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In this review, we have summarised the significant advances made in triazine-based COP synthetic strategies and their catalytic advancements. Synthetic methodologies are discussed in a simplistic way to create a better understanding for future modification of these methods.

Simple ammonium ionic liquids [ILs] are efficient, green, environmentally friendly catalysts in promoting the Biginelli condensation reaction, Hantzsch reaction and Niementowski reaction to afford 1,2,3,4-tetrahydropyrimidine, 2-aminothiazole and quinazolinone derivatives respectively by eliminating the need for harmful volatile organic solvents. These [ILs] are air and water stable, easy to prepare and cost-effective. The effects of the anions and cations present in [IL] on reactions were investigated. The results clearly indicated that the Biginelli condensation reaction, Hantzsch reaction and Niementowski reaction were heavily influenced by the acidity of [IL], and among various ammonium ionic liquids, [Et3NH][HSO4] showed the best catalytic activity. Furthermore, [IL] could be easily separated and reused with a slight loss of its activity. This technique provided a good alternative way for the industrial synthesis of 1,2,3,4-tetrahydropyrimidinones, 2-aminothiazoles and quinazolinones. The present processes are eco-friendly methods for the synthesis of these derivatives authenticated by several green parameters, namely, E-factor, process mass intensity, reaction mass efficiency, atom economy, and carbon efficiency.

The artemisinin resistance has posed a serious threat against malaria elimination lately. Past few years have seen important development of several peroxide based medicinal compounds and their derivatives such as trioxanes and tetraoxanes. Here, we report a rapid, one-pot method for synthesizing a new series of N-sulfonylpiperidine dispiro-1,2,4,5-tetraoxane analogs with diverse substitution on the tetraoxane ring i.e., various substituted alkyl and aryl sulfonyl chlorides, as well as cyclic, acyclic and aryl substituted ketones. All the synthesized tetraoxanes were characterized by spectroscopic (

Synthesis of thienoindoles via easy and atom economical approaches followed by their potent applications.

Sulfonic acid functionalized over biguanidine fabricated silica-coated heterogeneous magnetic nanoparticles (NP@SO3H) have been synthesized, well characterized and explored for the first time, as an efficient and recyclable catalyst for N-formylation of primary amines under mild reaction conditions. Exploiting the magnetic nature of Fe3O4, the prepared catalyst was readily recovered from the reaction mixture via an external magnet. The catalyst can be reused for up to six cycles without any substantial loss of catalytic activity. The cost effectiveness, simple methodology, wide substrate tolerance, excellent yield and easy work-up are the additional advantages of present catalytic system.

Sulfonic acid functionalized over biguanidine fabricated silica-coated heterogeneous magnetic nanoparticles (NP@SO

Mechanistic insights into the interaction of five previously chemically synthesized triazole-linked chalcone analogs (CTs) with human serum albumin (HSA) were sought using various spectroscopic techniques (UV-visible absorption, fluorescence, and circular dichroism) and molecular docking. The fluorescence quenching experiments performed at three different temperatures (288, 298 and 308 K) revealed the static mode of quenching and the binding constants (Kb ∼ 106–9) obtained indicated the strong affinity of these analogs for HSA. Furthermore, significant changes in the secondary structure of HSA in the presence of these analogs were also confirmed by far UV-CD spectroscopy. The thermodynamic properties such as the enthalpy change (ΔH°), Gibbs free energy change (ΔG°) and entropy change (ΔS°) revealed that the binding process was spontaneous and exothermic. Theoretical studies, viz., DFT and molecular docking corroborated the experimental results as these five analogs could bind with HSA through hydrogen bonding and hydrophobic interactions. The present study provides useful information regarding the interaction mechanism of these analogs with HSA, which can provide a new avenue to design more potent chalcone triazole analogs for use in the biomedical field.

The interaction of triazole substituted 4-methyl-7-hydroxycoumarin derivatives (CUM1-4) with serum albumin (bovine serum albumin [BSA] and human serum albumin [HSA]) have been studied employing ultraviolet-visible (UV-Vis), fluorescence, circular dichroism (CD) spectroscopy, and molecular docking methods at physiological pH 7.4. The fluorescence quenching occurred with increasing concentration of CUMs, and the binding constant of CUM derivatives with BSA and HSA obtained from fluorescence quenching experiment was found to be ~ 104 L mol-1 . CD study showed conformational changes in the secondary structure of serum albumin upon titration of CUMs. The observed experimental results were further validated by theoretical studies involving density functional theory (DFT) and molecular docking.

Explosives can be classified into nitroaromatic compounds (NACs), nitrate esters, nitramines and peroxides. Among these, NACs are at the center of extensive literature studies. NACs are stable and useful in many military operations. However, their stability and explosiveness comes with an ever-increasing danger pertaining to their illegitimate use in terrorist activities. Moreover, NACs are toxic, mutagenic and carcinogenic, and hence they need to be screened out of the environment before their levels reach the admissible limits. The development of economical, efficient, sensitive and real-time sensors for combating the threat of NACs is the greatest need of the hour. In this review, we provide a comprehensive discussion of the recent advancements in the field of NAC sensors.

An ecofriendly, magnetically retrievable amine-functionalized SiO2@Fe3O4 catalyst was successfully synthesized and affirmed by several physicochemical characterization tools, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), energy-dispersive X-ray spectroscopy (EDX), and powder X-ray diffraction. Thereafter, the catalytic performance of this environmentally benign NH2@SiO2@Fe3O4 catalyst was investigated in the one-pot multicomponent synthesis of 2-amino-4H-benzo[b]pyran derivatives. The reaction was simply achieved by grinding of various substituted aromatic aldehydes, dimedone, and malononitrile at room temperature under solvent and waste-free conditions with excellent yields and high purity. Moreover, the developed catalyst not only possesses immense potential to accelerate the synthesis of bioactive pyran derivatives but also exhibits several remarkable attributes like broad functional group tolerance, durability, improved yield, reusability, and recyclability. Besides, various other fascinating advantages of this protocol are milder reaction conditions, cost effectiveness, short reaction time, and simple work up procedures.

This work represents the design and synthesis of efficient sulfonated cobalt ferrite solid acid catalyst. The synthesized solid acid green catalyst was characterized using various techniques viz. FT-IR, powder XRD, SEM, TEM and VSM. The obtained catalyst was used to synthesize biologically significant 2-substituted benzimidazole derivatives by condensation between o-phenylenediamine with various aromatic, aliphatic and heterocyclic aldehydes. High yield (up to 98 %), short reaction time (10−25 min), mild reaction condition, wide functional group tolerance, easy work-up procedure and excellent values of green chemistry metrices such as lower E factor (0.126), high RME value (88.83 %), carbon efficiency (100 %) and high atom economy (AE) value (90.65 %), are some salient features of the present catalytic system. Moreover, the catalyst recovery by simply using an external magnet and catalyst reusability up to 7 times without any significant loss in catalytic efficiency are some additional remarkable features of the current protocol.

A new simple and efficient fluorous coupling reagent TriTFET (2,4,6-tris-(2,2,2-trifluoro-ethoxy)-[1,3,5] triazene) has been designed and synthesized for the direct amidation. The use of 5 mol % of TriTFET is good for the amide synthesis from carboxylic acids with amines in moderate to excellent yields (72–96%).

A very efficient chiral organocatalyst was prepared from the readily available cyanuric chloride. The asymmetric catalyst exhibited a highly enantioselective catalytic performance for the alkylation of a glycinate Schiff base, which provides a useful procedure for the enantioselective synthesis of structurally diverse natural and unnatural α-alkyl-α-amino acids.

A pyrene-based optical probe for the real-time and regenerative detection of Cu2+ and Fe3+ at parts-per-million (ppm) levels is demonstrated. Moreover, the quantifiable changes in the fluorescence signal induced by chemical inputs viz. Cu2+, Fe3+, H+ and CN− have been exploited to assemble sequential and “four-input” combinatorial molecular logic circuits. A unique “two-way” security lock has also been devised for enhanced information protection at the molecular level.

Emergence of drug-resistant Plasmodium falciparum strains has led to a situation of haste in the scientific and pharmaceutical communities. Hence, all their efforts are redirected toward finding alternative chemotherapeutic agents that are capable of combating multidrug-resistant parasite strains. In light of this situation, scientists have come up with the concept of hybridization of two or more active pharmacophores into a single chemical entity, resulting in “antimalarial hybrids.” The approach has been applied widely for generation of lead compounds against deadly diseases such as cancer and AIDS, with a proven potential for use as novel drugs, but is comparatively new in the sphere of antimalarial drug discovery. A sudden surge has been evidenced in the number of studies on the design and synthesis of hybrids for treating malaria and may be regarded as proof of their potential advantages over artemisinin-based combination therapy (ACT). However, it is evident from recent studies that most of the potential advantages of antimalarial hybrids, such as lower toxicity, better pharmacokinetics, and easier formulation, have yet to be realized. A number of questions left unaddressed at present need to be answered before this approach can progress to the late stages of clinical development and prove their worth in the clinic. To the best of our knowledge, this compilation is the first attempt to shed light on the shortcomings that are surfacing as more and more studies on molecular hybridization of the active pharmacophores of known antimalarials are being published.

A very efficient chiral organocatalyst was prepared from the readily available cyanuric chloride. The asymmetric catalyst exhibited a highly enantioselective catalytic performance for the alkylation of a glycinate Schiff base, which provides a useful procedure for the enantioselective synthesis of structurally diverse natural and unnatural α-alkyl-α-amino acids.

Alkyl, benzyl, aryl, and hetaryl carboxylic acids are successfully coupled with primary aliphatic and aromatic amines as well as secondary aliphatic amines.

The CAN-catalyzed cycloaddition of nitriles with NaN3 is advantageous with regards to short reaction times, easy work up, and high yields.