Issue Information
Journal of Heterocyclic Chemistry, Volume 61, Issue 3, Page 397-400, March 2024.
Monthly Archives: March 2024
Amine and nitramine functionalization of imidazole‐triazine and triazole‐triazine skeletons: Exploring for potential multipurpose energetic materials
A set of novel energetic materials (2–7) were designed, synthesized, and thoroughly analyzed, featuring five and six-membered C-C bonded structures that incorporate imidazole-triazine and triazole-triazine frameworks, which displayed balanced energetic properties, stability, and sensitivity.
Abstract
A series of five and six-membered C-C bonded energetic materials (2–7) based on a combination of imidazole-triazine and triazole-triazine backbones were designed, synthesized, and characterized using NMR, IR, Mass spectrometry, and TGA-DSC studies. Further, the structure of compound 4 was supported by single-crystal X-ray analysis. All the newly synthesized energetic compounds exhibit good density, excellent thermal stability, good detonation performance, and low mechanical sensitivity toward impact and friction. Among all, the nitrate salt 4 exhibits balanced properties, including high density (1.80 g cm−3), excellent thermal stability (254°C), good detonation velocity (8178 m s−1), and low sensitivity towards impact and friction. The facile synthetic feasibility, thermal stability, energetic performance, and insensitivity of all the molecules suggest they can be used as an insensitive secondary explosive in various defense and civilian applications.
One‐pot green synthesis, study of fluorescence properties, and biological activity of pyrano[3,2‐c]chromenes derivatives via mesoporous materials MgO/SBA‐15
![One-pot green synthesis, study of fluorescence properties, and biological activity of pyrano[3,2-c]chromenes derivatives via mesoporous materials MgO/SBA-15](https://onlinelibrary.wiley.com/cms/asset/5010ae52-7be4-4a68-a94c-9089dc0d2416/jhet4772-toc-0001-m.png)
One-pot green synthesis, study of fluorescence properties, and biological activity of pyrano[3,2-c]chromenes derivatives via mesoporous materials MgO/SBA-15.
Abstract
This current work describes the preparation of MgO-SBA-15 catalysts by ultrasonic method, and it is characterized by the different analysis techniques of XRD, BET, SEM, and IRTF. In order to find out an application for this mesoporous material, MgO/SBA-15 was used as a heterogeneous catalyst in the one-pot synthesis of pyrano[3,2-c]chromenes derivatives isolated at room temperature reaction according to green chemistry criteria. To enhance these derivatives, a spectroscopic study of molecular fluorescence properties was carried out as well as an identification analysis by nuclear magnetic resonance and FTIR was used. Furthermore, biological activity experiment is also carried out, from where the obtained test results were satisfactory for AC09, AC05, and AC10 compounds and they are checked after computation by molecular modeling.
Dearomative [4 + 2] cycloaddition of 3‐nitroindoles with ortho‐amino Morita−Baylis−Hillman carbonates to forge indole‐fused quinolines
![Dearomative [4 + 2] cycloaddition of 3-nitroindoles with ortho-amino Morita−Baylis−Hillman carbonates to forge indole-fused quinolines](https://onlinelibrary.wiley.com/cms/asset/4d50e124-f82c-4a74-aa1e-9a3e828bf3c2/jhet4781-toc-0001-m.png)
A dearomative [4 + 2] cycloaddition of 3-nitroindoles ortho-amino Morita−Baylis−Hillman carbonates was established under mild conditions.
Abstract
A dearomative [4 + 2] cycloaddition of 3-nitroindoles ortho-amino Morita−Baylis−Hillman carbonates was established under mild conditions. This method provides an efficient and practical approach for delivering tetrahydro-5H-indolo[2,3-b]quinolines containing three contiguous stereocenters, two tertiary and one quaternary, in high yield (up to 95%) with excellent diastereoselectivity (all cases >25:1 dr). The potential synthetic applications of this strategy were also highlighted by the scale-up experiment and further synthetic transformation. Moreover, the structure and relative configuration of the cycloadduct was unequivocally confirmed by single-crystal X-ray diffraction.
Visible light‐mediated photocatalyzed synthesis of oxazole via intermolecular CN and CO bond formation
Eosin Y-catalyzed synthesis of oxazole via intermolecular CN and CO bond formation.
Abstract
An efficient visible light-mediated, eosin Y-catalyzed synthesis of oxazole has been developed from benzil with primary amines, that providing a straightforward, green, and environmentally benign access to a wide variety of substituted oxazole-2-amines under mild reaction conditions.
Role of aurone ligands in microwave enhanced Mn (II) and Co (II) catalyzed dehydrogenative coupling reaction: An efficient ligand for the synthesis of quinoline, pyridine, and pyrrole
An efficient method for the synthesis Quinoline, Pyridine and pyrrole has been achieved by a new catalytic synstem. The control experiments suggested these reactions were performed through Dehydrogenation reaction.
Abstract
The role of new series of phosphine-free aurone ligands have been investigated in microwave-enhanced Mn (II) and Co (II) dehydrogenative coupling reactions. Various heterocyclic compounds such as Quinoline, pyridine, and pyrrole have been synthesized and characterized by NMR spectroscopy. The synthesized ligands (L1–L4) with Mn(II) and Co (II) salt showed excellent catalytic activity and proved to be very effective for the dehydrogenative coupling reaction. This synthetic method involves the in-situ formation of a metal ligand complex that was analyzed by mass spectrometry. A broad range of substrates including aliphatic ketone, heterocycles, and sterically hindered Ketone coupling partners are well tolerated in the developed protocol.
Catalyst‐free one‐pot synthesis of 2,4,5‐tri‐ and 1,2,4,5‐tetrasubstituted imidazoles
The present work emphasizes catalyst-free imidazole synthesis using diversified aldehydes, benzil, ammonium acetate, or amines. Ammonium acetate as a reactant catalyst by dissociating into acetic acid for formation to ascertain the imidazoles. The advantages are efficient, greener, and with moderate to excellent yield in shorter reaction time in ethanol:water, a greener solvent.
Abstract
The present work emphasizes catalyst-free 2,4,5-tri- and 1,2,4,5-tetra substituted imidazole synthesis using diversified aldehydes with benzil, ammonium acetate, or amines. Ammonium acetate plays a vital role as a reactant catalyst by dissociating into acetic acid to afford imine and diamine formation to ascertain the 2,4,5-tri- and 1,2,4,5-tetra substituted imidazoles. The key advantages of the current approach are efficient, greener, eco-friendly, and facile, with moderate to excellent yield in shorter reaction time at the temperature of 80°C. Ethanol:water as a solvent makes the reaction process eco-friendly. Overall, the described approach offers a promising route for the efficient and sustainable synthesis of substituted imidazoles, which have a wide range of applications in various fields, including pharmaceuticals, agrochemicals, and materials science.
Sc(OTf)3‐catalyzed tandem (3+3)‐annulation/lactonization of cyclopropanes with salicylaldehyde nitrones to access polycyclic 1,2‐oxazines
Sc(OTf)3-catalyzed tandem (3+3)-annulation/lactonization of cyclopropanes with salicylaldehyde nitrones to access polycyclic 1,2-oxazines with excellent diasteroselectivies.
Abstract
A Sc(OTf)3-catalyzed tandem (3 + 3)-annulation/lactonization of donor-acceptor cyclopropane 1,1-dieters with salicylaldehyde nitrones has been reported, affording a wide range of tetrahydrochromeno[4,3-c][1,2]oxazin-5(1H)-ones in moderate yields with excellent diastereoselectivities. Besides, the gram-scale reaction has also been explored to demonstrate the utility of this protocol. Moreover, the mechanism was investigated through control experiments, which show the reaction proceeds via a tandem (3 + 3)-annulation/lactonization reaction.
Cu‐catalyzed dehydrogenative CO arylation for the synthesis of 6‐methyl benzofuro[3,2‐c] quinoline derivatives
![Cu-catalyzed dehydrogenative C<span class='icomoon'></span>O arylation for the synthesis of 6-methyl benzofuro[3,2-c] quinoline derivatives](https://onlinelibrary.wiley.com/cms/asset/fd580e7a-1d1f-4d1f-a1ec-7373199ea950/jhet4774-toc-0001-m.png)
Copper catalyzed dehydrogenative C—O arylation
Abstract
A novel strategy for the synthesis of 6-methyl benzofuro[3,2-c] quinoline derivatives via copper-catalyzed dehydrogenative CO arylation has been presented. Optimization studies have been carried out by varying various catalysts, bases, solvents, and other physical parameters. Keeping use of this dehydrogenative cross-coupling CO arylation reaction, a variety of bioactive building blocks like fused benzofuro quinoline heterocycles were smoothly assembled in moderate to higher yields.
Design, enantioselective synthesis, and antiviral activities against potato virus Y of axially chiral thiazine derivatives
A series of novel thiazine derivatives featuring axial chirality in both (R) and (S) configurations were successfully synthesized by N-heterocyclic carbene-catalyzed enantioselective [3 + 3] annulations, and their potential as anti-plant virus agents against potato virus Y was evaluated.
Abstract
A series of novel thiazine derivatives featuring axial chirality in both (R) and (S) configurations were successfully synthesized by N-heterocyclic carbene (NHC)-catalyzed enantioselective [3 + 3] annulations, and their potential as anti-plant virus agents against potato virus Y (PVY) was evaluated. Biological activity results demonstrated that most of these chiral thiazine derivatives exhibited significant activities against PVY. Notably, compound (S)-3g displayed a remarkable 58% inactivation effect against PVY at a concentration of 500 μg/mL, slightly surpassing the effectiveness of Ningnanmycin (NNM) at 57%. Additionally, (S)-3g exhibited curative activity of 57%, which is superior to NNM (53%). Molecular docking studies revealed preliminary insights into the distinct biological properties of the two different enantiomers, (R) or (S)-3g against PVY, wherein single enantiomer (S)-3g formed a more stable interaction with PVY-CP, as indicated by its lower binding free energy (−41.18 kcal/mol) compared to (R)-3g (−36.9 kcal/mol). The findings in this study with a new class of axially chiral thiazine derivatives shall inspire further development of chiral heterocycles as potential drug candidates for the protection of plant virus infections.