ISSN:
0947-3440
Keywords:
1-Oxa-3-azahexatrienes
;
1-Oxa-3-azoniahexatriene Salts
;
Protonation
;
Calculations, ab initio
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Differently substituted 1-oxa-3-azahexatrienes 3 were synthesized either by acylation of N-silyl-1-azabutadienes 1 or by a four-step-one-pot procedure starting from the nitriles 5, involving a Wittig-Horner-Emmons-type olefination as the key step. Both methods allow the isolation of the highly reactive compounds 3. The configuration and conformation of 31 in the crystalline state by X-ray diffraction were determined, indicating an (E) configuration of the C=C bond and a gauche conformation of the C=N—C=O subunit. The reactivity of compounds 3 towards tetrafluoroboric acid was studied. Protonation takes place exclusively at the nitrogen atom leading to the 1-oxa-3-azoniahexatriene salts 10. Quantum-chemical ab initio model calculations for all possible structures of the parent substances C4H5NO 9 and C4H6NO+ 14-16 were performed in order to obtain quantitative data regarding the structural and dynamic behavior of these highly flexible molecules in the gas phase.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.1995199506144
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