Interconversion of nitrenes, azirenes, and diradicals: Rearrangement of 3-isoquinolylnitrene to o-cyanophenylketenimine and 1-cyanoisoindole

Vosswinkel, M., Luerssen, H., Kvaskoff, D. and Wentrup, Curt (2009) Interconversion of nitrenes, azirenes, and diradicals: Rearrangement of 3-isoquinolylnitrene to o-cyanophenylketenimine and 1-cyanoisoindole. Journal of Organic Chemistry, 74 3: 1171-1178. doi:10.1021/jo802273y


Author Vosswinkel, M.
Luerssen, H.
Kvaskoff, D.
Wentrup, Curt
Title Interconversion of nitrenes, azirenes, and diradicals: Rearrangement of 3-isoquinolylnitrene to o-cyanophenylketenimine and 1-cyanoisoindole
Formatted title
Interconversion of nitrenes, azirenes, and diradicals: Rearrangement of 3-isoquinolylnitrene to o-cyanophenylketenimine and 1-cyanoisoindole
Journal name Journal of Organic Chemistry   Check publisher's open access policy
ISSN 0022-3263
Publication date 2009-02-06
Year available 2008
Sub-type Article (original research)
DOI 10.1021/jo802273y
Volume 74
Issue 3
Start page 1171
End page 1178
Total pages 8
Place of publication Washington, D.C. U.S.A.
Publisher American Chemical Society
Language eng
Subject 0399 Other Chemical Sciences
C1
Abstract Photolysis of tetrazolo[1,5-b]isoquinoline/3-azidoisoquinoline 22T/22A generates 3-isoquinolylnitrene 23, which has been characterized together with a diradical species (25) by Ar matrix ESR spectroscopy. Photolysis at λ > 300 nm generates azirene 24, characterized by IR spectroscopy, whereas further broad-band UV photolysis destroys the azirene to produce o-cyanophenylketenimine 17. The use of 15N-labeled tetrazole/azide 22T′/22A′ demonstrates rapid equilibration of two regioisomeric 15N-labeled azirenes 24′ and 24′′ prior to formation of 17. Flash vacuum thermolysis (FVT) of 22T/22A affords 1-cyano-2H-isoindole 27 in quantitative yield. FVT of 15N-labeled tetrazole/azide 22T′/22A′ causes scrambling of 15N label in the 1-cyano-2H-isoindole product. It is concluded that the interconversion of azirenes 24 takes place via the unobserved diazacycloheptatetraene/diazacycloheptatrienylidene 32/33, and that the rearrangement of azirene to ketenimine 17 and 1-cyanoisoindole 27 takes place via reversion to nitrene 23 followed by ring opening to diradical 25.
Keyword Ring-expansion
Q-Index Code C1
Q-Index Status Provisional Code

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Chemistry and Molecular Biosciences
 
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Created: Thu, 03 Sep 2009, 08:49:47 EST by Mr Andrew Martlew on behalf of School of Chemistry & Molecular Biosciences