Reaction of Phosphorus Compounds. V. Resonance-stabilized α-Halomethylenephosphoranes

Speziale, A. J.; Ratts, K. W.

doi:10.1021/jo01037a046

Cited by 56 publications

(19 citation statements)

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“…[31] A typical synthesis was carried out as follows. Thiourea (7.61 g, 100 mmol) and alkenyl bromide (20 mmol) were added to ethanol (300 mL) in a two-neck flask equipped with a reflux condenser.…”

Section: Methodsmentioning

confidence: 99%

Detailed Structural Examinations of Covalently Immobilized Gold Nanoparticles onto Hydrogen‐Terminated Silicon Surfaces

Yamanoi

Shirahata

Yonezawa

et al. 2005

Chemistry A European J

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The modification of flat semiconductor surfaces with nanoscale materials has been the subject of considerable interest. This paper provides detailed structural examinations of gold nanoparticles covalently immobilized onto hydrogen-terminated silicon surfaces by a convenient thermal hydrosilylation to form Si-C bonds. Gold nanoparticles stabilized by omega-alkene-1-thiols with different alkyl chain lengths (C3, C6, and C11), with average diameters of 2-3 nm and a narrow size distribution were used. The thermal hydrosilylation reactions of these nanoparticles with hydrogen-terminated Si(111) surfaces were carried out in toluene at various conditions under N2. The obtained modified surfaces were observed by high-resolution scanning electron microscopy (HR-SEM). The obtained images indicate considerable changes in morphology with reaction time, reaction temperature, as well as the length of the stabilizing omega-alkene-1-thiol molecules. These surfaces are stable and can be stored under ambient conditions for several weeks without measurable decomposition. It was also found that the aggregation of immobilized particles on a silicon surface occurred at high temperature (> 100 degrees C). Precise XPS measurements of modified surfaces were carried out by using a Au-S ligand-exchange technique. The spectrum clearly showed the existence of Si-C bonds. Cross-sectional HR-TEM images also directly indicate that the particles were covalently attached to the silicon surface through Si-C bonds.

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Section: Methodsmentioning

confidence: 99%

Detailed Structural Examinations of Covalently Immobilized Gold Nanoparticles onto Hydrogen‐Terminated Silicon Surfaces

Yamanoi

Shirahata

Yonezawa

et al. 2005

Chemistry A European J

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“…and extracted with ethyl acetate (3 x 10 mL). The organic solubles were dried (NalS04) and evaporated to give 14 3-Chloro-4-(dichloro,nefhyl)-5-hydro.~y-2(5H)Tfiirc~nut1e (16) The acid 14 (0.79 g, 2.9 mmol) and KHC03 (0.581 g, 5.8 mmol) were dissolved in H1O (25 mL) and heated for 3 h at 50°C under Nl. The reaction mixture was thcn cooled (to 20°C) and extracted with ethyl acetate (3 x 20 mL).…”

Section: Methyl 3-(dichlorot~~c~tl1yi)44-dichloro~rofot1ee (9)mentioning

confidence: 99%

Synthesis of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone, a potent mutagen

Padmapriya¹,

Just²,

Lewis³

1985

Can. J. Chem.

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Starting from tetrachloroacetone 1 and (carbomethoxymethylene)triphenylphosphorane 4, the title compound 16 was prepared in five steps in 44% yield. Spectroscopic and chromatographic data indicated that this material was identical to a potent mutagen isolated from kraft pulp chlorination effluent. Various mutant Salmonellatyphimurium strains (TA 98, 100, and 1537) behaved similarly when incubated with either 16 or the isolated mutagen.

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“…En fait, la fluoruration tlectrophile de 1 a l'aide du fluorure de perchloryle n'a pas Ct C possible et les tentatives de dkplacement par la triphknylphosphine de l'atome de chlore du chlorofluoroacktonitrile ont Cgalement Cchoue. Speziale [4] avait deja rapport6 l'absence de reaction entre le chlorofluoroacetate d'ethyle et la triphknylphosphine (ou m&me la tributylphosphine). Nous avons nkanmoins form6 2 in situ en recourant a la technique de Seyferth [5] pour la formation d'ylures halogknomethylideniques.…”

Section: Discussionunclassified

“…Les ylures iodks du type Ph,P=C(I)COR sont reputes de preparation difficile [4] [lo] ou non rkactifs vis-a-vis des aldehydes [ l l ] . L'ylure 5, facilement obtenu en traitant le chlorhydrate de 1 par de l'iode alo", en presence de triethylamine (2,2 equivalents [2].…”

Section: Discussionunclassified

Cyanohalogénométhylidènetriphénylphosphoranes. Note de Laboratoire

Tronchet

Martin

1979

Helvetica Chimica Acta

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Cyanohalogenomethylidenetriphenylphosphoranes SummaryIodo-, bromo and chlorocyanomethylidenetriphenylphosphoranes are described as well as a procedure for the in situ generation of cyanofluoromethylidenetriphenylphosphorane. These ylides are reactive towards aldehydosugars. Des quatre cyanohalogenomtthylidt.netriphCny1phosphoranes Ph,P =C(Hal)CN, seul le derive brome 4 avait t t C partiellement dkcrit [2]. Nous rapportons la preparation en bon rendement et l'isolement i l'etat pur de ses analogues chlore 3 et iode 5, de m&me que la formation in situ du derive fluore 2. Les ylures 2-5 reagissent avec les aldehydosucres A pour fournir les enoses attendus B [I], polyelectrophiles, intermediaires potentiels pour la synthi.se [I] [3].

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Reaction of Phosphorus Compounds. V. Resonance-stabilized α-Halomethylenephosphoranes

Cited by 56 publications

References 0 publications

Detailed Structural Examinations of Covalently Immobilized Gold Nanoparticles onto Hydrogen‐Terminated Silicon Surfaces

Detailed Structural Examinations of Covalently Immobilized Gold Nanoparticles onto Hydrogen‐Terminated Silicon Surfaces

Synthesis of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone, a potent mutagen

Cyanohalogénométhylidènetriphénylphosphoranes. Note de Laboratoire

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