We describe here for the first time the synthesis of isochromenones fused to selenophenes. 5H‐Selenopheno[3,2‐c]isochromen‐5‐ones were obtained through a double intramolecular cyclization of methyl 2‐(organyl‐1,3‐diynyl)benzoate promoted by electrophilic species of selenium generated in situ by the reaction of dialkyl diselenides with Oxone®, using ethanol as solvent. The reactions were conducted satisfactorily under mild conditions, using a range of 1,3‐diynes and dialkyl diselenides as substrates. A total of sixteen unprecedent 5H‐selenopheno[3,2‐c]isochromen‐5‐ones were selectively obtained in moderate to good yields (40–86%) under reflux in an open flask and in short reaction times (1.0–2.5 h).magnified image

We report a protocol for the synthesis of 3-organyl-4-(organylchalcogenyl)­isoquinoline-2-oxides via electrophilic cyclization between alkynylbenzaldoximes and diorganyl dichalcogenides promoted by Oxone. A total of 21 3-organyl-4-(organylchalcogenyl)­isoquinoline-2-oxides were selectively obtained in yields of up 93% under an ultrasound irradiation condition in short reaction times (10–70 min). Additionally, the synthetic usefulness of the 3-phenyl-4-(phenylselanyl)­isoquinoline-2-oxide was demonstrated in the annulation reaction with 1-(2-bromophenyl)-3-phenylprop-2-yn-1-one and in the deoxygenation reaction with phenylboronic acid.

A new method was developed for the synthesis of 4-chalcogenyl-1H-isochromen-1-ones through the 6-endo-dig electrophilic cyclization of 2-alkynylaryl esters and diorganyl dichalcogenides under ultrasound irradiation. The reactions were performed under mild conditions, using Oxone as a green oxidant to promote the cleavage of the chalcogen–chalcogen bond in diorganyl diselenides and ditellurides to generate electrophilic species in situ. A total of 25 compounds were selectively obtained after 30–70 min, in good to excellent yields (74–95%). This procedure was extended to prepare 5H-selenopheno­[3,2-c]­isochromen-5-ones. Additionally, for the first time, the 4-chalcogenyl-1H-isochromen-1-ones were used as substrates in the thionation reaction, using Lawesson’s reagent and microwave irradiation under solvent-free conditions, obtaining the thio derivatives in yields of up to 99% in only 15 min.

We report herein an alternative method for the synthesis of seleno-dibenzocyclo­heptenones and seleno-spiro[5.5]­trienones through the radical cyclization of biaryl ynones in the presence of diorganyl diselenides, using Oxone as a green oxidizing agent. The reactions were conducted using acetonitrile as the solvent in a sealed tube at 100 °C. The protocol is operationally simple and scalable, exhibits high regioselectivity, and allows the synthesis of 24 dibenzocyclo­heptenones/spiro[5.5]­trienones in yields of up to 99%, 17 of which are unpublished compounds. Additionally, synthetic transformations of the prepared compounds, such as oxidation and reduction reactions, are demonstrated.

Oxone is a commercially available oxidant, composed of a mixture of three inorganic species, being the potassium peroxymonosulfate (KHSO5) the reactive one. Over the past few decades, this cheap and environmentally friendly oxidant has become a powerful tool in organic synthesis, being extensively employed to mediate the construction of a plethora of important compounds. This review summarizes the recent advances in the Oxone-mediated synthesis of N-, O- and chalcogen-containing heterocyclic compounds, through a wide diversity of reactions, starting from several kinds of substrate, highlighting the main synthetic differences, advantages, the scope and limitations.

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In the present study, the synthesis of new selenoethers from nucleophilic substitution reaction between organyl halides and nucleophilic species of selenium generated in situ was demonstrated. After, this method was applied for the synthesis of pyridylselenides glycerol derivatives 9b and 9c and the antinociceptive and anti-inflammatory effects, as well as, acute toxicity were evaluated. In the formalin test, the compound 9b caused a reduction in licking time in both phases. Compounds 9b and 9c increased the latency to response in the hot-plate test and reduced the licking time induced by glutamate. Our results revealed the involvement of the nitrergic and/or glutamatergic pathways in the antinociceptive action of the compounds. Additionally, 9b and 9c did not cause any toxicity signals and oxidative stress parameters were not modified by treatments. Here, it was developed an alternative and efficient method for the synthesis of selenoethers glycerol derivatives. Furthermore, we demonstrated that this class is indeed interesting for the research of new drugs. Graphical Abstract ᅟ.

The present study reports a simple two‐step method for the synthesis of arylselanyl hydrazide derivatives using hypophosphorous acid and polyethylene glycol (H3PO2/PEG‐400) as an alternative reducing system and hydrazine hydrate (NH2NH2⋅xH2O/50–60 %). This single‐vessel procedure was employed with methyl acrylate 2a and methyl bromoacetate 2b using diaryl diselenides to generate the nucleophile species to produce, respectively, 3‐(arylselanyl)propane‐hydrazides 4a–e and 2‐(arylselanyl)acetohydrazides 5a–e with good yields by accelerating the reduction of −Se−Se− bond, when compared to available methods. The synthesized molecules are structurally similar to the isoniazid (INH). Therefore, we perform in silico molecular docking studies, using the lactoperoxidase enzyme, in order to verify whether the INH Se derivatives could interact in a similar way to INH at the active site of the mammalian enzyme. The in silico results indicated a similar type of interaction of the arylselanyl hydrazide derivatives with that of INH. In view of the similar in silico interaction of the selenium derivatives of INH, the arylselanyl hydrazide derivatives reported here should be tested against Mycobacterium tuberculosis in vitro.