The first example of an unusual addition of chromone‐substituted acrylic acid to enamines is described. The process shows high versatility concerning both enamines and chromones. The reaction is catalyzed by tertiary amines and is highly likely of Morita–Baylis–Hillman‐type. The described compounds show combined moderate inhibitory action on BChE and antagonism towards NMDA receptors which makes them a perspective group for the development of anti‐Alzheimer drugs.

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We report a flexible approach to the synthesis of phenanthrene-like heterocycles through organocatalytic AN-RORC (Addition of the Nucleophile, Ring Opening, and Ring Closure) reaction of electron-deficient 3-vinylchromones with cyanoacetamide. Addition of highly basic DBU (1,8-diazabicyclo [5.4.0]undec-7-ene) or tetramethylguanidine (TMG) at 80°C leads to chromeno [4,3-b]pyridines in good yields, whereas Et 3 N at 20°C made it possible to obtain the less accessible pyrano [3,2-c]chromenes and their 2-imines. The synthesis proceeds in mild conditions (EtOH, 20-80°C), is versatile and applicable for a wide scope of reactants. The obtained compounds show bright fluorescence in the range 460-595 nm with high quantum yields (up to 0.84) in various solvents (MeCN, DMSO, EtOH, H 2 O).

We report an easy and powerful approach to the synthesis of novel chromeno[4,3-d]pyrimidine-5-acetic acids through ANRORC reaction of electron-deficient 3-vinylchromones and 1,3-N,N-binucleophiles. The reaction proceeds under mild conditions (EtOH, rt) and is applicable to a wide range of substrates. The described compounds show fluorescence in the violet-blue range (390–460 nm) with Stokes shift of 40–80 nm and moderate quantum yield (0.15–0.20). As the electron-withdrawing group is conserved in the form of an acetic acid fragment, these compounds may readily be functionalized or conjugated to a required substrate for (bio)analytical purposes.

The [4+2] cycloaddition of chromone‐fused dienes with enamines was found to be an efficient method for the synthesis of 4,4a‐ and 3,4‐dihydroxanthone derivatives. Either product type could be obtained by choosing the proper conditions [reaction time and addition of La(NO3)3 as a Lewis acid]. Calculations using density functional theory and Møller–Plesset perturbation theory showed that the isomerization of 4,4a‐dihydroxanthones to 3,4‐dihydroxanthones occurred through a base‐assisted sigmatropic rearrangement. The described reaction provides a convenient route to a natural‐product‐inspired group of 4,4a‐dihydroxanthones with cytotoxic activity.