scholarly journals (C7H6NS)2[Nb6Cl18]·2C4H8O: first niobium cluster with an N,S-heterocyclic cation

IUCrData ◽  
2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Eric Sperlich ◽  
Martin Köckerling
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Room Temperature ◽  
High Yield ◽  
Cluster Compound ◽  
One Pot ◽  
Cluster Precursor ◽  
Acidic Proton ◽  
Very High

The title compound bis(benzothiazolium) dodeca-μ-chlorido-hexachlorido-octahedro-hexaniobium(12 Nb—Nb) tetrahydrofuran disolvate, (C7H6NS)2[Nb6Cl18]·2C4H8O or (HBTh)2[Nb6Cl18]·2THF, is the first known niobium cluster compound to contain an N,S-heterocyclic cation. The synthesis takes place within a few hours as an one-pot reaction at room temperature of the cluster precursor compound [Nb6Cl14(H2O)4]·4H2O with SOCl2 in the presence of BTh (benzothiazole) in very high yield. The stabilization of the acidic proton of the cation is achieved by the use of tetrahydrofuran as a co-solvent and by the formation of hydrogen bonds.

[Nb6Cl12(HIm)6](OAc)2·3MeOH – a hydrogen-bonded network of niobium cluster cations, acetate anions and methanol molecules

2019 ◽  
Vol 74 (10) ◽  
pp. 751-755
Author(s):  
Eric Sperlich ◽  
Martin Köckerling
Keyword(s):  
Hydrogen Bonds ◽  
Acetic Anhydride ◽  
Title Compound ◽  
Cluster Compound ◽  
Dehydration Reaction ◽  
Coulomb Interactions ◽  
One Pot ◽  
Cluster Precursor ◽  
Additional Hydrogen ◽  
Hydrogen Bonded

AbstractThe new cluster compound [Nb6Cl12(HIm)6](OAc)2 · 3MeOH represents the first example of network compounds consisting of hexanuclear niobium cluster cations and acetate anions, which are connected though hydrogen bonds (besides Coulomb interactions). Hydrogen-bonded cation-anion pairs form chains, which are further extended to sheets by additional hydrogen bonds to co-crystallized methanol molecules. The synthesis of the title compound is based on a one-pot dehydration reaction of the cluster precursor [Nb6Cl14(H2O)4] · 4H2O with acetic anhydride in the presence of imidazole at T = 40°C.

2-[Anilino(diphenylphosphoryl)methyl]phenol from a three-component Kabachnik–Fields reaction

2013 ◽  
Vol 69 (9) ◽  
pp. 1070-1072 ◽  
Author(s):  
Ming-Shu Wu ◽  
Qing-Qin Feng ◽  
Gao-Nan Li ◽  
De-Hui Wan
Keyword(s):  
Hydrogen Bonds ◽  
Hydroxy Group ◽  
Title Compound ◽  
Room Temperature ◽  
High Yield ◽  
Diphenylphosphine Oxide ◽  
One Dimensional ◽  
Compound C ◽  
Tetrahedral Environment ◽  
Racemic Crystals

The title compound, C25H22NO2P, was synthesized in high yield by a three-component Kabachnik–Fields reaction of diphenylphosphine oxide, salicylaldehyde and aniline in dry toluene at room temperature. It precipitates as racemic crystals, in which strong hydrogen bonds between the hydroxy group and the P=O group of a neighbouring molecule form one-dimensional heterochiral chains along the crystallographicaaxis, with an O...O separation of 2.568 (2) Å. The pseudo-tetrahedral environment of the P atom is distorted, with O—P—C bond angles significantly larger than the C—P—C angles.

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Abdullah Mohamed Asiri ◽  
Afaf Mohamed Abdel Hameed ◽  
Reham R. Awed ◽  
Kamal Usef Sadek
Keyword(s):  
Ambient Temperature ◽  
Environmental Pollution ◽  
Ammonium Nitrate ◽  
Room Temperature ◽  
Catalytic Amount ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Work Up ◽  
Cerium Iv Ammonium Nitrate

AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.

Visible Light-Promoted C–C Bond Formation from Hydroxyaryls in Water

2019 ◽  
Vol 72 (12) ◽  
pp. 978 ◽  
Author(s):  
Dafne Saporito ◽  
Sergio A. Rodriguez ◽  
Maria T. Baumgartner
Keyword(s):  
Visible Light ◽  
Bond Formation ◽  
High Yield ◽  
Reaction Yield ◽  
Halogen Lamp ◽  
One Pot ◽  
Direct Arylation ◽  
Photoinduced Reactions ◽  
Optical Applications ◽  
Very High

An eco-friendly and direct arylation of hydroxyaryls in water using photoinduced reactions with different substrates (1-bromo-2-naphthol, 1-iodo-2-naphthol, N-(2-iodophenyl)acetamide, 5-bromouracil, 2-iodo-N-methylbenzamide, and 2-iodobenzamide) was studied. For example, π-expanded coumarins, compounds with potential optical applications, were synthesized in very high yield, without the use of toxic reagents, in a one-pot reaction. In addition, we demonstrate that the irradiation source (halogen lamp) can be efficiently replaced by an LED without altering the reaction yield.

Reductions with sulfurated borohydrides. V. Reductions of ketones

1970 ◽  
Vol 48 (15) ◽  
pp. 2366-2371 ◽  
Author(s):  
J. M. Lalancette ◽  
A. Freche
Keyword(s):  
High Temperature ◽  
Carbonyl Group ◽  
Sodium Borohydride ◽  
Room Temperature ◽  
High Yield ◽  
High Yields ◽  
Very High

Ketones can be reduced with sulfurated sodium borohydride. Very high yield (≈90%) of the corresponding alcohol is obtained with the appropriate ratio of ketone and hydride at room temperature. The reaction is much influenced by the steric environment around the carbonyl group. At high temperature (65°) disulfides and tetrasulfides are produced. In some cases the structure of those sulfides have been established. Conjugated ketones can be reduced to the corresponding alcohols with very high yields.

81Br NQR and Crystal Structure of Ethylammonium Tribromomercurate(II), CH3CH2NH3HgBr3

1994 ◽  
Vol 49 (1-2) ◽  
pp. 202-208 ◽  
Author(s):  
Hiromitsu Terao ◽  
Tsutomu Okuda ◽  
Kichiro Koto ◽  
Shi-qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
High Temperatures ◽  
Title Compound ◽  
Room Temperature ◽  
Mercury Atom ◽  
Double Chain ◽  
Trigonal Bipyramidal ◽  
81Br Nqr ◽  
Increasing Temperature

Abstract The 81Br NQR triplet spectrum of (CH3CH2NH)3⊕(HgBr3)⊖ was measured in the range 77 K to near the m.p. (99~106°C) v1 decreases strongly with increasing temperature, exhibiting 136.784 MHz at 77 K and 128.129 MHz at 298 K. v2 decreases from 82.060 MHz at 77 K to 76.322 MHz at 298 K. v3 increases with temperature, showing v3 = 81.292 MHz at 77 K and 84.903 MHz at 298 K. Replacement of the ammonium hydrogens by deuterium produces a negative shift of v1 and positive ones of v2 and v3 at high temperatures. These shifts change with temperature from |~ 0| up to |~ 200| kHz. The crystal structure of the title compound was determined at room temperature: P 21/m, Z = 2, a = 1021.6(8) pm, b = 643.0(6) pm, c = 691.8(6) pm, β = 96.96 (4)°. The coordination of the mercury atom by the bromines is trigonal bipyramidal; by formation of bridges Hg··· Br··· Hg by one of the three bromines (Br(2)) of the planar HgBr⊖ ions a double chain of trigonal bipyramids is formed, running along the b-axis of the crystal. Br(1) and Br(3) are single bonded to Hg. The hydrogen bonds N -H···Br(1) and N -H ··· Br(3) (twice), connect the Hg-Br chains to planes lying parallel to the be plane at x = 0. The relations between the Br-NQR spectrum and the structure are discussed.

An easy approach to dihydrochalcones via chalcone in situ hydrogenation

2016 ◽  
Vol 88 (4) ◽  
pp. 349-361 ◽  
Author(s):  
Ana R. Jesus ◽  
Ana P. Marques ◽  
Amélia P. Rauter
Keyword(s):  
Room Temperature ◽  
Aromatic Aldehydes ◽  
Iron Chloride ◽  
High Yield ◽  
Microwave Assisted ◽  
Olefinic Double Bond ◽  
Single Reaction Product ◽  
Very High ◽  
Single Reaction

AbstractDihydrochalcones are polyphenols that exhibit a diversity of bioactivities, namely anti-inflammatory, antimicrobial and antiviral. We have explored the synthetic access to such molecular entities, and describe now an easy and scalable approach based on reduction of the olefinic double bond of chalcone precursors via in situ hydrogenation with the system Et3SiH-Pd/C in very high yield. The intermediate chalcones were synthesized also by a simple and efficient microwave-assisted Claisen–Schmidt condensation of aromatic aldehydes with acetophenones, conveniently protected with ethoxymethyl ether, if required. Chalcones were obtained as single reaction product in high yield in 2–3 h, while under conventional conditions at room temperature the reaction was carried out with completion only after 24 h. In addition, microwave irradiation has proven very efficient for deprotection of ethoxymethyl ether with iron chloride in only 10 min and very high yield.

scholarly journals One-Pot Synthesis of (Z)-β-Halovinyl Ketones via the Cascade of Sonogashira Coupling and Hydrohalogenation

2021 ◽  
Vol 8 ◽  
Author(s):  
Fa-Jie Chen ◽  
Zhenguo Hua ◽  
Jianhui Chen ◽  
Jiajia Chen ◽  
Daesung Lee ◽  
...  
Keyword(s):  
Efficient Method ◽  
Room Temperature ◽  
Copper Catalyst ◽  
High Yield ◽  
Sonogashira Coupling ◽  
Terminal Alkynes ◽  
Acid Chlorides ◽  
Triflic Acid ◽  
One Pot

Herein, we report an efficient method for the synthesis of (Z)-β-halovinyl ketones through a one-pot Sonogashira coupling and hydrohalogenation reaction promoted by palladium-copper catalyst and Brønsted acid. The ynone intermediates are generated in situ from readily available acid chlorides and terminal alkynes at room temperature, which are directly converted to (Z)-β-halovinyl ketones by treating with triflic acid. This method avoids the use of an external halogen source and features broad substrate scope, high yield, and good to excellent stereoselectivity.

Tetraguanidium Hexabromocadmate, [C(NH2)3]4[CdBr6]. Crystal Structure and Bromine Nuclear Quadrupole Resonance

1994 ◽  
Vol 49 (1-2) ◽  
pp. 223-231 ◽  
Author(s):  
V.G. Krishnan ◽  
Shi-qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Room Temperature ◽  
Negative Temperature ◽  
Temperature Coefficients ◽  
Moment Ratio ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole Moment ◽  
Nuclear Quadrupole

AbstractThe 79, 81Br NQR spectra of tetraguanidinium hexabromocadmate, [C(NH2)3]4[CdBr6] have been studied as a function of temperature from 77 K to 390 K and the crystal structure of the compound was determined at room temperature. The title compound crystallizes monoclinic, P21/c, with four formula units in the unit cell, a = 839.2(3) pm, b = 1895.8(6) pm, c= 1527.4(5) pm, β= 108.14(1)°. The anion [CdBr6]4⊖ is an isolated octahedron, with bond lengths 275≤d(Cd-Br)/pm ≤ 281, and bond angles 88 ≤(Br-Cd-Br)/° ≤95, slightly distorted by hydrogen bonds N -H ··· Br. The 81Br NQR sextet, in dependence from temperature, shows positive and negative temperature coefficients. At 77 K the 81Br NQR frequencies have been found between 42.42 MHz and 31.99 MHz; the 79Br NQR at the frequencies expected from the nuclear quadrupole moment ratio Q(79Br)/Q(81Br). Relations between the 81Br NQR spectrum, the crystal structure, and the hydrogen bonds are discussed.

scholarly journals Crystal structure of (S)-2-[(3S,8S,9S,10R,13S,14S,17R)-3-hydroxy-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl]-N-methoxy-N-methylpropanamide (Fernholz Weinreb amide)

2015 ◽  
Vol 71 (3) ◽  
pp. 275-277 ◽  
Author(s):  
Elvar Ørn Viktorsson ◽  
Ove Alexander Høgmoen Åstrand ◽  
Rasha Sabah Haseeb ◽  
Carl Henrik Görbitz ◽  
Pål Rongved
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
High Yield ◽  
Carbonyl Groups ◽  
Asymmetric Unit ◽  
Synthetic Pathway ◽  
Compound C ◽  
Weinreb Amide ◽  
Important Intermediate

The literature compound 3β-hydroxy-bisnor-5-cholenic aldehyde is an important intermediate for the synthesis of new modulators of the nuclear oxysterol receptor LiverX. As part of our ongoing search for new LXR antagonists, the title compound, C24H39NO3, has proven to be an important intermediate in our new synthetic pathway, giving the corresponding aldehyde in high yield and in only three steps from the commercially available 3β-hydroxy-bisnor-5-cholenic acid. The title amide crystallized with two molecules in the asymmetric unit, linked into helices by O—H...O hydrogen bonds involving the hydroxy and carbonyl groups.

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