New Chemistry of Enol Phosphates

Applications of enol phosphates in the synthesis of novel bicyclic 1,3-dienes, bi- and polycyclic aromatic derivatives, and f -hydroxy ketones are described.     

Highly Selective Arbuzov Reaction of α-Chlorocarbonyl Compounds with P(OEt)3 and Substituted Amino Urea

Abstract

A facile one—pot Arbuzov reaction of α-chlorocarbonyl compounds with P(OEt)₃ and substituted amino urea is described. The highly selective Arbuzov reaction of α-chlorocarbonyl compounds could take place under relatively mild conditions, giving products in high yields.     

Microwave Assisted Synthesis of Biologically Active α-Aminophosphonates Catalyzed by Nano-BF3·SiO2 under Solvent-Free Conditions

Abstract

An efficient and high-yield synthesis of a class of new α-aminophosphonate derivatives as diethyl α-aryl/2-thienyl-α-[2-(phenylthio)phenylamino]methylphosphonates 6a–j in short reaction times from three component coupling reactions (Kabachnik-Fields reaction) of 2-aminodiphenylsulfide 3, substituted phenyl/heterocyclic aldehydes 4a–j, and diethyl phosphite 5 is reported. The reaction proceeds smoothly in the presence of the catalyst, nano-silica-supported boron trifluoride (BF₃·SiO₂) without using solvent under microwave irradiation. The title compounds were tested for in vitro antibacterial and antifungal activities at concentrations of 100 and 200 μg/disc. Minimum inhibitory concentrations (MICs) were also examined.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures and tables.     

Preparation of New Dialkyl Benzene-, Biphenyl-, and Naphthalene-bis(α-oxoethanedithioates)

Novel arene-bis- and -tris(α-oxoethanedithioate) esters of the benzene, the biphenyl, and, in particular, the naphthalene series were prepared by reaction of the corresponding diazoacetyl or bromoacetyl derivatives with elemental sulfur in the presence of triethylamine in dry DMF, and subsequent direct alkylation of the produced dithiocarboxylate anions. The thiolation reaction of the diazoketones was significantly promoted by the addition of anhydrous calcium chloride (calcium chloride–activated thiolation, or CAT). Certain carbonyl-activated methylene and methyl compounds exhibiting no bromo or diazo substituents could be also transformed into dithioesters by the CAT reaction. The structure of three dithioesters was corroborated by X-ray structural analyses.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

A Proline-Based Aminophosphinic Acid Ligand and It’s Vanadyl Complex: Synthesis,Characterization and In Vitro Inhibitory Effects on α-Amylase And α-Glucosidase

Abstract

A proline-based aminophosphinic acid ligand and it's vanadium complex have been synthesized and characterized by spectroscopic techniques. The inhibitory activity on pancreatic α-amylase and Baker's yeast α-glucosidase has been examined in vitro. The novel complex showed more inhibitory potency against pancreatic α-amylase and Baker's yeast α-glucosidase compared to acarbose as an antidiabetic drug.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and Antimicrobial Activities of Diphenyl(Arylamino)(1-Phenyl-3-(Pyridin-2-Yl)-1H-Pyrazol-4-Yl)Methylphosphonates

Abstract

A series of novel diphenyl(arylamino)(1-phenyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl)methylphosphonates have been synthesized in high yields. They were screened for their antibacterial activities against Escherichia coli (NCIM2065) as a Gram-negative bacterium, Bacillus subtilis (PC1219) and Staphylococcus aureus (ATCC25292) as Gram-positive bacteria, and Schccaromycies cerevisiae as a fungus. The minimum inhibitory concentrations (MICs) of the synthetic compounds showed moderate antibacterial and antifungal activities at low concentrations (10–1000 μg/mL).

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

P-Chiral Thioxaphosphoranesulphenyl Chlorides RR1 P(S)SC1. A New Tool in Stereochemistry of Organophosphorus-Sulphur Compounds

Abstract

Phosphoranesulphenyl halides of the general formula RR'P(Y)SX and their selenium analogues RR'P(Y)SeX (X=Cl,Br; Y=O,S) have been shown to be useful intermediates for access to many new classes of compounds con-taining phosphorus, sulphur, or selenium centers.'     

A New View of the Mechanistic Pathways in the Iodine Atom Transfer Addition Reaction Involving 1-Iodoalkylphosphonates and Related Nonphosphorus Systems

The title reaction in the initiation step proceeds via two mechanistic pathways involving attack of the isobutyronitrile radical either on the starting iodide or on the starting alkene or alkyne followed by the reaction of the adduct radical with the iodide.     

Ketene dithioacetal mediated synthesis of 1,3,4,5-tetrasubstituted pyrazole derivatives and their biological evaluation

Abstract

Ketene dithioacetal mediated chemo- and regioselective synthesis of a series of novel 1,3,4,5-tetrasubstituted pyrazole derivatives (4a-l) integrated with a bioactive indole nucleus was achieved by reacting substituted 2-(1-methyl-1H-indole-3-carbonyl)-3,3-bis-(methylthio)-acrylonitrile (2) and substituted phenyl hydrazine hydrochloride (3) in the presence of a catalytic amount of anhydrous K₂CO₃ under reflux conditions. The structures were ascertained by ¹H NMR, NOESY, ¹³C NMR, FT-IR, and HRMS data. In vitro cytotoxicity evaluation of the synthesized compounds against MCF 7 (breast carcinoma) and normal Vero (monkey kidney) cell lines revealed that the compound 5-(5-Bromo-1-methyl-1H-indol-3-yl)-1-(4-cyano-phenyl)-3-methylsulfanyl-1H-pyrazole-4-carbonitrile (4k) showed significant cytotoxicity against MCF 7 (GI₅₀ = 15.6 µM) with low cytotoxicity against normal Vero cell line. Most of the synthesized compounds were also found to possess excellent anti-inflammatory and antioxidant (DPPH, NO, H₂O₂ and SOR) potential.     

Progress in Synthetic Polymers Based on Natural Amino Acids

α-Amino acids are one type of the main building blocks of living systems, being the primary components of all naturally occurring peptides and proteins. They are the simplest optically active compound in the nature and have multiple functional groups, which enable them to be transformed into a wide variety of optically active substances. The resulting materials show a wide variety of functions such as electron transfer, information transfer, photo reactivity and selective catalytic function, which cannot be imitated by synthetic compounds. Functional macromolecular materials using biological chiral resources such as amino acids have been drawing much interest due to their biocompatibility and biodegradability easing the ecological trouble because amino acid residues can be targeted for cleaving by different enzymes. Also, this type of polymer contains nitrogen, which the organism needs for their growth and shows excellent hydrophilic character, reasonably high melting points and good materials properties even at relatively low molecular weights. However, polymers composed of amino acids alone have limited thermal stability and are insoluble in many common organic solvents, which make these materials difficult to fabricate and utilize. Preparation of hybrid systems between conventional synthetic polymers and linear sequences of amino acids are interesting because amino acid segments possess unique properties, such as directional polarity, chirality and their capability to undergo specific noncovalent interactions. These properties can potentially be used for designing novel hierarchical superstructures with tunable material properties for a wide variety of applications. Herein, the synthesis and properties of synthetic macromolecules having natural amino acids are reviewed in details up to now with excluding polypeptides.