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.

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In this work, a one-pot sequential organocatalytic method for the synthesis of fused [1,2,3]triazolo [1,5-a]quinolines through successive cyclization and condensation is presented. In this synthetic strategy, the intermolecular [3 + 2]-cycloaddition occurs between 1,3-dicarbonyl compounds and o-carbonyl-substituted phenylazide compounds, for the formation of the 1,2,3-triazole intermediates. Subsequently, an intramolecular condensation reaction generates the fused quinoline ring by the new CÀ C bond formation, giving the products in yields ranging from moderate to excellent. All the reactions were performed using 20 mol% of 1,8diazabicyclo[5.4.0]undec-7-ene (DBU) as catalyst in the presence of DMSO as solvent at 120°C for 24 h and tolerate a range of 1,3-dicarbonyl compounds, such as β-keto esters and 1,3-diketones, and o-formyl, o-acetyl or o-benzoyl substituted phenylazide compounds.

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Herein, we described a simple and efficient protocol for the synthesis of α‐hydroxyphosphonates containing 1,2,3‐triazole moiety in their structures under mild conditions. This approach was performed by Abramov reaction in a solvent‐free system, using Na2CO3 as catalyst at 70 °C, which provided the desired products from moderate to excellent yields. The substrate scope was effective for different organic functions, such as ester, ketone, and amide. The synthetic route is modulated by the presence of a bulky group at the hydrophosphoryl reagent, avoiding steric hindrance, since the Abramov reaction can be approached before the Click‐Chemistry protocol. The synthesis can also be carried out in a one‐pot method, minimizing costs, and without side reactions. Additionally, the chiral discrimination of the synthesized products was easily accessed by 1H and 31P nuclear magnetic resonance experiments, using a chiral solvating agent.

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