Asian Journal of Organic Chemistry最新文献

A hypervalent iodine-mediated one-step general method for the preparation of 2-amino-5-acyl-thiazoles and selenazoles has been disclosed. The reactions progress via umpolung cyclization of thio/seleno-urea with enaminones. Mechanistically, the reaction progresses via C─N bond cleavage of enaminones rather than C═C bond.

A highly efficient iridium-catalyzed ring-opening reactions of heterobicyclic alkenes with fluoroalkyl alcohols has been developed. The reaction utilizes readily available fluoroalkyl alcohols as fluoroalkoxylation reagents and exhibits a wide substrate scope, affording the fluoroalkoxylated products with trans-1,2-disubstituted dihydronaphthalene framework in good to excellent yields. Mechanistic insights, supported by computational studies, have been proposed to elucidate the reaction pathway.

A highly efficient electrochemical oxidative dehydrogenative N–N coupling of arylamines to selectively provide benzo[c]cinnolines and azoarenes has been investigated. In this simple process, various functional groups were tolerated under mild reaction conditions without additional metal or oxidant, and the practicality of the protocol was demonstrated by the preparation of benzo[c]cinnolines on a gram scale and later derivatization. Mechanism of studies shows that the reaction proceeds via a radical pathway with the hydrazine compound as an intermediate. Additionally, the base plays an important role in this transformation, potentially facilitating the dehydrogenation process.

A BF₃·Et₂O-promoted cascade annulation of 2-propynolphenols is described for the synthesis of 2-substituted 3-sulfenylbenzofurans. This protocol was achieved through a sequential Meyer–Schuster rearrangement/nucleophilic addition/intramolecular annulation sequence. Mechanistic studies and density functional theory (DFT) calculations provided robust support for the proposed reaction pathway and identified the combined process of the ring-closing step and the hydrogen transfer process as the rate-determining step. This method provides an efficient route to C─S bond formation for the assembly of a wide range of 3-sulfenylbenzofurans in excellent yields under mild conditions. The screening of these 3-sulfenylbenzofurans against four human cancer cell lines indicated their excellent anticancer activities, wherein compound 3y strongly inhibited prostate cancer cells, with a half-maximal inhibitory concentration value of 7.24 ± 0.45 µM.

A K₂S₂O₈‑mediated electrophilic selenocyclization of 1,7-dienes for the synthesis of selenium-containing benzoxepines is developed. This method features good regioselectivity, broad substrate scope, and good functional-group compatibility. Preliminary mechanistic studies reveal that this transformation may not undergo a free radical process.

Novel copper-catalyzed [4 + 1] annulation synthesizes spiro-cyclopentanes using bis-electrophilic Cu-aminoallyl cations (from EMCCs) and activated methylene dinucleophiles. The methodology exhibits broad substrate scope, accommodating EMCCs with electron-donating/withdrawing aryl groups /alkyl chains, and various activated methylene partners, providing a versatile alternative to construct spiro-cyclopentane via conventional [3 + 2] cycloadditions.

We developed a regioselective one-pot strategy for synthesizing highly substituted arylated 1H-indenes bearing heterocycles using BF₃·OEt₂-catalyzed multicomponent reactions. The proposed reaction mechanism includes BF₃ complex formation, tautomerization, nucleophilic aryl addition to arylalkyne, cyclization via a 4π-Nazarov-type intermediate, and deprotonation. The anticancer potential of the resulting compounds was evaluated using molecular docking studies that targeted the epidermal growth factor receptor (EGFR). All synthesized indene derivatives had high binding affinities, surpassing those of the reference drug erlotinib, indicating their potential as EGFR inhibitors. These findings suggest that, with further biological validation, the newly synthesized arylated indenes could serve as effective leads for the development of anticancer drugs.