Chromones as a privileged scaffold in drug discovery: A review

Hydrazone Derivatives Enhance Antileishmanial Activity of Thiochroman-4-ones

“…Structures of thiochroman-4-ones ( [1][2][3][4][5] and hydrazone derivatives (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). …”

“…In our search for new chemotherapeutic alternatives to fight leishmaniasis we have explored thiochroman compounds, which could be considered a potential privileged scaffold [5,6] because of its great similarity with the chroman compounds which display a broad range of bioactivities [7]. In addition, numerous hydrazones have been reported to possess interesting biological activities such as antitumoral, antiviral and antiparasitic effects [8][9][10]; some hydrazones also exhibit activity against the parasites that cause malaria, leishmaniasis and Chagas disease [3,[11][12][13][14][15][16][17][18], where the inhibition of proteases and represent the most common mechanism of action for the hydrazones [16,[19][20][21].…”

An Overview of 2‐Styrylchromones: Natural Occurrence, Synthesis, Reactivity and Biological Properties

“…[70,74] A large variety of 2,3-diarylxanthones 103 result as major products from reactions between polysubstituted 3-bromo-2-styrylchromones and styrenes, mediated by palladium catalysts, in one-pot fashion. The proposed mechanism involves Heck coupling between brominated chromones and styrenes to form 2,3-distyrylchromones, in situ electrocyclization, [1,5]-sigmatropic hydrogen migration to give 3,4-dihydroxanthones and finally oxidation to achieve the corresponding 2,3-diarylxanthones 103. From this reaction it was also possible to isolate 2,3-diaryl-3,4-dihydroxanthone intermediates 104 and 6,7-diaryl-1-hydroxy-9H-xanthen-9-ones 105 when 3-bromo-5-methoxy-2-styrylchromones were used as brominated derivatives (Scheme 26).…”

“…However, studies conducted by Letcher and Yue in 1992 on the reactivity of 2-SCs with maleic anhydride and with N-phenylmaleimide and extensive spectroscopic characterization established that the adduct structures were those of the isomeric 1,2,3,4-tetrahydro-9H-xanthen-9-ones 57 (Scheme 15). [95,96] The formation of these compounds 57 was the result of a [1,3] proton shift in the formed adducts 56, with the driving force of this isomerization being the stability of the reformed chromone moiety.…”

“…the A component in structure 1, Figure 1), a well-known class of oxygenated heterocyclic compounds, play an important role in nature due to their recognized biological, pharmacological and biocidal activities. [1][2][3] These effects of these naturally occurring compounds, associated with the large variety of substituents and positions in their skeleton, have resulted in strong demand over the years for their isolation in large amounts, for the development of efficient and eco-friendly routes for their synthesis, as cyclic systems and important intermediates in the search for bioactive compounds. It is our intention in this review to give a general overview on the natural occurrence, synthesis, reactivity and biological properties of 2-styrylchromones, which were published up until 2016.…”