Search results for "heterocycle"
showing 10 items of 134 documents
rac-12-Selena-13,14-diazatricyclo[9.3.0.02,4]tetradeca-11,13-diene
2020
The centrosymmetric crystal structure of the title compound, C11H16N2Se, is built up from alternating strands of (R,R)- and (S,S)-enantiomers. These strands, which propagate along the c-axis direction, are composed of homochiral molecules related to each other by twofold screw axes. The shape of the molecule is an almost planar unit around the selenadiazole ring with a hexamethylene chain as an arched handle.
N,1-Bis(4-ethoxyphenyl)-2,6-dimethyl-4-oxo-1,4-dihydropyridine-3-carboxamide
2018
Condensation of ethyl acetoacetate and phenetidine gives the title compound, C24H26N2O4. The planar ethoxyphenyl group attached to the pyridine ring is twisted about 77.96 (11)° out of the plane of the N-ethoxycarboxamidopyridine unit. The carboxamide unit forms a dihedral angle of about 28.1 (2)° with the pyridine ring.
Single crystal X-ray structural dataset of 1,2,4-dithiazolium tetrafluoroborate
2022
Herein, we present the crystallographic dataset of 1,2,4-dithiazolium tetrafluoroborate. Single crystal X-ray structural analysis evidences that the 1,2,4-dithiazolium ring is almost planar. The 1,2,4-dithiazolium and tetrafluoroborate ions contribute in hydrogen bonding wherein the N-H·N hydrogen bonding in 1,2,4-dithiazolium dimer forms an eight-membered pseudo ring with the R22(8) Etter's graph set. The information provided in this data contributes to the understanding of structural chemistry and hydrogen bonding interactions in dithiazole derivatives.
Oligophenyls with Multiple Disulfide Bridges as Higher Homologues of Dibenzo[c,e][1,2]dithiin: Synthesis and Application in Lithium-Ion Batteries.
2020
Abstract Higher homologues of dibenzo[c,e][1,2]dithiin were synthesized from oligophenyls bearing multiple methylthio groups. Single‐crystal X‐ray analyses revealed their nonplanar structures and helical enantiomers of higher meta‐congener 6. Such dibenzo[1,2]dithiin homologues are demonstrated to be applicable to lithium‐ion batteries as cathode, displaying a high capacity of 118 mAh g−1 at a current density of 50 mA g−1.
Chalcogen‐Bonding Interactions in Telluroether Heterocycles [Te(CH2)m]n (n=1-4; m=3-7)
2020
The Te…Te secondary bonding interactions (SBI) in solid heterocyclic telluroethers were explored by preparing and structurally characterizing a series of [Te(CH2)m]n (n = 1‐4; m = 3‐7) species. The SBIs in 1,7‐Te2(CH2)10, 1,8‐Te2(CH2)12, 1,5,9‐Te3(CH2)9, 1,8,15‐Te3(CH2)18, 1,7,13,19‐Te4(CH2)20, 1,8,15,22‐Te4(CH2)24, and 1,9,17,25‐Te4(CH2)28 led to the tubular packing of the molecules, as has been observed previously for related thio‐ and selenoether rings. The nature of the intermolecular interactions was explored by solid‐state PBE0‐D3/pob‐TZVP calculations involving periodic boundary conditions. The packing of molecules in 1,7,13,19‐Te4(CH2)20, 1,8,15,22‐Te4(CH2)24, and 1,9,17,25‐Te4(CH2)…
One-pot synthesis of fluorinated 2-amino-pyrimidine-N-oxides. Competing pathways in the four-atom side-chain rearrangements of 1,2,4-oxadiazoles
2006
Abstract Trifluoromethylated 2-amino-pyrimidine N-oxides have been synthesized by reaction of the 3-amino-5-methyl-1,2,4-oxadiazole with trifluoromethyl-β-diketones in the presence of perchloric acid, followed by hydrolysis. In this ring-to-ring transformation an initial formation of (unisolated) 1,2,4-oxadiazole-pyrimidinium salts, and subsequent ring-opening at the oxadiazole moiety occurs. Isolation of 2-(hydroxyamino)-pyrimidine from the reaction mixture evidenced the presence of a competing pathway where the N(4) nitrogen of the oxadiazole is involved in the formation of a regioisomeric pyrimidinium salt. The effect of the trifluoromethyl group on the product distribution is discussed.…
The “nitrogen effect” : Complexation with macrocycles potentiates fused heterocycles to form halogen bonds in competitive solvents
2023
Weak intermolecular forces are typically very difficult to observe in highly competitive polar protic solvents as they are overwhelmed by the quantity of competing solvent. This is even more challenging for three-component ternary assemblies of pure organic compounds. In this work, we overcome these complications by leveraging the binding of fused aromatic N-heterocycles in an open resorcinarene cavity to template the formation of a three-component halogen-bonded ternary assembly in a protic polar solvent system. peerReviewed
Editorial: Emerging heterocycles as bioactive compounds
2023
Heterocycles represent a privileged scaffold due to their ability to interact with biological systems via heteroatoms. It is no coincidence that every year the Food and Drug Administration approves numerous new drugs that contain at least one heterocyclic system as active pharmacophoric part in their structure. Many heterocyclic compounds with therapeutic properties, including anticancer, antimicrobial, anti-inflammatory and so on, come from natural sources such as plants and animals, and medicinal chemists very often use them to study their chemical space and improve their biological activity. In fact, several efficient approaches for the formation of aromatic heterocyclic compounds and th…
Asymmetric Synthesis of Fluorinated Isoindolinones through Palladium-Catalyzed Carbonylative Amination of Enantioenriched Benzylic Carbamates
2015
The asymmetric synthesis of fluorinated isoindolinones has been achieved by a palladium-catalyzed aminocarbonylation reaction of the corresponding -fluoroalkyl o-iodobenzylamines. A base-mediated anti -hydride elimination process was suggested to explain the partial erosion of the optical purity observed in some cases. This mechanistic rationale enabled the minimization of this partial racemization by fine-tuning the pK(a) of the base.