a simple, efficient, and high yielding one-pot protocol has been developed for the synthesis of 4h-benzo[b]pyrans scaffolds installing a three-component tandem knoevenagel-cyclocondensation reaction of an aldehyde, malononitrile and dimedone using guanidinium chloride as polyfunctional organocatalyst under solvent-free conditions in high to excellent yields. various aromatic aldehydes were util...

The aim of the work was to study antioxidant activity 4-R-3- (morpholinomethyl)-4H-1,2,4-triazole-5-thioles and their alkyl derivatives in vitro using method non-enzymatic initiation lipid peroxidation. Among 45 compounds studied, 8 showed varying degrees AOA. most pronounced AOA has 4-amino-3-(morpholinomethyl)-4H-1,2,4-triazole-5-thiol. It found that cases introduction alkyl-derivatives 4-R-3...

The new 2,9-dimethyl-4H-oxazolo[5’,4’:4,5]pyrano[3,2-f]quinolin-4-one was successfully prepared through the three-component iodine-catalyzed reaction of n-butyl vinyl ether with 8-amino-2-methyl-4H-chromeno[3,4-d]oxazol-4-one. latter by reduction 2-methyl-8-nitro-4H-chromeno[3,4-d]oxazol-4-one Pd/C in a hydrogen atmosphere. above nitro compound synthesized condensation N-(4-hydroxy-6-nitro-2-ox...

Abstract Divacancy spins implement qubits with outstanding characteristics and capabilities in an industrial semiconductor host. On the other hand, there are still numerous open questions about physics of these important defects, for instance, spin relaxation has not been thoroughly studied yet. Here, we carry out a theoretical study on environmental spin-induced processes divacancy 4H polytype...

in this study, the synthesis of 4 h -chromenes of biological activity via a multicomponent reaction of dimedone, aromatic aldehydes and malononitrile catalyzed by glutamic acid as a catalyst was investigated. the structural features of the synthesized compounds were characterized by melting point, ir and 1 h nmr analysis. the catalyst being reported here is cheap, safe to handle and the whole p...

6-methyl- 1,2,4-triazine-3-(2h)-selenone-5(4h)-one(l) reacts in the presence of base with phenacyl bromide to give a mixture of compounds (2) and (3). this mixture is dehydrated in the presence of h,so, to give 3-phenyl-6 methyl-7h-selenazolo[3,2-b] [i ,2,4] triazin-7-one (6). for careful structure assignment of (6) its regioisomer 3-methyl-6-phenyl-4h-selenazolo [2,3-c] [ 1,2,4] triazin-4-one ...

Silicon carbide (4H) based metal–oxide–semiconductor field-effect transistors provide capabilities in high power and temperature inaccessible to silicon. However, the performance of thermally grown oxide-based devices remains limited by oxide/semiconductor interface defects. This research employs deposited dielectrics, Al2O3, rather than thermal oxidation. Investigation various pre-deposition p...

A facile, convenient, green and environmentally benign one-pot three-component synthesis of poly-functionalized 4H-pyrans and 4H-chromenes is described. A basic ionic liquid 2-(2-hydroxyethoxy)ethaneammonium formate was found to be an efficient catalyst or catalytically active solvent for the synthesis of those important classes of heterocyclic compounds.

Both 3C and 6H stacking faults have been observed in a low doped 4H-SiC epitaxial layer grown in a hot-wall CVD reactor on a heavily doped (off-axis) 4H-SiC substrate. They appear differently on the different parts of sample, with energetic dispersion ranging from 3.01 eV to 2.52 eV. Since they behave as natural type-II quantum wells in the 4H-SiC matrix, the thickness dependence of the exciton...