Beilstein J. Org. Chem.2019,15, 2684–2703, doi:10.3762/bjoc.15.262
Strukturchemie, Universitätsstraße 1, D-40225 Düsseldorf, Germany 10.3762/bjoc.15.262 Abstract Starting from substituted alkynones, α-pyrones and/or 1H-pyridines were generated in a Michael addition–cyclocondensation with ethyl cyanoacetate. The peculiar product formation depends on the reaction conditions as
well as on the electronic substitution pattern of the alkynone. While electron-donating groups furnish α-pyrones as main products, electron-withdrawing groups predominantly give the corresponding 1H-pyridines. Both heterocycle classes fluoresce in solution and in the solid state. In particular
emission solvatochromism. Also a donor-substituted α-pyrone shows pronounced aggregation-induced emission enhancement.
Keywords: cyclocondensation; DFT calculations; fluorescence; heterocycles; 1H-pyridines; α-pyrones; Introduction
A high sensitivity and precise tuneability of fluorescence colors are
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Graphical Abstract
Scheme 1:
Consecutive three-component alkynylation–Michael addition–cyclocondensation (AMAC) synthesis of α-p...