New Possibilities of the Kabachnik–Fields and Pudovik Reactions in the Phthalocyanine-Catalyzed Syntheses of α-Aminophosphonic and α-Aminophosphinic Acid Derivatives

The results of systematic studies demonstrated wide possibilities of the three-component Kabachnik–Fields and two-component Pudovik reactions catalyzed by metal phthalocyanines in the synthesis of structurally diverse α-aminophosphonates. Extension of this catalytic method to the synthesis α-aminophosphinates gave rise to a series of α-amino- and α-hydrazinophosphinates based on biogenic amino acids. A number of α-hydrazinophosphonates showed a good antioxidant activity.     

The Synthesis of Some Novel N-[α-(Isoflavone-7-O-) Acetyl]Amino Acid Derivatives

IsoflavonoidsarebiologicallyimportantnaturalproductsoccurringmainlyinspeciesoftheLeguminosaefamilyandhaveshownawidespectrumofbiologicalactivitiesincludingestrogenic,anticancer,insecticidal,pisciadalandantifungalproperty'.Theseisoflavonoidphytoestrogensarerichinsomeplantdietsuchassoybean'.Animalexperimentshadshownthatsoybeandietinhibitradiation-andchemical-inducedtumorofthemammary',skin',andlivers.AstudyconductedbyBarnesetal.6suggestedthatsoybeanisoflavonesmayberesponsiblefortheanticarcinogeni…     

Regio- and Diastereoselectivity in the Thiomethylation of α-(1-Hydroxyalkyl)acrylate Derivatives

The regio-and diastereoselectivity of reactions of selected α-(1-hydroxyalkyl)acrylate derivatives with sodium methanethiolate have been investigated. The hydroxy compounds typically undergo conjugate addition with up to 66% d.e., while the acetoxy and bromo analogues favour S_N' and S_N reactions, respectively.     

Synthesis and Crystal Structure of α-(3-Phenylureido)-α-(2,4-Dichlorophenyl) Methyl Phenylphosphinic Acid

1INThODUCT1ONInaprevi0uspaPer"',wereP0rtedthesyntheses0fsome1,3,4-diazaphospho-lidin-2-thione-4-oxidesandtheirhighselectiveherbicidalactivity.Althoughtherewereseveralreportsaboutthedesulphurisationofsomestraightchainthioureaderiva-tivest2'31,uptonow,thedesulphurisationreactionofcyclicthioureaderivativesutiliz-ingAgNO,-H,Osystemhasnotbeenstudied.InthispaPer,thedesulphurisation0fcis-3,4-diphenyl-5-(2,4-dichlorophenyl)-1,3,4-diazaphOSpholidin-2-thione-4-oasthecyclicsubstrateisrep0rtedfort…     

Stereoselective and Convenient Synthesis of Diethyl (E)-α-Triphenylstannyl or (Z)-α-Tributylstannyl α-Alkenylphosphonates

Diethyl (E)-α-triphenylstannyl or (Z)-α-tri-n-butylstannyl α-alkenylphosphonates are conveniently and stereoselectively prepared using a “tin-Peterson-like” reaction. Protonolysis of the carbon-tin bond of α-tributylstannyl derivatives proved to be easy and stereospecific.     

Effect of Salicylic Acid on the Activity of PAL and PHB Geranyltransferase and Shikonin Derivatives Production in Cell Suspension Cultures of Arnebia euchroma (Royle) Johnst—a Medicinally Important Plant Species

Cell suspension cultures of Arnebia euchroma were established from the friable callus on liquid Murashige and Skoog medium supplemented with 6-benzylaminopurine (10.0 μM) and indole-3-butyric acid (5.0 μM). Salicylic acid was used to study its effect on the enzymes which participate in shikonin biosynthesis with respect to metabolite (shikonin) content in the cell suspension culture of A. euchroma. In our study, phenylalanine ammonia lyase and PHB geranyltransferase were selected from the entire biosynthetic pathway. Results showed that phenylalanine ammonia lyase is responsible for growth and PHB geranyltransferase for metabolite production. Salicylic acid exhibited an inverse relationship with the metabolite content (shikonin); salicylic acid (100 μM) completely inhibited shikonin biosynthesis. The results presented in the current study can be successfully employed for the metabolic engineering of its biosynthetic pathway for the enhancement of shikonin, which will not only help in meeting its industrial demand but also lead to the conservation of species in its natural habitat.     

Novel Phosphonoacetic Acid Derivatives.Synthesis of N-(Ethoxycarbonylmethylphosphonyl)-α-Amino Esters and-α-Amino Phosphonic Acid Esters and Their Bioactivities

PhopendcaCulopA)anditsanalog.PhoSP~cedd(PAA,havboknOWntohavPOtentantiviIalaCtivityagainStviruses,withetw~exvirustwIndIIcoV-I,HSVap['].~r,PAAaPpearStohavahightwforbOnthaIhaypeitsuseinhumans[21,wh~PFAhas~eddricallya~HSVIndHSV-if'l.Here,wedesgnedndSynthesiredanUmberofnewderiv~s(DOfPAAwiththendofpotenhatinitSboactivity~endnigtokicdri,atthesamtiIntostiInulatetheactivityofatnineddsorndnoPhoSPhoulcottyPhOSPhonyation.Intbenew~theNedofamineddsoraminPhoSPhotheotwasbonantoghatomor…     

Catalytic Mechanism of a Heme and Tyrosyl Radical-Containing Fatty Acid α-(Di)oxygenase

The steady-state catalytic mechanism of a fatty acid α-(di)oxygenase is examined, revealing that a persistent tyrosyl radical (Tyr379(?)) effects O(2) insertion into C(α)-H bonds of fatty acids. The initiating C(α)-H homolysis step is characterized by apparent rate constants and deuterium kinetic isotope effects (KIEs) that increase hyperbolically upon raising the concentration of O(2). These results are consistent with H(?) tunneling, transitioning from a reversible to an irreversible regime. The limiting deuterium KIEs increase from ～30 to 120 as the fatty acid chain is shortened from that of the native substrate. In addition, activation barriers increase in a manner that reflects decreased fatty acid binding affinities. Anaerobic isotope exchange experiments provide compelling evidence that Tyr379(?) initiates catalysis by H(?) abstraction. C(α)-H homolysis is kinetically driven by O(2) trapping of the α-carbon radical and reduction of a putative peroxyl radical intermediate to a 2(R)-hydroperoxide product. These findings add to a body of work which establishes large-scale hydrogen tunneling in proteins. This particular example is novel because it involves a protein-derived amino acid radical.     

Cyclization of α- and β-amino ketones. (Review)

In this review data on the synthesis of three-, four-, five-, and six-membered heterocycles, as well as of condensed heterocyclic compounds from -amino ketones and Mannich bases are classified for the first time.Samara State Technical University, Samara 433100, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 723–735, June, 1999.     

Oxidation of Aryl Alkyl Ketones To α-Acyloxy, α-(Camphorsulfonyloxy), or α-Hydroxy Derivatives Using Manganese(III) Acetate in Combination with Carboxylic Acids or (1S)-(+)-10-Camphorsulfonic Acid

The α-oxidation of aryl alkyl ketones using manganese(III) acetate in the presence of various carboxylic acids and (1S)-(+)-10-camphorsulfonic acid provided a convenient synthesis of α-acyloxy, α-(10-camphorsulfonyloxy), and α-hydroxy derivatives in good yield.     

Influence of α- and β-Cyclodextrins on the Separation of Positional Isomers of Benzoic Acid Nitro, Amino, Chloro, and Hydroxy Derivatives by Capillary Electrophoresis

The positional isomers of nitro-, amino-, chloro-, and hydroxybenzoic acids were separated by capillary electrophoresis. The introduction of 1 to 10 mM of natural - and -cyclodextrins into the background electrolyte significantly enhanced the resolution of the capillary electrophoresis system in its zone version, while the isomers were not separated in the absence of cyclodextrins (CDs). Additives of both individual CDs and their mixtures were used. Micellar electrokinetic chromatography with or without CD additives was used for the separation of analytes along with capillary zone electrophoresis.     

Reduction of Derivatives of α-Arylidene-α-(2-Thiazolyl)acetonitrile with Lithium Aluminum Hydride

The action of lithium aluminum hydride on derivatives of -arylidene--(2-thiazolyl)acetonitrile in absolute ether leads to reduction of the nitrile group without affecting the double bond conjugated with it. The reaction products are the corresponding substituted allylamines.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 221–224, February, 2005.     

Synthesis and Herbicidal Activity of 3-Subsituted Amino-6-(substituted phenoxyl)pyridazine Derivatives

In recent years, many pyridazine derivatives have shown highly biological activities, such as fungicides, insecticides and herbicides. Especially, the researches of 3-(substituted phenoxyl)pyridazine derivatives have become the focus of pesticidal chemistry.     

Preparation and Application of Perchloric Acid Supported on Alumina (Al2O3-HClO4) to the Synthesis of α-(α-Amidobenzyl)-β-naphthols

Preparation of perchloric acid supported on alumina and its primary application as a solid supported heterogeneous catalyst to the synthesis of α-(α-amidobenzyl)-β-naphthols by a one-pot, three-component condensation of benzaldehydes, β-naphthol and acetamide or benzamide under thermal solvent-free conditions were described. The present methodology offers several advantages such as simple procedure, shorter reaction time, and excellent yields.     

Studies on Pyrazine Derivatives,XLV: Synthesis,Reactions, and Tuberculostatic Activity of N-Methyl-N′-(pyrazine-2-carbonyl)-hydrazinecarbodithioic Acid Methyl Ester

Methyldithiocarbonyl derivative 2 of pyrazine-2-carboxylic acid N′-methyl-hydrazide 1 was synthesized by methylation of CS₂ adduct. Benzylamine caused the decomposition of compound 2 to pyrazine-2-carboxylic acid benzylamide 5 and 1,3-dibenzylthiourea 6. N-methyl-N′-(pyrazine-2-carbonyl)-hydrazinecarbodithioic acid methyl ester 2 were evidenced to cyclize to 3-methyl-5-pyrazin-2-yl-3H-[1, 3, 4]oxadiazole-2-thione 8 in the presence of triethylamine. In the reactions with secondary amines such as morpholine, pyrrolidine and phenylpiperazine pyrazinoyl derivatives (9–11) of thiosemicarbazide were obtained. Hydrazine, methylhydrazine, aminoalcohols, and N-alkylamino-substituted cyclic amines reacted with cyclization to 4-substituted 1,2,4-triazole-3-thiones 12, 13, and 18–22. Synthesized compounds exhibited low tuberculostatic activity in vitro (MIC 50–100 μg/mL).     

Helioal Structure and Optical Activity of Two New Derivatives of R( )-1,1'-Binaphthyl-2,2'-diol

Inourpreviousworkl'2wehaddesignedandsynthesisedaseriesofmodelcyclicesterswithL-( )-2,3-O-isopropylidenethreitolforinvestigatingtherelationshipbetweenthebeliealstructureandopticalactivityofchiralmolecules.Asasequeltothisapproach,wenowreporttwoprototypemolecules,3and4,ofanewseriesofmodelcompounds.Thechiralityandhelicityofcompounds3and4originatefromR-( )-l,l'-binaphthyl-2,2'diol1,wherebycolourlesscrystallinesubstances3and43'4wereobtainedfromthereactionofdiol1withoxalylandphthaloyldichlorides,res…     

Design and Synthesis of Novel Aryloxyalkyl-arylpiperazine Derivatives as α_(1A)-Adrenoceptor Antagonists

Benign prostatic hyperplasia (BPH) is the non-malignant enlargement of the prostate andclinically occurs predominantly in men aged over 60 years1. α1-Adrenoceptor (α1-AR)antagonists such as terazosin and doxazosin relax the smooth muscle in the prostate andlower urinary tract and are currently being used as treatment for BPH2,3. These clinicalagents, while effective, have been associated with side effects such as orthostatichypotension, dizziness, asthenia, and nasal congestion4. …     

Diastereoselective Synthesis of Enantiopure α-Aminophosphonic Acid Derivatives: Pudovik Reaction in Stereoselective Synthesis (Dedicated to A. N. Pudovik, 1916–2006)

In this report, we present the application of Pudovik reaction in the synthesis of chiral organophosphorus compounds and shown this reaction to be a promising way to enantiopure aminophosphonic acid derivatives. Cyclization reactions are a new, most efficient strategy for stereoselective synthesis of α-aminophosphonates, namely an intramolecular type of interaction of the P(III) atom and an imino group.     

Preparation of α-Ketophosphonate Derivatives and Their Application in the Synthesis of 1-(N-Alkylcarbamoyl)-1-(diethoxyphosphoryl)alkyl Benzoates via Passerini Reaction

Abstract

The Passerini reaction of α-ketophosphonates, isocyanides, and benzoic acid derivatives leads to 1-(N-alkylcarbamoyl)-1-(diethoxyphosphoryl)alkyl benzoates in one step at room temperature. The structures of products were assigned on the basis of their ¹H NMR, ¹³C NMR, ³¹P NMR, and IR spectroscopic data.

GRAPHICAL ABSTRACT