Ionic Thiourea Organocatalysis of the Morita–Baylis–Hillman Reaction

2016 ◽  
Vol 69 (7) ◽  
pp. 759 ◽  
Author(s):  
Trevor McGrath ◽  
Katherine N. Robertson ◽  
Jason D. Masuda ◽  
Jason A. C. Clyburne ◽  
Robert D. Singer
Keyword(s):  
Ionic Liquid ◽  
Microwave Heating ◽  
Reaction Times ◽  
Crystallographic Analysis ◽  
Acetone Molecule ◽  
Catalyst Recycling ◽  
Co Catalyst ◽  
X Ray ◽  
Hydrogen Bonded

An ionic thiourea based organocatalyst has been shown to promote a 1,4-diazabicyclo[2.2.2]octane, (DABCO) catalysed Morita-Baylis-Hillman reaction between benzaldehyde and cyclohex-2-en-1-one. The ionic thiourea catalyst was easily prepared from a pyrrolidinium salt containing an arylamine moiety and 3,5-di(trifluoromethyl)phenylisothiocyanate. X-ray crystallographic analysis of the ionic thiourea catalyst shows an acetone molecule doubly hydrogen bonded to the Lewis acidic thiourea N-H protons. Entrainment of the ionic thiourea co-catalyst in the ionic liquid N-butyl-N-methylpyrrolidinium bistriflimide, [BMPyr][N(Tf)2], facilitates catalyst recycling and affords very good yields with reaction times reduced through use of microwave heating.

scholarly journals 10H-Pyrazino[2,3-b][1,4]benzotellurazine, a Novel Tellurium-Containing Heterocyclic System

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Diamond S. Smith ◽  
Dallas N. Alexis ◽  
Frank R. Fronczek ◽  
Thomas Junk
Keyword(s):  
Title Compound ◽  
Heterocyclic System ◽  
Crystallographic Analysis ◽  
Supramolecular Assemblies ◽  
Methyl Derivative ◽  
X Ray ◽  
Hydrogen Bonded

Condensation of 2,3-dichloropyrazine with 2-aminobenzenetellurole and 2-amino-5-methylbenzenetellurole, generated in situ by reduction of the corresponding ditellurides, resulted in the formation of novel 10H-pyrazino[2,3-b][1,4]benzotellurazine and its 7-methyl derivative. The products were purified via their well-crystallized 5,5-dibromo derivatives. X-ray crystallographic analysis of the title compound indicates that it has a pronounced V-shape and forms hydrogen-bonded dimers. Te, N-containing heterocycles have the potential of offering access to supramolecular assemblies.

scholarly journals Ferrocene-Containing Ionic Liquid Supported on Silica Nanospheres (SiO2@Imid-Cl@Fc) as a Mild and Efficient Heterogeneous Catalyst for the Synthesis of Pyrano[3,2-b]Pyran Derivatives Under Ultrasound Irradiation

2018 ◽  
Vol 42 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Reza Teimuri-Mofrad ◽  
Somayeh Esmati ◽  
Masoumeh Rabiei ◽  
Mahdi Gholamhosseini-Nazari
Keyword(s):  
Ionic Liquid ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Significant Loss ◽  
One Pot ◽  
X Ray ◽  
Three Component Reaction

A novel heterogeneous silica nanosphere-supported ferrocene-containing ionic liquid catalyst (SiO2@Imid-Cl@Fc) was designed and synthesised and was systematically characterised by Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis. The catalytic activity of the SiO2@Imid-Cl@Fc catalyst was tested in a one-pot, three-component reaction of malononitrile and kojic acid with 15 aromatic aldehydes at room temperature under ultrasound irradiation. The products were pyrano[3,2-b]pyran derivatives, four of which are new. The catalyst exhibited good catalytic performance over short reaction times (15–20 min) and could be recycled at least five times without significant loss of activity.

Preparation of Magnetic Ionic Liquids Composed of Hybrid-Type Anions

2012 ◽  
Vol 65 (11) ◽  
pp. 1557 ◽  
Author(s):  
Yumiko Takagi ◽  
Yoriko Kusunoki ◽  
Yukihiro Yoshida ◽  
Hirofusa Tanaka ◽  
Gunzi Saito ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Magnetic Property ◽  
Ionic Liquids ◽  
Crystallographic Analysis ◽  
The Other ◽  
X Ray ◽  
Magnetic Ionic Liquids ◽  
Hybrid Type ◽  
Magnetic Ionic Liquid ◽  
Chloride Hydrate

1-Ethyl-3-methylimidazolium ethylsulfate ([C2mim][EtSO4]) was mixed with iron(III) chloride·6H2O to give a magnetic ionic liquid composed of the hybrid-type anion, [C2mim][FeCl3·EtSO4], which showed a slightly different magnetic property than [C2mim][FeCl4]. On the other hand, reaction of [C2mim][EtSO4] with cobalt(II) chloride hydrate formed [C2mim]2[CoIICl4], the structure of which was characterised by X-ray crystallographic analysis.

X-Ray crystallographic analysis of D,L-[Fe2{SCH2CH(CH2OH)S}(CO)6] reveals a hydrogen-bonded cyclic hexamer with ordered optical centres

2001 ◽  
pp. 3551-3552 ◽  
Author(s):  
Mathieu Razavet ◽  
Alban Le Cloirec ◽  
Sian C. Davies ◽  
David L. Hughes ◽  
Christopher J. Pickett
Keyword(s):  
Crystallographic Analysis ◽  
X Ray ◽  
Hydrogen Bonded

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

Self-Recognizing π-π Stacking Interactions Designed for the Generation of Ultrastable Mesoporous Hydrogen-Bonded Organic Frameworks

2019 ◽  
Author(s):  
KAIKAI MA ◽  
Peng Li ◽  
John Xin ◽  
Yongwei Chen ◽  
Zhijie Chen ◽  
...  
Keyword(s):  
Pore Size ◽  
Fiber Composite ◽  
Aqueous Media ◽  
Stacking Interactions ◽  
Mustard Gas ◽  
X Ray Diffraction ◽  
X Ray ◽  
Expansion Strategy ◽  
Π Stacking ◽  
Hydrogen Bonded

Creating crystalline porous materials with large pores is typically challenging due to undesired interpen-etration, staggered stacking, or weakened framework stability. Here, we report a pore size expansion strategy by self-recognizing π-π stacking interactions in a series of two-dimensional (2D) hydrogen–bonded organic frameworks (HOFs), HOF-10x (x=0,1,2), self-assembled from pyrene-based tectons with systematic elongation of π-conjugated molecular arms. This strategy successfully avoids interpene-tration or staggered stacking and expands the pore size of HOF materials to access mesoporous HOF-102, which features a surface area of ~ 2,500 m2/g and the largest pore volume (1.3 cm3/g) to date among all reported HOFs. More importantly, HOF-102 shows significantly enhanced thermal and chemical stability as evidenced by powder x-ray diffraction and N2 isotherms after treatments in chal-lenging conditions. Such stability enables the adsorption of dyes and cytochrome c from aqueous media by HOF-102 and affords a processible HOF-102/fiber composite for the efficient photochemical detox-ification of a mustard gas simulant.

Purification, crystallization and X-ray crystallographic analysis of ATPase domain in transcription regulator DmpR

2019 ◽  
Vol 7 (2) ◽  
pp. 52-55
Author(s):  
Su-Jin Lee ◽  
In-Young Baek ◽  
Yan An ◽  
Woo-Chan Ahn ◽  
Kwang-Hyun Park ◽  
...  
Keyword(s):  
Crystallographic Analysis ◽  
Atpase Domain ◽  
X Ray ◽  
Transcription Regulator

Purification, crystallization and X-ray crystallographic analysis of methylglyoxal reductase Gre2 from Candida albicans

2019 ◽  
Vol 7 (2) ◽  
pp. 42-46 ◽  
Author(s):  
Giang Thu Nguyen ◽  
Shinae Kim ◽  
Hang-Suk Chun ◽  
Woo-Keun Kim ◽  
Jeong Ho Chang
Keyword(s):  
Candida Albicans ◽  
Crystallographic Analysis ◽  
X Ray

Preparation and Characterization of a Novel Room Temperature Dicationic Ionic Liquid and its Application in the Synthesis of Xanthenediones Under Solvent-Free Conditions

2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Reaction Times ◽  
Significant Loss ◽  
Solvent Free ◽  
Acidity Function ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Hammett Acidity Function ◽  
Dicationic Ionic Liquid

Aim and Objective: In the present work, 1, 1’-sulfinyldiethylammonium bis (hydrogen sulfate) as a novel room temperature dicationic ionic liquid was synthesized and used as a catalyst for xanthenediones synthesis. Material and Method: The dicationic ionic liquid has been synthesized using ethylamine and thionyl chloride as precursors. Then, by the reaction of [(EtNH2)2SO]Cl2 with H2SO4, [(EtNH2)2SO][HSO4]2 was prepared and after that, it was characterized by FT-IR, 1H NMR, 13C NMR as well as Hammett acidity function. This dicationic ionic liquid was used as a catalyst for the synthesis of xanthenediones via condensation of structurally diverse aldehydes and dimedone under solvent-free conditions. The progress of the reaction was monitored by thin layer chromatography (ethyl acetate/n-hexane = 3/7). Results: An efficient solvent-free method for the synthesis of xanthenediones has been developed in the presence of [(EtNH2)2SO][HSO4]2 as a powerful catalyst with high to excellent yields, and short reaction times. Additionally, recycling studies have demonstrated that the dicationic ionic liquid can be readily recovered and reused at least four times without significant loss of its catalytic activity. Conclusion: This new dicationic ionic liquid can act as a highly efficient catalyst for xanthenediones synthesis under solvent-free conditions.

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