Behaviour of iprit carbonate analogues in solventless reactions

RSC Advances ◽  
2014 ◽  
Vol 4 (59) ◽  
pp. 31071-31078 ◽  
Author(s):  
F. Arico' ◽  
S. Evaristo ◽  
P. Tundo
Keyword(s):  
Nucleophilic Substitution ◽  
Atmospheric Pressure ◽  
Catalytic Amount ◽  
Solventless Reactions

Sulfur iprit carbonate analogues showed to undergo nucleophilic substitution with several substrates in neat conditions at atmospheric pressure, in the presence and in the absence of a catalytic amount of base.

Silicon cation and anion chemistry in a fuel-rich, methane–oxygen flame

1992 ◽  
Vol 70 (4) ◽  
pp. 1069-1081 ◽  
Author(s):  
J. Hugh Horton ◽  
John M. Goodings
Keyword(s):  
Nucleophilic Substitution ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Orthosilicic Acid ◽  
Ion Chemistry ◽  
Silicon Ions ◽  
Normal Carbon ◽  
Silicon Chemistry ◽  
Three Body ◽  
Oxygen Flame

Silicon cations and anions in a fuel-rich, premixed, methane–oxygen flame at atmospheric pressure doped with 0.01 mol% of trimethylsilane were observed by sampling the flame through a nozzle into a mass spectrometer. Twelve cations were observed which can be grouped into five series: SiOH+.nH2O (n = 0–2); SiOCH3+.nH2O (n = 0–2); Si(OH)3+.nH2O (n = 0–2); cations by nucleophilic substitution (e.g., Si(OH)(CH3)2(H2O)+); and carbonaceous aromatic cations (c-HSiCH=CH+ and c-HSiCH=CCH3+). Similarly, five anions were observed as members of two series: HxSiO3− (x = 0, 1) and HxSiO4− (x = 1–3). The chemical ionization reactions for the formation of these ions are discussed in detail, including proton transfer and also methyl cation transfer, three-body addition, nucleophilic substitution (SN2) of both the ions themselves and also their neutral silicon precursors, and H-atom abstraction reactions. The neutral silicon chemistry in the flame is dominated by SiO, but evidence was obtained from both the cation and the anion chemistry for the presence of HSiO(OH), silanoic acid; SiO(OH)2, metasilicic acid; and Si(OH)4, orthosilicic acid. The silicon ion chemistry differs markedly from the normal carbon ion chemistry that occurs naturally in the undoped methane–oxygen flame; the silicon ions show a strong tendency towards Si—O bond formation. Consideration is given to the probable structures of the various silicon cations and anions observed.

A Practical Synthesis of Ammonia from Nitrogen Gas, Samarium Diiodide and Water Catalyzed by a Molybdenum–PCP Pincer Complex

Synthesis ◽  
2019 ◽  
Vol 51 (20) ◽  
pp. 3792-3795 ◽  
Author(s):  
Yuya Ashida ◽  
Shoichi Kondo ◽  
Kazuya Arashiba ◽  
Takamasa Kikuchi ◽  
Kazunari Nakajima ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Catalytic Amount ◽  
Practical Method ◽  
Samarium Diiodide ◽  
Ambient Conditions ◽  
Nitrogen Gas ◽  
Pincer Complex ◽  
Proton Source ◽  
Practical Synthesis ◽  
Pcp Pincer

A practical method for ammonia synthesis is described. The reaction of atmospheric pressure of nitrogen gas with samarium diiodide as a reducing reagent and water as a proton source in the presence of a catalytic amount of a molybdenum trichloride complex bearing a PCP [1,3-bis(di-tert-butylphosphinomethyl)benzimidazol-2-ylidene]-type pincer ligand occurs under ambient conditions to afford ammonium sulfate after treatment with sulfuric acid.

scholarly journals Ru-Catalyzed Carbonylative Murai Reaction: Directed C3-Acylation of Biomass-Derived 2-Formyl Heteroaromatics

2019 ◽  
Author(s):  
Roberto Sala ◽  
Fares Roudesly ◽  
Luis F. Veiros ◽  
Gianluigi Broggini ◽  
Julie Oble ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Catalytic Amount ◽  
Catalytic Cycle ◽  
Acylation Reaction ◽  
Dft Computations

<p>We describe here the carbonylative Murai reaction applied to 2-formylfurans, 2-formylpyrrols and 2-formylthiophenes. Thanks to the installation of removable imine directing groups, this acylation reaction takes place regioselectively at C3 position of the heterocyclopentadienes. It can be achieved by treating the two reaction partners with a catalytic amount of Ru<sub>3</sub>(CO)<sub>12</sub>, in toluene at 120-150 °C, after CO bubbling, at atmospheric pressure. DFT computations of the full catalytic cycle help in deciphering the mechanism of this transformation, and to rationalize the different behaviors depending on the nature of imine directing groups.</p>

scholarly journals Ru-Catalyzed Carbonylative Murai Reaction: Directed C3-Acylation of Biomass-Derived 2-Formyl Heteroaromatics

2019 ◽  
Author(s):  
Roberto Sala ◽  
Fares Roudesly ◽  
Luis F. Veiros ◽  
Gianluigi Broggini ◽  
Julie Oble ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Catalytic Amount ◽  
Catalytic Cycle ◽  
Acylation Reaction ◽  
Dft Computations

<p>We describe here the carbonylative Murai reaction applied to 2-formylfurans, 2-formylpyrrols and 2-formylthiophenes. Thanks to the installation of removable imine directing groups, this acylation reaction takes place regioselectively at C3 position of the heterocyclopentadienes. It can be achieved by treating the two reaction partners with a catalytic amount of Ru<sub>3</sub>(CO)<sub>12</sub>, in toluene at 120-150 °C, after CO bubbling, at atmospheric pressure. DFT computations of the full catalytic cycle help in deciphering the mechanism of this transformation, and to rationalize the different behaviors depending on the nature of imine directing groups.</p>

scholarly journals Mustard carbonate analogues

2016 ◽  
Vol 88 (1-2) ◽  
pp. 3-16 ◽  
Author(s):  
Fabio Aricò ◽  
Pietro Tundo
Keyword(s):  
Atmospheric Pressure ◽  
Nitrogen Mustard ◽  
Catalytic Amount ◽  
Mustard Gas ◽  
New Class ◽  
New Family ◽  
Dialkyl Carbonates ◽  
Mechanism And Kinetics ◽  
Lower Temperature ◽  
Membered Heterocycle

AbstractSulfur and nitrogen (half-)mustard carbonate analogues are a new class of compounds, easily synthesized by methoxycarbonylation reaction of the parent alcohols with dialkyl carbonates. In this work, their reactivity as novel, green electrophiles is reported. Reactions have been conducted in autoclave conditions at high temperature (180°C), under pressure and in absence of any base, as well as, in neat at atmospheric pressure, lower temperature (150°C) and in the presence of a catalytic amount of a base. Several nucleophiles have been investigated resulting, in some cases, in unexpected compounds, i.e., six-membered heterocycle piperidine. Reaction mechanism and kinetics have been studied confirming that these compounds retain the anchimeric effect of their mustard gas analogues, without being toxic. Noteworthy, a symmetrical nitrogen mustard carbonate has also been employed as reagent in the preparation of a new family of macrocycles i.e., azacrowns, before not easily accessible.

Efficient synthesis of quinazoline-2,4(1H,3H)-diones from CO2 catalyzed by N-heterocyclic carbene at atmospheric pressure

RSC Advances ◽  
2015 ◽  
Vol 5 (7) ◽  
pp. 5032-5037 ◽  
Author(s):  
Yunqing Xiao ◽  
Xianqiang Kong ◽  
Zhicheng Xu ◽  
Changsheng Cao ◽  
Guangsheng Pang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Pressure ◽  
Catalytic Amount ◽  
Efficient Synthesis

Under atmospheric pressure, quinazoline-2,4(1H,3H)-diones were obtained from the reaction of 2-aminobenzonitriles with carbon dioxide (0.1 MPa) with a catalytic amount of N-heterocyclic carbene in DMSO.

A High-Voltage Terminal for a Field-Emission Gun

1972 ◽  
Vol 30 ◽  
pp. 428-429
Author(s):  
N. F. Ziegler
Keyword(s):  
Field Emission ◽  
High Voltage ◽  
Atmospheric Pressure ◽  
Power Supplies ◽  
High Coherence

A high-voltage terminal has been constructed for housing the various power supplies and metering circuits required by the field-emission gun (described elsewhere in these Proceedings) for the high-coherence microscope. The terminal is cylindrical in shape having a diameter of 14 inches and a length of 24 inches. It is completely enclosed by an aluminum housing filled with Freon-12 gas at essentially atmospheric pressure. The potential of the terminal relative to ground is, of course, equal to the accelerating potential of the microscope, which in the present case, is 150 kilovolts maximum.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

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