The manufacture of alkenyl halides on a larger scale often result in the formation of a mixture of isomers each having individual significant applications while their separation from each other is a strenuous task. Since most of the conventional distillation techniques are known to be intricate, energy consuming and expensive, the quest for an alternative strategy is still continuing. In this context, recently reported trianglimine macrocycle - a new class of intrinsically porous material, is promising in discerning cis isomer from a mixture of cis and trans dichloroethene. In this work, an attempt has been made to apprehend the host-guest inclusion phenomenon accountable for the selectivity of cis over the trans isomers of 1,2-dihaloethene (F, Cl and Br) using molecular dynamics simulation and DFT calculations at ω-B97xd/6-311G+(d,p) level of theory. Our results show that trianglimine can stabilise the cis isomers of the dihaloethenes inside its cavity forming complexes with high interaction energies and the rationale behind the recyclability of the host molecule has been clarified. The outcomes of the calculations bring out the potential utility of this new host architecture to produce highly pure value added chemicals in industries.
Monthly Archives: September 2023
Phytochemical and pharmacological aspects of psoralen‐ A bioactive furanocoumarin from Psoralea corylifolia Linn.
Since long ago, medicinal plants have played a vital role in drug discovery. Being blessed and rich in chemovars with diverse scaffolds, they have unique characteristics of evolving based on the need. The World Health Organization also mentions that medicinal plants remain at the center for meeting primary healthcare needs as the population relies on them. The plant-derived natural products have remained an attractive choice for drug development owing to their specific biological functions relevant to human health and also the high degree of potency and specificity they offer. In this context, one such esteemed phytoconstituent with inexplicable biological potential is psoralen, a furanocoumarin. Psoralen was the first constituent isolated from the plant Psoralea corylifolia, commonly known as Bauchi. Despite being a life-saver for psoriasis, vitiligo, and leukoderma, it also showed immense anticancer, anti-inflammatory, and anti-osteoporotic potential. This review brings attention to the possible application of psoralen as an attractive target for rational drug design and medicinal chemistry. It discusses the various methods for the total synthesis of psoralen, its extraction, the pharmacological spectrum of psoralen, and the derivatization done on psoralen.
Exogenous putrescine changes biochemical (antioxidant activity, polyphenol, flavonoid, and total phenol compounds) and essential oil constituents of Salvia officinalis L.
This research is based on principal component analysis (PCA) and calculation of selection criteria (SC) to investigate the effect of foliar spraying of polyamine putrescine on essential oil yield, essential oil compounds, antioxidant activity, and biochemical compounds (polyphenol, flavonoid, and total phenol compounds) of Salvia officinalis. The treatments used included four levels of putrescine, Put (Control: 0, Put1: 500, Put2: 1000, and Put3: 1500 mg L− 1) with five replications. Based on our results, four factors had eigenvalues ≥ 1 and showed a cumulative variance percentage of 92.57% by applying different concentrations of putrescine. According to the results of this research, putrescine had significant effects on the amount of total phenolic compounds, flavonoids, and antioxidant activity. The crucial essential oil compounds of different Put treated sage were: cis- thujone (35.34%), Camphor (15.60%), trans- thujone (9.90%), 1,8- cineole (9.46%), α-Humulene (3.85%), α- pinene (3.50%) and limonene (1.23%). The results showed that the amount of total phenol, the phenolic composition of catechin, and the antioxidant activity of sage plant extract increased significantly when putrescine was used at 1000 mg/liter. Results can use the current research to optimize the production management of medicinal plants and improve the quality of their products.
Impact of dielectric constant of solvent on the formation of transition metal‐ammine complexes
Abstract
The DFT-level computational investigations into Gibbs free energies (ΔG) demonstrate that as the dielectric constant of the solvent increases, the stabilities of [M(NH3) n ]2+/3+ (n = 4, 6; M = selected 3d transition metals) complexes decrease. However, there is no observed correlation between the stability of the complex and the solvent donor number. Analysis of the charge transfer and Wiberg bond indices indicates a dative-bond character in all the complexes. The solvent effect assessed through solvation energy is determined by the change in the solvent accessible surface area (SASA) and the change in the charge distribution that occurs during complex formation. It has been observed that the SASA and charge transfer are different in the different coordination numbers, resulting in a variation in the solvent effect on complex stability in different solvents. This ultimately leads to a change between the relative stability of complexes with different coordination numbers while increasing the solvent polarity for a few complexes. Moreover, the findings indicate a direct relationship between ΔΔG (∆G solvent-∆G gas) and ΔE solv, which enables the computation of ΔG for the compounds in a particular solvent using only ΔG gas and ΔE solv. This approach is less computationally expensive.
[ASAP] Electrifying Carbon Capture by Developing Nanomaterials at the Interface of Molecular and Process Engineering
Accounts of Chemical Research
DOI: 10.1021/acs.accounts.3c00321
[ASAP] Self-Assembly via Condensation of Imine or Its N-Substituted Derivatives
Accounts of Chemical Research
DOI: 10.1021/acs.accounts.3c00475
[ASAP] (Photoredox) Organocatalysis in the Emergence of Life: Discovery, Applications, and Molecular Evolution
Accounts of Chemical Research
DOI: 10.1021/acs.accounts.3c00396
Challenges and Breakthroughs in Z‐Enantioselective Olefin Metathesis
Asymmetric Olefin Metathesis (AOM) represents a highly versatile synthetic tool to lead to relevant chiral building blocks with excellent enantiopurity. As the Z-alkene moiety is ubiquitous in a wide range of natural products, the development of catalysts which are able to control both the Z-selectivity and the enantioselectivity of metathesis transformations is in high demands. This review aims to provide a comprehensive overview covering all the breakthroughs accomplished in the field of challenging Z-enantioselective olefin metathesis, which is of interest in the total synthesis of complex molecules.
K2S2O8 Mediated C‐3 Formylation of Imidazopyridines Using Glyoxylic Acid
A metal-free formylation of imidazopyridines with K2S2O8 via direct decarboxylative cross-coupling of glyoxylic acid is described. This reaction features broad substrate scope, good functional group tolerance, and generate products in good yields. The involvement of radicals in the course of the reaction has been demonstrated by radical trapping experiments with 2,2,6,6-tetramethylpiperidine-1-oxyl and 2,6-di-tert-butyl-4-methylphenol (BHT).
Valeric Biofuels from Biomass‐Derived γ‐Valerolactone: A Critical Overview of Production Processes
This review analyzes critically the production of valeric biofuels from γ-valerolactone, a relevant biomass-derived platform molecule. Initially, the main properties of valeric esters as fuels for spark- and compression-ignition engines are summarized. Then, catalytic routes to valeric esters from γ-valerolactone are meticulously analyzed, describing the acid- and metal-catalyzed reactions taking part in the tandem catalysis. Only works focused on the production of the valeric biofuels were considered, excluding the cases where these esters were observed in minor amounts or as byproducts. The role of the appropriate selection of the support, catalytic species, catalyst preparation and experimental conditions on the valeric ester productivity are thoroughly commented. Finally, some concluding remarks and perspectives are given, mentioning the areas where additional efforts must be done in order to turn the dream of a massive and renewable valeric biofuel production into a reality.