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Disubstituted isothiazolo[4,3-b]pyridines are known inhibitors of cyclin G-associated kinase. Since 3-substituted-7-aryl-isothiazolo[4,3-b]pyridines remain elusive, a strategy was established to prepare this chemotype, starting from 2,4-dichloro-3-nitropyridine. Selective C-4 arylation using ligand-free Suzuki-Miyaura coupling and palladium-catalyzed aminocarbonylation functioned as key steps in the synthesis. The 3-N-morpholinyl-7-(3,4-dimethoxyphenyl)-isothiazolo[4,3-b]pyridine was completely devoid of GAK affinity, in contrast to its 3,5- and 3,6-disubstituted congeners. Molecular modeling was applied to rationalize its inactivity as a GAK ligand. [ABSTRACT FROM AUTHOR]

The title compound, C27H20N4O3S, crystallizes in the monoclinic system, space group P21/n, with Z = 4. The global shape of the molecule is determined by the orientation of the substituents on the central 4H-1,2,4-triazole ring. The nitrophenyl ring, phenyl ring, and naphthalene ring system are oriented at dihedral angles of 82.95 (17), 77.14 (18) and 89.46 (15)°, respectively, with respect to the triazole ring. The crystal packing features chain formation in the b-axis direction by S...O interactions. A Hirshfeld surface analysis indicates that the highest contributions to surface contacts arise from contacts in which H atoms are involved. [ABSTRACT FROM AUTHOR]

A new family of unsymmetrical boron chromophores chelated with two BF2 units, named BOPAM, has been developed via a one‐pot, three‐step reaction starting from commercially available thioamides via i) conversion to amidrazones, ii) condensation with pyrrole aldehydes, and iii) boron chelation. This synthetic pathway has been proven to be highly efficient, having a broad substrate tolerance and giving the BOPAM products high yield. Notably, some of the BOPAM dyes show interesting photophysical properties with fluorescence quantum yields up to 0.98 in toluene. A fine‐tuning of their emissive properties has been attained through tailored molecular design strategies guided by in‐depth computational investigations. Tailored substitution with electron‐donating groups at the BOPAM ring leads to the opening of a non‐radiative decay channel involving a dark state and consequently a significant quenching of the fluorescence. The study is complemented by exhaustive steady‐state and time‐resolved spectroscopic measurements. [ABSTRACT FROM AUTHOR]

Isothiazolo[4,3- b ]pyridines have been extensively explored as inhibitors of cyclin G-associated kinase (GAK). In order to expand the structure-activity relationship study and to discover other chemotypes that act as GAK inhibitors, the closely related isothiazolo[4,5- b ]pyridine scaffold was explored. An easy and efficient synthetic procedure to access 3,5- and 3,6-dihalogenated isothiazolo[4,5- b ]pyridines as key building blocks was developed. Regioselective functionalization with various substituents was performed. None of the newly synthesized isothiazolo[4,5- b ]pyridines were active as GAK inhibitors. Molecular modeling was applied to rationalise their inactivity as GAK binders.

Pyrrolo[2,3- b ]quinoxaline derivatives are known to possess antioxidant, anticancer, and antibacterial properties. Here we report the successful synthesis of five derivatives of 3-hydroxy-3-pyrroline-2-one through substitution. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was employed to evaluate the antioxidant activity of the compounds. Out of these, ethyl 1,2-diphenyl-1 H -pyrrolo[2,3- b ]quinoxaline-3-carboxylate (3a) demonstrated the greatest potential as a radical scavenger. Thermodynamic and kinetic calculations of the radical scavenging activity indicated that 3a exhibited HO˙ radical scavenging activity with the overall rate constant of 8.56 × 10 8 M -1 s -1 in pentyl ethanoate; however, it was incapable of scavenging hydroperoxyl radicals in nonpolar media. In non-polar environments, the hydroxyl radical scavenging capability of 3a is fairly similar to that of reference antioxidants such as Trolox, melatonin, indole-3-carbinol, and gallic acid. Hence, in the physiological lipid environment, 3a holds promise as a scavenger of HO˙ radicals., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A new quinoline derivative, namely, 6-(di-ethyl-amino)-4-phenyl-2-(pyridin-2-yl)quinoline, C 24 H 23 N 3 ( QP ), and its Mn II complex aqua-1κ O -di-μ-chlorido-1:2κ 4 Cl : Cl -di-chlorido-1κ Cl ,2κ Cl -bis-[6-(di-ethyl-amino)-4-phenyl-2-(pyridin-2-yl)quinoline]-1κ 2 N 1 , N 2 ;2κ 2 N 1 , N 2 -dimanganese(II), [Mn 2 Cl 4 (C 24 H 23 N 3 ) 2 (H 2 O)] ( MnQP ), were synthesized. Their compositions have been determined with ESI-MS, IR, and 1 H NMR spectroscopy. The crystal-structure determination of MnQP revealed a dinuclear complex with a central four-membered Mn 2 Cl 2 ring. Both Mn II atoms bind to an additional Cl atom and to two N atoms of the QP ligand. One Mn II atom expands its coordination sphere with an extra water mol-ecule, resulting in a distorted octa-hedral shape. The second Mn II atom shows a distorted trigonal-bipyramidal shape. The UV-vis absorption and emission spectra of the examined compounds were studied. Furthermore, when investigating the aggregation-induced emission (AIE) properties, it was found that the fluorescent color changes from blue to green and eventually becomes yellow as the fraction of water in the THF/water mixture increases from 0% to 99%. In particular, these color and intensity changes are most pronounced at a water fraction of 60%. The crystal structure contains disordered solvent mol-ecules, which could not be modeled. The SQUEEZE procedure [Spek (2015 ▸). Acta Cryst. C 71 , 9-18] was used to obtain information on the type and qu-antity of solvent mol-ecules, which resulted in 44 electrons in a void volume of 274 Å 3 , corresponding to approximately 1.7 mol-ecules of ethanol in the unit cell. These ethanol mol-ecules are not considered in the given chemical formula and other crystal data., (© Le Thi Hong et al. 2024.)

Three organoplatinum(II) complexes bearing natural aryl-olefin and quinoline derivatives, namely, [4-meth-oxy-5-(2-meth-oxy-2-oxoeth-oxy)-2-(prop-2-en-1-yl)phen-yl](quinolin-8-olato)platinum(II), [Pt(C 13 H 15 O 4 )(C 9 H 6 NO)], ( I ), [4-meth-oxy-5-(2-oxo-2-propoxyeth-oxy)-2-(prop-2-en-1-yl)phen-yl](quinoline-2-carboxy-l-ato)platinum(II), [Pt(C 15 H 19 O 4 )(C 10 H 6 NO 2 )], ( II ), and chlorido-[4-meth-oxy-5-(2-oxo-2-propoxyeth-oxy)-2-(prop-2-en-1-yl)phen-yl](quinoline)-plat-inum(II), [Pt(C 15 H 19 O 4 )Cl(C 9 H 7 N)], ( III ), were synthesized and structurally characterized by IR and 1 H NMR spectroscopy, and by single-crystal X-ray diffraction. The results showed that the cyclo-platinated aryl-olefin coordinates with Pt II via the carbon atom of the phenyl ring and the C=C olefinic group. The deprotonated 8-hy-droxy-quinoline (C 9 H 6 NO) and quinoline-2-carb-oxy-lic acid (C 10 H 6 NO 2 ) coordinate with the Pt II atom via the N and O atoms in complexes ( I ) and ( II ) while the quinoline (C 9 H 7 N) coordinates via the N atom in ( III ). Moreover, the coordinating N atom in complexes ( I )-( III ) is in the cis position compared to the C=C olefinic group. The crystal packing is characterized by C-H⋯π, C-H⋯O [for ( II ) and ( III )], C-H⋯Cl [for ( III ) and π-π [for ( I )] inter-actions., (© Chi et al. 2024.)

The complex [Pt(C 9 H 6 NO)Cl(C 2 H 4 )], (I), was synthesized and structurally characterized by ESI mass spectrometry, IR, NMR spectroscopy, DFT calculations and X-ray diffraction. The results showed that the deprotonated 8-hy-droxy-quinoline (C 9 H 6 NO) coordinates with the Pt II atom via the N and O atoms while the ethyl-ene coordinates in the η 2 manner and in the trans position compared to the coordinating N atom. The crystal packing is characterized by C-H⋯O, C-H⋯π, Cl⋯π and Pt⋯π inter-actions. Complex (I) showed high selective activity against Lu-1 and Hep-G2 cell lines with IC 50 values of 0.8 and 0.4 µ M , respectively, 54 and 33-fold more active than cisplatin. In particular, complex (I) is about 10 times less toxic to normal cells (HEK-293) than cancer cells Lu-1 and Hep-G2. Furthermore, the reaction of complex (I) with guanine at the N7 position was proposed and investigated using the DFT method. The results indicated that replacement of the ethyl-ene ligand with guanine is thermodynamically more favorable than the Cl ligand and that the reaction occurs via two consecutive steps, namely the replacement of ethyl-ene with H 2 O and the water with the guanine mol-ecule., (© Chi et al. 2024.)

The title compound, C 27 H 20 N 4 O 3 S, crystallizes in the monoclinic system, space group P 2 1 / n , with Z = 4. The global shape of the mol-ecule is determined by the orientation of the substituents on the central 4 H -1,2,4-triazole ring. The nitro-phenyl ring, phenyl ring, and naphthalene ring system are oriented at dihedral angles of 82.95 (17), 77.14 (18) and 89.46 (15)°, respectively, with respect to the triazole ring. The crystal packing features chain formation in the b -axis direction by S⋯O inter-actions. A Hirshfeld surface analysis indicates that the highest contributions to surface contacts arise from contacts in which H atoms are involved., (© Le et al. 2024.)