Beilstein J. Org. Chem.2022,18, 1088–1099, doi:10.3762/bjoc.18.111
investigated and the denitrogenativeannulation towards imidazoloquinoxalines could be observed as a competing reaction depending on the alkyne concentration and the substitutions at the quinoxaline.
Keywords: click reaction; CuAAC; denitrogenativeannulation; imidazole; metal complexes; quinoxaline
imidazole-fused products via denitrogenativeannulation leading to 2 is, compared to the ever-present CuAAC, less known and was only shown with one example so far [11].
The study described herein intends to investigate the reactivity of tetrazolo[1,5-a]quinoxalines 1 concerning the competing formation of
reactions and denitrogenativeannulation according to Roy et al. [11]. Copper-catalyzed azide–alkyne cycloadditions are initiated via the (dual) complexation of the alkyne, whereas denitrogenativeannulation on 1,2,3,4-tetrazoles is assumed to start via complexation of the open-form azide 18 (see Scheme 4
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Graphical Abstract
Scheme 1:
Reactions of tetrazoloquinoxalines 1 to 1,2,3-triazoloquinoxalines 3 via CuAAC and denitrogenative ...