Synthetic Communications最新文献

An efficient route for the chemoselective deoxygenation of benzylphenyl sulfones to the corresponding sulfides has been developed using a mixture of 1,2-bis(diphenylphosphino)ethane(dppe) and NBS as an effective promoter. This is the first development on the deoxygenation of diverse benzylphenyl sulfones under metal-free conditions. The mild reaction conditions, formation of the water soluble by-product and tolerance of a wide range of functional groups promote its broad applications in organic synthesis.

The carbazole-3-carbaldehyde 2, produced by N-ethyl carbazole via Vilsmeier-Haack reaction, was subjected to Dakin type oxidation with H₂O₂ and H₂SO₄ in methanol to produce the carbazole-3-ol 3. The reaction of 3 with a range of commercially available α-haloketones 4a–f in the presence of Al₂O₃ as catalyst in xylene led to their regio-selective cyclization to afford the furo[2,3-c]carbazoles 5a–f. Identification of the furo[2,3-c]carbazoles 5a–f were performed through ¹H NMR,¹³C NMR, FT-IR and high resolution mass spectrometry. Single crystal X-ray diffraction analysis was employed to further confirm the structures of the some of the targeted compounds. In vitro antidiabetic activities of the newly synthesized furocarbazoles 5a–e were investigated utilizing α-glucosidase and α-amylase enzymes. The biological evaluation revealed the obvious efficiencies of the targeted molecules toward the α-glucosidase enzyme inhibition with the potent IC₅₀ values compared to the standard acarbose. In the case of α-glucosidase inhibition, the furo[2,3-c]carbazoles chloro substituted 5c and nitro substituted 5f were found to be more potent than acarbose with the values of 215.0 and 162.70 μM, respectively. On the other hand, the compound 5f was found to be only promising candidate for α-amylase enzyme but not as effective as the standard acarbose.

Given the abundance of functional groups, meso- and macro-pores, and a high surface area, the piperazine-based poly(amic acid) was employed as a heterogeneous catalyst in the multicomponent reaction to prepare pyrrolidinone scaffolds in a green solvent, acting as a medium for mass transfer and crystallization solvent. The important parameters of the reaction were investigated to find the optimal reaction conditions. A conversion of 100% was obtained at reflux conditions within 30–100 min using a catalytic amount of 200 mg of piperazine-based poly(amic acid) per 2 mmol of reactants (100 mg of cat./1 mmol of reactant). The piperazine-based poly(amic acid) exhibited high recyclability and the recovered catalyst could be used in successive runs without worthy loss in its activity. This work revealed the catalytic activity of the piperazine-based poly(amic acid) as a promising functional polymeric heterogeneous catalyst for organic synthesis.

4-Hydroxy-7-methoxyquinolin-2-one (1) and its derivative 3-bromo-4-hydroxy-7-methoxyquinolin-2-one (2) serve as valuable intermediates for the synthesis of advanced hetero-compounds. The reactivity of compound (2) has been verified through multiple substitution reactions. Their reactions with 2-mercaptoacetic acid, 3-mercaptopropanoic acid, or 2-aminobenzoic acid resulted in the corresponding hetero-compounds with high yields. The synthesized compounds underwent thorough examination via elemental and spectral analyses. Additionally, DFT calculations confirmed their structures in accordance with spectral investigations. Furthermore, the study delved into the global chemical reactivity parameters.

Various indoles undergo Friedel–Crafts alkylation at the 3-position when treated with secondary arylmethyl acetates in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine. Tertiary benzylic alcohols are also effective alkylating agents, undergoing TMSOTf-promoted activation to yield alkylated indoles that feature quaternary centers. A related study shows that benzofuran reacts under similar conditions to yield 2-alkylated benzofurans when treated with similar alkylating agents, and the reaction has been extended to include other representative heteroarenes. Yields for these Friedel–Crafts alkylation products range from 43%–99% over a wide range of substrate combinations.

We report an efficient protocol for oxidation of primary/secondary benzyl alcohols and benzylamines to produce corresponding aldehydes or ketones. Our unified method involves the use of commercially available (diethylamino)sulfur trifluoride (DAST) as a reagent combined with DMSO as solvent and oxidant. The reaction provided corresponding carbonyl compounds in good to excellent yields with high purity and in short reaction times.

A series of novel quinoline-isoxazole hybrids 6a–o has been synthesized via multistep synthetic approach involving hetero Diels-alder reaction strategy. The target compounds were obtained in good yield, using low-cost readily available starting materials using simple reaction conditions. The newly synthesized compounds were confirmed using ¹H NMR,¹³C NMR, and Mass spectroscopic analysis techniques. Further, compounds 6a–o were subjected to in vitro antimicrobial screening against various bacterial and fungal strains, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Aspergillus niger, and Candida albicans. Among these, compounds 6i, 6j, and 6 l were found most active having equally potent compared to standard drug Ampicillin and Gentamycin. Moreover, in silico studies of 6a–o with E. coli DNA gyrase through molecular docking and MD simulations showed excellent binding properties of these derivatives with protein site.