.2]paracyclophane framework was substituted with two acryloyl substituents, one on each of the two decks. The 4 products thus formed are termed cinnamophanes. The pseudo-gem derivative, 1, was shown to undergo a very efficient stereospecific [2 + 2] photocycloaddition to form 5 with the highest quantum yield (0.8) ever observed for such a reaction. Whereas 2, 3 and 4, the regioisomers of 1, undergo a trans-cis photoisomerisation, compound 1 leads to the photocycloadduct as the sole photoproduct. This unusually fast cycloaddition reaction is not sensitive to oxygen and is largely unaffected by temperature variations. It is believed to be a singlet state reaction. The synthesis and a spectroscopic (absorption and fluorescence emission) study of 1-4 and 5 are described.
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jlac.1995199511274
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