Studies on Phosphonium Ylides-XXIII: The Behavior of Active and Stabilized Phosphonium Ylides Towards Thiohydantoins

Thiohydantoin 1 reacts with 2-oxovinylidenetriphenylphosphorane (2) to give 1-methyl-2-thioxo-6-(triphenyl-λ⁵-phosphoranylidene)-hexahydro-furo[2,3-d]imidazol-5-one (5). On the other hand, when 1 reacts with phosphorus ylides 3a–d, the respective olefinic adducts 6a, 6b, 8, and the dimeric product 7 were obtained together with triphenyl-phosphine oxide. Moreover, the application of reagent 4 on 1 renders the new product 4-methyl-2,3-diphenyl-2,3,4,6-tetrahydro-1-oxa-1,3,4,6-tetra-azapentalene-5-thione. Mechanisms accounting for the formation of the products are presented based on analytical and spectroscopic data.     

Further Insight into the Reactivity of Oxazinones Toward Phosphorus Reagents

Abstract

A series of quinoline derivates has been obtained from the reaction of 3‐phenyl‐2,4‐benzoxazin‐1‐one (1) with alkylidenephosphoranes. With ester ylides 3a,b, the reaction affords hydroxyquinolines 8a,b and new stable phosphorus ylide 9, whereas with keto ylides 3c,d, quinolinones 12a,b, hydroxyindoles 10a,b and benzoazepines 14a,b are obtained. 1 reacts with allyl‐4, methyl‐5a and ethyltriphenylphosphonium bromides 5b in the presence of LiH to afford 2‐hydrophenyloxazolo[1,2‐a]‐ 4‐hydroxyquinoline (16) from the first reaction whereas alkoxyquinolines 21a,b and hydroxyazepines 22a,b are obtained from 5a,b.     

New Look into the Synthesis of Polyhalogenoarylphosphanes

The present study shows new aspects of the synthesis of polyhalogenoarylphosphanes. The sterically hindered anions Ph(R)P-Y^? (1a–c, Y = O, lone pair; R = Ph, Bu^t) have been used to show the complexity of the reaction between phosphorus nucleophiles and hexahalogenobenzenes or 9-bromofluorene (E3). The Ph(Bu^t)P-O^? (1a) anion reacts with hexachlorobenzene (E1), hexafluorobenzene (E2), or E3 to give Ph(R)P(O)X (4a–c, X = F, Cl, Br) with the release of the corresponding carbanion as a nucleofuge, followed by side reactions. In contrast, the lithium phosphides Ph(R)PLi (1b,c) react with hexahalogenobenzenes to give the corresponding diphosphanes 5a,b as the main product and traces of P-arylated products, i.e., Ph(R)P-C₆X₅ (10a,b, X = Cl, F). Unexpectedly, Ph(Bu^t)PLi (1b) reacts with an excess of 9-bromofluorene to give only halogenophosphane Ph(Bu^t)P-X.     

NC Palladacycles and C,C-chelating phosphorus ylide complexes: synthesis,X-ray characterization,and comparison of the catalytic activity in the Suzuki-Miyaura reaction

Six secondary amine palladacycles bearing monodentate ligands (1a, 2a), 1,2-bis(diphenylphosphino)ethane (dppe) and 1,3-bis(diphenylphosphino)propane (dppp) containing bridging and bidentate ligands (1b, 2b–d), and four C,C-type phosphorus ylide complexes containing thiourea (tu) (3a), phenyl isothiocyanate (4a), and bridging and terminal azide groups (5 and 5a) have been synthesized. Resulting complexes have been characterized by elemental analyses, IR, ¹H-, ¹³C{¹H}-, and ³¹P{¹H}-NMR spectroscopy with single crystal X-ray structure determination of 1a and 2a. The Pd in 1a and 2a occupies the center of a slightly distorted square planar environment formed by C_aryl, N_amine, N_pyridine, and Cl. The catalytic efficiency of complexes showed that in most cases, amine palladacycles display better catalytic activities than the phosphorus ylide Pd(II) complexes. Comparison between bidentate and bridging dppe complexes showed that dppe-bridged dimer 2d has higher catalytic activity than dppe bidentate complex.     

Reaction of 2-Thioxo-4-Thiazolidinones Toward Lawesson's Reagent,Phosphorus Pentasulfide,Dialkylaminophosphines, and Phosphorus Ylides

Abstract

2-Thioxo—3-allyl-4-thiazolidinone 1a reacts with Lawesson's reagent (LR, 2) to give the ethylenic product 5 through a coupling reaction along with the dithioxo compound 6. Coupling reaction products of types 8 and 9 are also produced upon reacting thiazolidinones 1 and with the appropriate tris(diallkylamino) phosphine reagent (3 a,b). Reaction of the thiazolidinone 1a with the ylidenetriphenylphosphorane reagents 4 a–c proceeds according to the Wittig mechanism yielding ethylenes 10a–c, respectively. Structural elucidations for the new products were based upon compatible analytical and spectroscopic measurements as well a confirmatory single crystal X-ray structure for 5.

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.     

THE BEHAVIOR OF N-PHENYLIMINOPHOSPHORANE TOWARDS o- AND p-QUINONES. NEW SYNTHESIS OF DIOXAZOLE AND OXADIAZOLE DERIVATIVES

ABSTRACT

N-Phenyliminophosphorane (1) reacts with 9,10-phenanthrenequinone (2a) to give the new products 2-phenylphenanthro[9,10-d][1,3,2]dioxazole (4a) and (10Z)-10-(phenylimino)-9(10H) phenanthrenone (4b). The reaction of 1 with 1,2-naphthoquinone (2b) afforded both the dioxazole derivative 5a and the known 2-anilino-naphthoquinone-1,4-anil (5b). On the other hand, 2,6-di-tert-butyl-2,3-diphenyl-2,3-dihydro-1,2,3-benzoxadiazole (6) was obtained from the reaction of (2c) with phosphinimine (1). Application of reagent 1 on 2d and 2e renders (6E)-2,3,4,5-tetrahalogeno-6-(phenylimino)-2,4-cyclohexadien-1-one 7a and 7b, respectively. Moreover, p-quinones (3a–3c) react with phosphinimine (1) to yield products 8, 9 and 10, respectively. Mechanisms accounting for the formation of the new products are discussed and the probable structures of the products are presented based on analytical and spectroscopic data.     

Zur Umsetzung des 3,4,5,6-Tetrahydro-6-hydroxy-4,4,6-trimethyl-1,3-thiazin-2-thions mit primären Aminen

Tetrahydro-6-hydroxy-4,4,6-trimethyl-1,3-thiazine-2-thione (1 a) reacts with methyl-, ethyl- and n-butylamine to the corresponding 1-alkyl-6-alkylaminotetrahydro-2(1H)-pyrimidinethione12 but withi-propylamine to tetrahydro-6-isopropylamino-1,3-thiazine-2-thione (6 d). On treatment withDCC,6 d is rearranged to dihydro-4-isopropylamino-2(1H)-pyridinethione (8 d), and 6-amino-tetrahydro-1,3-thiazinethione (6 a) to dihydro-4,4,6-trimethyl-2(1H)-pyrimidinethione (10 a). The reaction of 6-aminothiazinethiones6 a, d and 6-(4-morpholinyl)-thiazinethione13 resp., with methylamine leads to 1-methyl-6-methylamino-pyridinethione12 b. 1-Alkyl-6-alkylamino-tetrahydro-2(1H)-pyrimidinethiones (12) react at reflux temperature to dihydro-1-alkylpyrimidinethiones10. With methylamine only 6-methylamino-3,4,4,6-tetramethyl-1,3-thiazine-2-thione (6 f) is formed from tetrahydro-6-hydroxy-tetramethyl-1,3-thiazine-2-thione (1 b).     

Ruthenium(II) carbonyl complexes of P,P and P,O donor diphosphine ligands,Ph2P(CH2)nPPh2 and Ph2P(CH2)nP(O)Ph2, n = 2, 3 and their activities in catalytic transfer hydrogenation reactions

The polymeric precursor [RuCl₂(CO)₂]_n reacts with the ligands, P∩P (a, b) and P∩O (c, d), in 1:1 M ratio to generate six-coordinate complexes [RuCl₂(CO)₂(?²-P∩P)] (1a, 1b) and [RuCl₂(CO)₂(?²-P∩O)] (1c, 1d), where P∩P: Ph₂P(CH₂)_nPPh₂, n = 2(a), 3(b); P∩O: Ph₂P(CH₂)_nP(O)Ph₂, n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR, and NMR spectroscopy. 1a–1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75–290 h^?1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl₃ itself. Among 1a–1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogs (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b, and 1d decrease considerably, while 1c shows similar activity during the second run.     

REACTIONS OF URACILS, 181: REACTION OF 5-FORMYL-1,3-DIMETHYL-BARBITURIC ACID AND 5-FORMYL-1,3,6- TRIMETHYLURACIL WITH ETHOXYCARBONYL- METHYLENETRIPHENYLPHOSPHORANE

Abstract

Ethoxycarbonylmethylenetriphenylphosphorane (2) reacts with 5-formyl-1,3,6-trimethyluracil (1c) in the expected way to afford the acrylate 3c, while with 5-formyl-1,3-dimethylbarbituric acid (1b) a novel phosphorus ylide/phosphorane 4 is obtained (X-ray analysis). The temperature dependent NMR spectra and the mechanism of formation are discussed.     

Synthesis of new functionalized 5,5-dimethyl-1-pyrroline 1-oxides and their investigation as spin traps

The reactions of 5,5-dimethyl-3-oxo-1-pyrroline 1-oxide (3-oxo-DMPO, 1) with NH₂OH and N₂H₄ afforded oxime (2a) and hydrazone (2b), respectively. The reaction products were studied as spin traps for the short-lived radicals HO^·, Ph^·, PhCO₂ ^·, NC(Me₂)C^·, and NC(Me₂)CO^·. The nitroxides generated in the reactions of the above-mentioned short-lived radicals with nitrones 1 and 2a,b were characterized by ESR spectroscopy. Of these nitrones, oxime 2a is the most effective radical trap.     

Organophosphorus chemistry 30 [1]. The behavior of 4-hydroxycoumarin toward methylenetriphenylphosphoranes (Wittig Reagents) and alkyl phosphites

4-Hydroxycoumarin (1) reacted with Wittig reagents (2) to give 4-benzoylmethylcoumarin(5A) or [3-(4-hydroxycoumarinyl)]carbonylmethyl-enetriphenylphosphorane (6) depending upon the nature of the phosphorus ylide used. Dialkyl phosphonates (3a,b) and trialkyl phosphites (4a,b) converted 1 into the respective O-alkyl ethers (11a,b). The ground-state structure of 1 is discussed in the light of experimental results. Compatible elementary and spectroscopic results were gained for the new products. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:427–431, 1998     

Synthese und polarographisches Verhalten von 2H-Isoindol-4,7-dionen

Summary 2-Phenylthio-1,4-benzoquinone (1 a) reacts with azomethine ylide AY-A to give 2-methyl-5-phenylthio-2H-isoindole-4,7-dione (4 f). With 2-(N-methylanilino)-5-methyl-1,4-benzoquinone (1 b), the azomethine ylide AY-B undergoes cycloaddition to yield an inseparable mixture of 5a-methyl-8-(N-methylanilino)-2,3,5,5a,9a,9b-hexahydro-pyrrolo[2,1-a]1H-isoindole-6,9-dione (5 bI) and 9a-methyl-7-(N-methylanilino)-2,3,5,5a,9a,9b-hexahydropyrrolo[2,1-a]1H-isoindole-6,9-dione (5 bII). The structures of5 bI and5 bII were established on basis of two-dimensional-NMR-techniques. The mechanism of the cycloaddition of azomethine ylides to 1,4-quinones was studied on basis of cyclovoltammetric investigations. To determine the electron affinity of the isoindoledione derivatives4 a–f and5 a–b the peak potentials were measured by differential pulse polarography (DPP).

     

Oxygen- versus carbon-coordination of the alpha-stabilized phosphorus ylide Ph<Subscript>3</Subscript>P=C(H)R in palladacycles bearing secondary amines

The ortho-metalated complex [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) was prepared by refluxing in benzene equimolecular amounts of Pd(OAc)₂ and secondary benzylamine [a, EtNHCH₂Ph; b, t-BuNHCH₂Ph followed by addition of excess NaCl. The reaction of the complexes [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) with a stoichiometric amount of Ph₃P=C(H)COC₆H₄-4-Z (Z = Br, Ph) (ZBPPY) (1:1 molar ratio), in THF at low temperature, gives the cationic derivatives [Pd(OC(Z-4-C₆H₄C=CHPPh₃){κ ² (C,N)-[C₆H₄CH₂NRR′(Y)}] (5a–9a, 4b–6b, and 4b′–6b′), in which the ylide ligand is O-coordinated to the Pd(II) center and trans to the ortho-metalated C(6)H(4) group, in an “end-on carbonyl”. Ortho-metallation, ylide O-coordination, and C-coordination in complexes (5a–9a, 4b–6b, and 4b′–6b′) were characterized by elemental analysis as well as various spectroscopic techniques.     

Ozonolyse von Olefinen,III: Säurekatalysierte Ozonolyse von 3-Hexen-1,6-und 2-Penten-1,5-dicarbonylderivaten

Summary The ozonolysis of mono-unsaturated compounds containing the structural element =CH-CH₂-R [R=COOH, COOCH₃, CH(OCH₃)₂] was investigated. Reductive ozonolysis of (E)-3-hexene-1,6-dioic acid gives methyl 3,3-dimethoxypropanoate (2), whereas ozonolysis of dimethyl (E)-3-hexene-1,6-dioate (1a) and (Z)-1,1,6,6-tetramethoxy-3-hexene (1b) in a methanolic solution of HCl leads to a mixture of2, dimethyl malonate (3 a) and 1,1,3,3-tetramethoxypropane (3 b). The homologuos derivatives, dimethyl glutaconate (4 a) and 1,1,5,5-tetramethoxy-2-pentene (4 b), were ozonized to give mixtures of2, 3, dimethyl oxalate (5), methyl 2,2-dimethoxyacetate (6 a), and 1,1,2,2-tetramethoxyethane (6 b). The ratios of the various reaction products were determined by gas chromatography. In each case the formation of the bifunctional derivatives2 and6 a was favoured.

     

Facile Synthesis of Some New Pyrazole-Based 2-Thioxo-4-thiazolidinone

5-Ethoxymethylene-2-thioxo-4-thiazolidinone (1) reacts with hydrazine hydrate at room temperature to afford 5-(hydrazinylmethylene)-2-thioxo-4-thiazolidinone (3). Compound 3 condensed with different aromatic aldehydes 6a–d in ethanol in the presence of a few drops of piperidine to give the corresponding Schiff’s bases 7a–d. On the other hand, compound 3 reacts with o-hydroxybenzaldehyde derivatives 8a and 8b in refluxing ethanol catalyzed by a few drops of piperidine to yield 1H-inadzolyl-2-thioxo-4-thiazolidinones 9a and 9b. Reaction of compound 3 with α-ketoesters 10a and 10b or α-diketones 10c–e in refluxing glacial acetic acid furnished the pyrazolyl-2-thioxo-4-thiazolidinone derivatives 11a–e. Also, compound 3 reacts with some different enaminones 12a–f in refluxing glacial acetic acid to afford the new pyrazolyl-2-thioxo-4-thiazolidinone derivatives 13a–f. Pyrazoles 15a–d was obtained via reaction of compound 3 with chalcones 14a–d in dimethylformamide (DMF). The structures of all the newly synthesized products were confirmed on the basis of their elemental and spectral data, and a plausible mechanism has been postulated to account for their formation.     

Über die 2-(1,2,3,4-Tetrahydro-4,4,6-trimethyl-2-thioxopyrimidin-1)-benzoesäure und das 2,3,4,4a-Tetrahydro-3,3,4a-trimethyl-1-thioxo-1H, 6H—pyrimido[1,6-a][3,1]-benzoxazin-6-on Über Heterocyclen, 55. Mitt.

Dimethyloxobutylisothiocyanate1 reacts with anthranilic acid to a mixture of much pyrimidobenzoxazine5 a and less tetrahydrothioxopyrimidinebenzoic acid3 a (and tautom.4 a resp.). By treatment with methanolic KOH solution5 a is converted into3 a, 4 a. At refluxing temperature3 a, 4 a, and5 a resp., are rearranged inDMF into thioxopyridineanthranilic acid7 a, thioxopyridineanthranilic dimethylamide7 d and dimethylaminodihydro-2(1H)-pyridinethione8. Also pyridineanthranilates7b, c and pyridineanthranilic nitrile12 are formed from pyrimidinebenzoic esters3 b, 4 b, 3 c, 4 c and pyrimidinebenzoic nitrile10, 11 resp., by boiling inDMF. The reaction of1 with methyl anthranilate leads to7 b and triazapentaphene9. o-Aminobenzoic nitrile HCl reacts with1 to pyrimidinequinazoline5 b.     

THE NOVEL MACROCYCLIC AND LINEAR-CHAIN THIOETHERS FROM PERCHLOROBUTADIENE AND DITHIOLES

Compounds 3a–c, 4a, b, 5a–c, and 6a, c were obtained from the reactions of perchlorobutadiene (1) with 1,4-butanedithiol (2a), 1,5-pentanethiol (2b), and 2.2′-(ethlene-dioxyl)diethanethiol (2c) in ethanol in the presence of sodium hydroxide. Compounds 7a, b were obtained from the reactions of thioethers 3a, b with m-chlorperbenzoic acid in CHCl ₃ .     

Cyclisierung von Oligomeren des Malodinitrils mit Amidinen Synthesen mit Nitrilen, 55. Mitt

Condensation of formamidine-acetate with dimeric malononitrile (1 a) leads to 2,4-diamino-3,5-pyridine-dicarbonitrile (3 a), with acetamidine-HCl the methyl derivative3 b is obtained. Reaction of the codimer of malononitrile and methyl cyanoacetate (1 b) with formamidine yields the aminopyridine3 c, while acetamidine and benzamidine, resp. with1 b react to the 1,4-dihydro-4-pyrimidinylidene-methyl-cyanoacetates4 a-b.

     

Zur Synthese kondensierter Heterocyclen aus Malonsäurederivaten

Zusammenfassung Die Reaktion der 2-alkylsubstit. Benzoxazole (1 a, 1 c), Benzothiazole (1 b, 1 d) und des Benzoselenazols (1 e) mit Malonsäuretrichlorphenylestern (2 a, b) führt in Abhängigkeit von der Art des Alkylrestes zu den kondensierten Hydroxypyridonen3 oder deren Hydroxypyronoderivaten4. In analoger Weise reagiert 2,5-Dimethyl-thiadiazol (5) mit2 a zu einem Pyrono-thiadiazolo-pyridon (7).

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Syntheses of heterocycles, CLIX: Syntheses of fused heterocycles from malonic acid derivatives

The reaction of 2-substituted benzoxazoles (1 a, 1 c), benzothiazoles (1 b, 1 d) and benzoselenazole (1 e) with 2,4,6-trichlorophenyl malonates (2 a, b) gives—depending on the nature of the alkyl substituent—the fused hydroxypyridones3 or their hydroxypyrono derivatives. 2,5-Dimethyl-thiadiazol5 reacts in the same way with2 a yielding the pyrono-thiadiazolopyridon7.

     

ORGANOPHOSPHORUS COMPOUNDS,XXX

Abstract

Fluoroenylidenetriphenylphosphorane (1a) reacts with maleic and phthalic anhydrides to give lactones 2a and 3, respectively. The same reagent (1a) extrudes sulphur from thiophthalic anhydride yielding the spiro-1,3-indandione derivative 4. The infrared and mass spectra of the new products are discussed.