Beilstein J. Org. Chem.2014,10, 784–793, doi:10.3762/bjoc.10.74
compounds, with a new heterocyclic skeleton, are the result of the coupling of two molecules of azirine and two molecules of acylketene and can be prepared only from 3-aryl-2H-azirines having no electron-withdrawing groups in the aryl substituent. Calculations at the DFT B3LYP/6-31G(d) level for the various
: acylketene; azirine; domino reaction; furandione; Introduction
2H-Azirines, the most strained nitrogen unsaturated heterocyclic systems, are versatile building blocks for the construction of various heterocyclic nitrogen-containing compounds. Because 2H-azirines contain an activated C=N double bond and a
was confirmed by X-ray analysis (Figure 5). In the case of the reaction of the azirine 2d “dimeric” products of type 3, 4 and 5 were not detected, most probably due to steric hindrance both for the reaction of monoadduct 17 with acylketene 3a and the “dimerization” of 2d to tetraphenyldihydropyrazole
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Graphical Abstract
Scheme 1:
Reactions of furan-2,3-diones 1 and azirines 2.