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This article presents a catalytic approach for site‐selective α‐C−H functionalization of N‐benzyl tetrahydroisoquinolines, which are important tertiary amine derivatives. Using iron salt as a catalyst, we have selectively functionalized carbon‐hydrogen bonds of tertiary amine molecules with diverse moieties, such as imidazopyridine, indoles, and phenylacetylenes. The method offers a broad substrate scope and excellent functional group tolerance, making it a valuable tool for the synthesis of complex molecules. A mechanism is also proposed based on control experiments, which explains the probable reason for selectivity. This iron‐catalyzed C−H functionalization represents a significant advancement in the field of organic synthesis, showcasing the potential of iron catalysis for the construction of valuable chemical motifs. [ABSTRACT FROM AUTHOR]

We have synthesized copper-incorporated KIT-5 mesoporous materials which were characterized thoroughly by powder XRD, N2-sorption, UV-Vis, HR-SEM & EDS and HR-TEM techniques. The low angle PXRD with theta values of 0.609, 0.660, 0.704 and 0.746 confirmed the mesoporosity of the synthesized materials. In addition, the materials showed type-IV isotherms which are spherical in morphology and fringes with pores of materials supporting the formation of mesoporous materials. The catalytic activity of synthesized materials was also investigated. We have used our materials as catalyst for the synthesis of 1,2,3-triazole derivatives via three component reaction of alkyl/aryl halide, terminal alkynes and sodium azide in water as a solvent. The desired triazole products were obtained in very good yields. This study indicates the importance of Cu element, solid support with uniformity of metal nanoparticles over the materials. The recyclability study with PXRD data of the catalyst confirmed the existence of the mesoporosity of the catalyst after the reaction and the yield decreased marginally from 98 to 91% over three cycles. This reaction has broad substrate scope and is compatible for aliphatic, aromatic, allyl substrates giving high yield of triazole products. [ABSTRACT FROM AUTHOR]

A catalyst‐free approach for the synthesis of oxazolidine derivatives is developed here. Though the synthesized oxazolidines contain three stereogenic centers, single diastereomer of the product is obtained. Single crystal X‐ray analysis of the product confirmed the stereochemistry. The reaction is performed by taking tetrahydroisoquinoline/cyclic benzylic amine (1 equivalent) and aromatic aldehyde (2 equivalent) in water under refluxing condition which produces excellent yield (87–96 %). With pyrrolidine as amine substrate, the reaction gives α,β‐unsaturated cyclic imines which is an example of β‐C−H functionalization of secondary amine. The proposed mechanism shows that the reaction proceeds through the formation of azomethine ylide which undergoes [3+2]‐cycloaddition reaction providing the oxazolidine product. [ABSTRACT FROM AUTHOR]

In this study, active compound loaded stable nanoemulsion (surface charge -18 mV) was developed having small diameter (<100 nm) from the plant extract of raw Syzygium aromaticum, Ocimum tenuiflorum and rhizome of Zingiber officinale. The antimicrobial and antioxidant properties of formulated nanoemulsion were analyzed. The nanoemulsion showed good antimicrobial activity against various food poisoning organisms viz. bacteria (Staphylococcus aureus and Escherichia coli) and fungi (Candida albicans). For the antioxidant study, two different methods 2,2-diphenyl-1- picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic 167 acid) diammonium salt (ABTS) were used, and a satisfactory result achieved (% inhibition for DPPH: 63.64±1.85 and ABTS: 48.36±1.12). The nanoemulsion in combination with a low dose of benzoic acid (200 ppm) is used as a preservative in formulated apple juice. The formulated juice quality was analyzed compared with standard fruit juice during a storage period of 30 days and quality of fruit juice remained good. This method thus allows reducing the use of synthetic preservatives with added benefit of natural beneficial compound in the formulated juice for human consumption. [ABSTRACT FROM AUTHOR]

We have developed an efficient iodine-catalyzed route for the synthesis of 2-(alkylthio)-substituted 1,4-enedione derivatives from styrenes under an open air atmosphere. Styrenes are heated with a range of sulfoxides in the presence of iodine and potassium persulfate to afford the desired products in high yields. Except for DMSO, all the sulfoxides are synthesized in the laboratory and are used crude. The products are formed as mixtures of E and Z stereoisomers that are easily separable by column chromatography. Both oxygen atoms of 1,4-enedione product originate from aerial oxygen. A mechanism is proposed based on control experiments and literature reports. [ABSTRACT FROM AUTHOR]

Three polycyclic chromeno[2,3-b]indolecontaining indole and naphthalene rings fused by a pyran ring were synthesized by metal-free C–H functionalization method and their photophysical studies were done. Steady state absorption spectra do not show solvent effect while fluorescence spectra exhibit solvatochromic shift. The molecules exhibit ultra-high Stokes shift of the order of 3.07 eV (24,696 cm−1) in acetonitrile and 2.12 eV (17,054 cm−1) in ethyl acetate. To corroborate experimental observation, we performed computational investigation both in gas and solvent phases. The computed results are in good agreement with the experimental observation. Analysis of the frontier molecular orbitals as well as natural transition orbitals depicts intramolecular charge transfer in the molecules. Further, gas phase as well as solvent phases optimized structures in the ground and excited states of all chosen molecules show increase in planarity in the excited state. An excited state intramolecular charge transfer accompanied by structural relaxation leading to planarity in the excited state has been suggested to cause large Stokes shifted fluorescence emission in these molecules. [ABSTRACT FROM AUTHOR]