An efficient synthesis of phosphoramidates from halides in aqueous ethanol

Selenium-catalyzed allylic C-H phosphoramidation of alkenes

We report herein a synthesis of allylic phosphoramidates from alkenes by selenium-catalyzed allylic C-H derivatization. This method features mild conditions, broad substrate scope, and high functional group tolerance, enabling late-stage modification of a number of complex substrates. In addition, this protocol was applied to modify caryophyllene and produced a photoaffinity probe capable of proteomic target labeling in live HeLa cells.

Recent advances in metal directed C-H amidation/amination using sulfonyl azides and phosphoryl azides

Transition metal-catalyzed C-N bond formation reactions have gained popularity as a method for selectively transforming common C-H bonds into N-functionalized molecules. This approach is particularly useful for synthesizing aminated molecules, which require aminating reagents and amidated building blocks. Over the past two decades, significant advancements have been achieved in transition-metal-catalyzed C-H functionalization, with organic azides emerging as promising amino sources and internal oxidants. This review focuses on recent developments in utilizing sulfonyl and phosphoryl azides as building blocks for directed intra- and intermolecular C-H functionalization reactions. Specifically, it discusses methods for synthesizing sulfonamidates and phosphoramidates using sulfonyl and phosphoryl azides, respectively. The article highlights the potential of C-H functionalization reactions with organic azides for efficiently and sustainably synthesizing N-functionalized molecules, providing valuable insights into the latest advancements in this field.

Recent bioanalytical methods for the isolation of bioactive natural products from genus Codonopsis

INTRODUCTION

Chromatography and spectroscopy are nowadays well-validated techniques allowing to isolate and purify different class of natural products from the genus Codonopsis. Several categories of phytochemicals with drug like properties have been selectively extracted, isolated, characterised by this methodology.

OBJECTIVES

The present review aims to provide up-to-date and comprehensive information on the chromatography, phytochemistry and pharmacology of natural products of Codonopsis with an emphasis on the search for natural products having various biological activities and the semi-synthetic derivatives of bioactive ones and to highlight current gaps in knowledge.

MATERIALS AND METHODS

A literature search was performed in the SciFinder Scholar, PubMed, Medline, and Scopus databases.

RESULTS

During the period covered in this review, several classes of compounds have been reported from genus Codonopsis. Codonopsis pilosula and Codonopsis lanceolata are the most popular in the genus especially as per phytochemical and bioactive studies. Phytochemical investigation demonstrates that Codonopsis species contain mainly xanthones, flavonoids, alkaloids, polyacetylenes, phenylpropanoids, triterpenoids and polysaccharides, which contribute to numerous bioactivities. The major bioactive compounds isolated were used for semi-synthetic modification to increase the chance to discover lead compound.

CONCLUSIONS

It can be concluded that genus Codonopsis has been used as traditional medicines and food materials around the world over years due to chemical constituents with diverse structural types, exhibiting extensive pharmacological activities in immune system, blood system, cardiovascular system, central nervous system, digestive system, and so forth, with almost no obvious toxicity and side effect. Therefore, Codonopsis can be used as a promising ethnopharmacological plant source.

Risk assessment, development and validation of a GC-ECD-based method for the quantification of cypermethrin from green pea

The present work describes the persistence, dissipation behaviour, half-life, risk assessment and novel gas chromatography method for the residue estimation of cypermethrin in green pea by spraying cypermethrin 10EC at 50 g a.i. ha-1 at fruiting stage followed by another application at a 10 day interval. The sample extraction and cleanup was followed bya modified quick, easy, cheap, effective, rugged, and safe method, and the residues of cypermethrin were determined using a validated gas chromatography method. The initial deposits were found to be 1.21 mg kg-1 following the application of insecticide at 50 g a.i. ha-1 . Cypermethrin residues declined to below the detection limit of 0.05 mg kg-1 after 15 days at the recommended dosage. The half-life of cypermethrin was 2.66 days at 50 g a.i. ha-1 . For risk assessment studies, the waiting period of 15 days is recommended as safe for consumption for the insecticide. The GC-ECD method was validated according to the SANTE guidelines by various analytical parameters including linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable, and can be used for the standardization of pesticides on fruits and vegetables.

Development, method validation and simultaneous quantification of eleven bioactive natural products from high altitude medicinal plant by high performance liquid chromatography

Herein, a novel, rapid, reliable, simple method validation and simultaneous quantification of eleven bioactive compounds mostly xanthones have been described. ICH guidelines were used for the analytical method validation. Good linearity, repeatability, intra-day and inter-day precision, accuracy and reliability is well illuminated in the method validation procedure. The calibration curves showed a good linear relationship (r>0.999) within test range. Precision was evaluated by intra- and inter-day tests with RSDs <2.79%, accuracy validation recovery 74.16-91.84%. On quantification study, validated method described the high content of bioactive xanthone derivative including 1-hydroxy-3, 5-dimethoxyxanthone (7), 2-(allyloxy)-8-hydroxy-1, 6-dimethoxyxanthone (6) 1, 7, 8-trihydroxy-3-methoxyxanthone (9) and Coxanthone E (5) in the C. ovata which is advantageous due to numerous pharmacological and biological effects associated with these compounds mostly anti-cancers, antioxidant, anti-inflammatory, anti-mutagenic and anti-obesity activity. The bulk abundance of these compounds can also be used for the further modification to produce better lead molecules for drug discovery with low toxicity and high potency. The proposed method makes it possible to determine simultaneously all bioactive compounds in one run and can be extended for marker based standardization of herbal formulations in medicinal and pharmaceutical industries.

Recent advances in the synthesis and applications of phosphoramides

Phosphoramide, as an important framework of many biologically active molecules, has attracted widespread attention in recent decades. It is not only widely used in pharmaceuticals because of its excellent biological activities, but it also shows good performance in organic dyes, flame retardants and extractors. Thus, it is of great significance to develop effective and convenient methods for the synthesis of phosphoramides. In this review, the recent advancements made in the synthesis routes and applications of phosphoramides are discussed. The synthetic strategies of phosphoramides can be separated into five categories: phosphorus halides as the substrate, phosphates as the substrate, phosphorus hydrogen as the substrate, azides as the substrate and other methods. The latest examples of these methods are provided and some representative mechanisms are also described.

CDATA[Recent Advances in the Development of 1,2,3-Triazole-containing Derivatives as Potential Antifungal Agents and Inhibitors of Lanoster ol 14α-Demethylase

1,2,3-Triazole, a five-membered heterocyclic nucleus, is widely recognized as a key chromophore of great value in medicinal chemistry for delivering compounds possessing innumerable biological activities, including antimicrobial, antitubercular, antidiabetic, antiviral, antitumor, antioxidants, and anti-inflammatory activities. Mainly, in the past years, diverse conjugates carrying this biologically valuable core have been reported due to their attractive fungicidal potential and potent effects on various infective targets. Hence, hybridization of 1,2,3-triazole with other antimicrobial pharmacophores appears to be a judicious strategy to develop new effective anti-fungal candidates to combat the emergence of drug-sensitive and drug-resistant infectious diseases. Thus, the current review highlights the recent advances of this promising category of 1,2,3-triazole-containing hybrids incorporating diverse varieties of bioactive heterocycles such as conozole, coumarin, imidazole, benzimidazole, pyrazole, indole, oxindole, chromene, pyrane, quinazoline, chalcone, isoflavone, carbohydrates, and amides. It underlies their inhibition behavior against a wide array of infectious fungal species during 2015-2020.

Evaluation and Development of Methodologies for the Synthesis of Thiophosphinic Acids

Thiophosphorus acids R¹R²P(S)OH constitute an important class of organophosphorus compounds, in which the phosphorus atom is intrinsically chiral if R¹ ≠ R². In connection with a project aimed at the preparation of chiral thiophosphorus acids, various available literature methods were considered, but few fit the requirement of odorless reagents. Herein, the results of our studies on the synthesis of thiophosphinic acids are reported. Ultimately, two major approaches were selected: (1) the Stec reaction of phosphorus amides with carbon disulfide; and (2) the one-pot synthesis of thiophosphorus acids from H-phosphinates, an organometallic nucleophile, and quenching with elemental sulfur. An application to the preparation of a potential chiral phosphorus organocatalyst is also reported.

Opening up the Toolbox: Synthesis and Mechanisms of Phosphoramidates

This review covers the main synthetic routes to and the corresponding mechanisms of phosphoramidate formation. The synthetic routes can be separated into six categories: salt elimination, oxidative cross-coupling, azide, reduction, hydrophosphinylation, and phosphoramidate-aldehyde-dienophile (PAD). Examples of some important compounds synthesized through these routes are provided. As an important class of organophosphorus compounds, the applications of phosphoramidate compounds, are also briefly introduced.

Allylic azides: synthesis, reactivity, and the Winstein rearrangement

Organic azides are useful synthetic intermediates, which demonstrate broad reactivity. Unlike most organic azides, allylic azides can spontaneously rearrange to form a mixture of isomers. This rearrangement has been named the Winstein rearrangement. Using allylic azides can result in low yields and azide racemization in some synthetic contexts due to the Winstein rearrangement. Effort has been made to understand the mechanism of the Winstein rearrangement and to take advantage of this process. Several guiding principles can be used to identify which azides will produce a mixture of isomers and which will resist rearrangement. Selective reaction conditions can be used to differentiate the azide isomers in a dynamic manner. This review covers all aspects of allylic azides including their synthesis, their reactivity, the mechanism of the Winstein rearrangement, and reactions that can selectively elaborate an azide isomer. This review covers the literature from Winstein's initial report to early 2019.

Method validation and simultaneous quantification of eight organochlorines/organophosphates in apple by gas chromatography

BACKGROUND

The increasing and extensive use of pesticides worldwide has resulted in a significant loss of non-target populations particularly humans by direct or indirect exposures. Also, various methods have been used for the estimation of pesticide residues in fruits and vegetables from recent past which are either tedious, time consuming or expensive. Therefore, the present study was performed to determine the pesticide residues from apple by simple and novel validated gas chromatography.

RESULTS

A novel, accurate, ecofriendly and cost-effective gas chromatography method was developed for simultaneous quantification of eight pesticides, namely chlorpyrifos-methyl (1), chlorpyrifos (2), quinolphos (3), profenofos (4), myclobutnil (5), ethion (6), fenpropathrin (7) and cypermethrin (8). The developed method was validated as per the SANTE guidelines. All calibration curves showed a good linear relationship (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day tests with relative standard deviations (RSDs) < 2.0%, recovery in between 70% and 120% with RSDs < 2.00%.

CONCLUSION

The results demonstrate that the concentration of pesticides 1 to 8 were found below the detectable limit. Method validation parameters like linearity, precision, accuracy, specificity, robustness, detection and quantification limits were found within the acceptable range. The proposed method makes it possible to determine simultaneously pesticides 1-8 in one run which can be extended for residue-based standardization of pesticides from apple and other fruits and vegetables. © 2019 Society of Chemical Industry.

Reinvestigation of the iodine-mediated phosphoramidation reaction of amines and P(OR)3 and its synthetic applications

A systematic study on the iodine-mediated phosphoramidation reaction of amines and trialkyl phosphites was conducted, which not only disclosed the factors affecting the reaction but also revealed that it could proceed smoothly in CH2Cl2 at room temperature in open air. Using this method, various phosphoramidates with different aliphatic amines and aromatic amines were synthesized in good to excellent yields. Our present investigation shows that this underused method is actually a mild, practical and general way to synthesize phosphoramidates and will have wide applications.

Medicinal attributes of 1,2,3-triazoles: Current developments

1,2,3-Triazoles are important five-membered heterocyclic scaffold due to their extensive biological activities. This framework can be readily obtained in good to excellent yields on the multigram scale through click chemistry via reaction of aryl/alkyl halides, alkynes and NaN₃ under ambient conditions. It has been an emerging area of interest for many researchers throughout the globe owing to its immense pharmacological scope. The present work aims to summarize the current approaches adopted for the synthesis of the 1,2,3-triazole and medicinal significance of these architectures as a lead structure for the discovery of drug molecules such as COX-1/COX-2 inhibitors (celecoxib, pyrazofurin), HIV protease inhibitors, CB1 cannabinoid receptor antagonist and much more which are in the pipeline of clinical trials. The emphasis has been given on the major advancements in the medicinal prospectus of this pharmacophore for the period during 2008-2016.

K2CO3-promoted aerobic oxidative cross-coupling of trialkyl phosphites with thiophenols

Phosphorylation of thiols has been achieved via K₂CO₃-promoted aerobic oxidative cross-coupling of trialkyl phosphites with thiophenols.