ISSN:
0009-2940
Keywords:
Azaazulenes
;
1,2,4,5-Tetrazine
;
[4 + 2] Cycloadditions, “inverse”
;
Azaazulene-quinoline rearrangement
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Azaazulenes as Dienophiles in the Diels-Alder Cycloaddition with 3,6-Bis(trifluoromethyl)1-1,2,4,5-tetrazineThe LUMO-diene-controlled [4 + 2] cycloaddition of the azaazulenes 6 and 17 with the tetrazine 1, one of the most reactive diazadienes “with inverse electron demand”, are described. Like azulene (2) the azaazulenes 6a, b react with 1 - probably by a two-step mechanism via the dipolar species 7 - to yield the adduct 8; N2 elimination leads to 9, which rearranges to the pyridazo[4,5-c]quinoline 13 and the azine-substituted 1-azaazulene 12. In a rather complex reaction sequence the 2-azaazulene 17 forms the salt 18; the crystal structure of 18 has been determined by X-ray diffraction methods.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19931260222
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