Intra-intermolecular criss-cross cycloaddition of nonsymmetrical allenylazines with fluorinated enone as an initial step in the synthesis of 4H-pyrrolo[1,2-b]pyrazoles
Authors | |
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Year of publication | 2006 |
Type | Article in Periodical |
Magazine / Source | European Journal of Organic Chemistry |
MU Faculty or unit | |
Citation | |
Field | Organic chemistry |
Keywords | criss-cross; cycloaddition; 1-3-dipoles; nonsymmetrical azines; allenes; |
Description | Nonsymmetrical allenylazines undergo in boiling xylene intramolecular cycloaddition via formation of an unstable 1,3-dipole, which reacts with an added dipolarophile. In this paper we pay attention to the first intra-intermolecular criss-cross cycloaddition with a fluorinated enone. Although the expected products with three fused heterocycles were not isolated, new bicyclic products were found and characterized. These compounds are formed by a spontaneous transformation connected with fluorine atom migration and hydrogen fluoride elimination. A mechanism of the reaction is discussed to explain the formation of these new heterocycles. |
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