Search results for "thiourea"

Organocatalytic Enantioselective Synthesis of Pyrazoles Bearing a Quaternary Stereocenter

2016

An efficient one-pot asymmetric synthesis of pyrazoles bearing a chiral quaternary stereocenter has been developed. Quinine-derived thiourea catalyzed the enantioselective addition of pyrazolones to isatin-derived ketimines, providing the corresponding acetylated pyrazoles after in situ treatment with Ac2O/Et3N. The corresponding pyrazoles were afforded in high yields and excellent enantioselectivities.

Effects of K(ATP) channel modulators on acetylcholine release from guinea-pig isolated atria and small intestine.

2002

The effects of K(ATP) channel blockers (glibenclamide, HMR 1883, HMR 1372) and openers (cromakalim, pinacidil, diazoxide) on the electrically-evoked (5 Hz) release of [(3)H]acetylcholine were studied in isolated guinea-pig atria and myenteric plexus-longitudinal muscle preparations which had been preincubated with [(3)H]choline. Atria: Cromakalim (0.3 microM and 1 microM), pinacidil (10 microM) and diazoxide (30 microM) significantly reduced the stimulation-evoked release of [(3)H]acetylcholine. The inhibition produced by cromakalim and pinacidil was prevented by 1 microM of either HMR 1883, HMR 1372 or glibenclamide. The blockers alone significantly increased the release at concentrations …

Responses to histamine and selective H2-receptor agonists in lung parenchymal strips from normal and sensitized guinea-pigs.

1989

Histamine produces concentration-dependent contractions of lung parenchyma strips obtained from normal and sensitized guinea-pigs. The responsiveness of the sensitized lung strips to histamine was significantly increased compared to normal tissues. Clemizole (0.1 microM) was equally effective as an H1-antagonist in normal (dose-ratio 9.12) and sensitized (dose-ratio 9.77) tissues. The concentration-response curves to histamine were displaced to the left by cimetidine (0.1 microM to 0.1 mM) with similar dose-ratios in normal and sensitized tissues. Cimetidine enhanced maximal responses to histamine only in normal lung strips. The effects of submaximal equieffective concentrations of histamin…

Structural and Optical Study of Ga3+ Substitution in CuInS2 Nanoparticles Synthesized by a One-Pot Facile Method

2014

A one-pot method was used to synthesize CuInxGa1–xS2 nanoparticles by substituting In3+ with Ga3+. The samples with composition of gallium ranging from 0% to 100% were synthesized by solving copper chloride, indium trichloride, gallium acetylacetonate, and thiourea as precursors in 1-octadecene, oleylamine, and oleic acid as noncoordinating, coordinating, and capping agent solvents, respectively. Depending on the chemical composition and synthesis conditions, the morphology of the as-synthesized nanoparticles obtained was trigonal, semitrigonal, hexagonal, and quasi-spherical. X-ray photoelectron spectroscopy and X-ray diffraction confirmed that Ga3+ substituted In3+ without any segregation…

Structural and optical properties of Fe and Zn substituted CuInS2 nanoparticles synthesized by a one-pot facile method

2015

We substitute indium present in the CuInS2 ternary compound by iron and zinc using a facile one-pot synthesis method. The quaternary compound of CuIn1−xMxS2 (M = Fe and Zn) was synthesized by dissolving CuCl, InCl3, FeCl3, Zn(ac)2 and SC(NH2)2 as precursors in 1-octadecene, oleylamine and oleic acid as non-coordinating, coordinating and capping agent solvents, respectively. Oleic acid, oleylamine and thiourea were used respectively as a hard Lewis base, borderline Lewis base (in comparison with oleic acid) and soft Lewis base to form appropriate complexes. The complex formation, structure, and optical properties of CuIn1−xMxS2 (M = Fe and Zn) nanoparticles were studied by Fourier transform …

Enhanced bistability by guest inclusion in Fe(ii) spin crossover porous coordination polymers

2012

Inclusion of thiourea guest molecules in the tridimensional spin crossover porous coordination polymers {[Fe(pyrazine)[M(CN)(4)]} (M = Pd, Pt) leads to novel clathrates exhibiting unprecedented large thermal hysteresis loops of ca. 60 K wide centered near room temperature.

Enantioselective Mannich reaction of β-keto esters with aromatic and aliphatic imines using a cooperatively assisted bifunctional catalyst

2014

An efficient urea-enhanced thiourea catalyst enables the enantioselective Mannich reaction between β-keto esters and N-Boc-protected imines under mild conditions and minimal catalyst loading (1–3 mol %). Aliphatic and aromatic substituents are tolerated on both reaction partners, affording the products in good enantiomeric purity. The corresponding β-amino ketones can readily be accessed via decarboxylation without loss of enantiomeric purity.

Stereoselective Synthesis and Cytoselective Toxicity of Monoterpene-Fused 2-Imino-1,3-thiazines

2014

Starting from pinane-, apopinane- and carane-based 1,3-amino alcohols obtained from monoterpene-based β-amino acids, a library of monoterpene-fused 2-imino-1,3-thiazines as main products and 2-thioxo-1,3-oxazines as side-products were prepared via two- or three-step syntheses. When thiourea adducts prepared from 1,3-amino alcohols and aryl isothiocyanates were reacted with CDI under mild conditions, O-imidazolylcarbonyl intermediates were isolated which could be transformed to the desired 1,3-thiazines under microwave conditions. 1,3-Thiazines and 2-thioxo-1,3-oxazine side-products could also be prepared in one-step reactions through the application of CDI and microwave irradiation. The rin…

Synthesis of Pyrrolo-Condensed Derivatives with Potential Antiviral Activity

2014

CCDC 1469018: Experimental Crystal Structure Determination

2016

Related Article: Filip Topić and Kari Rissanen|2016|J.Am.Chem.Soc.|138|6610|doi:10.1021/jacs.6b02854