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This document summarizes a study on the use of chiral iron porphyrin complexes as catalysts for remote enantioselective epoxidation reactions. The study found that catalysts with an elongated linker were most effective for olefins that were four carbon atoms away from the lactam binding site. The presence of a hydrogen-bonding interaction between the catalyst and the substrate was also important for achieving high enantioselectivity. However, a high enantioselectivity could only be achieved if the substrate binding offered a kinetic advantage compared to a racemic catalyst. The study provides valuable insights into the factors that influence the enantioselectivity of epoxidation reactions. [Extracted from the article]

Treatment of N‐methyl‐S,S‐diaryl sulfoximines with methyl trifluoromethanesulfonate provides bench‐stable sulfoxinium salts in excellent yields. Applying them in Sonogashira‐, Heck‐ and Suzuki‐type cross‐coupling reactions leads to the corresponding products by sequential C−S bond cleavage and C−C bond formation. Electronic factors induced by substituents on the S‐aryl groups govern the coupling efficiency. [ABSTRACT FROM AUTHOR]

In recent years, the studies of RNA and its use for the development of RNA based vaccines have increased drastically. Although cyanine dyes are commonly used probes for studying nucleic acids, in a wide range of applications, there is still a growing need for better and brighter dyes. To meet this demand, we have systematically studied the structure of SYBR green-related cyanine dyes to gain a deeper understanding of their interactions with biomolecules especially how they interact with nucleic acids and the structural components which makes them strongly fluorescent. Herein, five new dyes were synthesized, and their photophysical properties were evaluated. Observations of photophysical characteristics were compared to calculations by using density functional theory in its ground state and time-dependent form to model the optical absorption spectra and excited state properties of the selected molecules. Single crystal X-ray crystal structures of five cyanine dyes were determined and the interactions of the cyanine dye-DNA complex were studied by using molecular docking and molecular dynamics calculations. Three molecular structural features were discovered: a) removing the benzene ring from the thiazolium moiety of the dye lowers the fluorescence drastically, and that the quantum yield can be enhanced, therefore increasing the fluorescence, by b) incorporating methanethiol substituent at the quinoline moiety instead of dimethylamine or c) changing the thiazolium moiety to an oxazolium moiety. [Display omitted] • Five new cyanine dyes were synthesized. • The main characteristics that affect the fluorescence of the dyes were recognized. • Up to 1050 times fluorescence enhancement was observed. • X-ray crystal structures of five cyanine dyes were solved. • MD calculations suggested that studied dyes bind with the AT-rich minor groove of dsDNA. [ABSTRACT FROM AUTHOR]

Biofilms represent a key challenge in the treatment of microbial infections; for instance, Staphylococcus aureus causes chronic or fatal infections by forming biofilms on medical devices. Herein, the fungus Arcopilus navicularis was found to produce a novel family of PKS-NRPS metabolites that are able to disrupt preformed biofilms of S. aureus . Arcopilins A-F ( 1 - 6 ), tetramic acids, and arcopilin G ( 7 ), a 2-pyridone, were elucidated using HR-ESI-MS and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy. Their absolute configuration was established by the synthesis of MPTA-esters for 2 , analysis of 1 H- 1 H coupling constants, and ROESY correlations, along with comparison with the crystal structure of 7 . Arcopilin A ( 1 ) not only effectively disrupts preformed biofilms of S. aureus but also potentiates the activity of gentamicin and vancomycin up to 115- and 31-fold times, respectively. Our findings demonstrate the potential application of arcopilins for the conjugated treatment of infections caused by S. aureus with antibiotics unable to disrupt preformed biofilms.

Maneb is a manganese(II)-containing fungicide with a multi-site effect and no resistance, therefore it is widely applied in many parts of the world. There is, however, mounting evidence for neurotoxic effects with Parkinson-like symptoms (manganism) related to usage of Maneb. Due to its insolubility in most solvents and its paramagnetism, structural elucidation is not trivial, and thus its exact molecular structure remains unknown. We report herein a synthesis procedure to prepare Maneb reproducibly in pure form and the use of various analytical techniques including X-ray diffraction, X-ray absorption spectroscopy and electron diffraction to determine the molecular structure of Maneb in the solid state and also in solution., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Copper(I)-catalyzed domino reactions of 2-azido sulfoximines with 1-iodoalkynes yield fused triazolyl-containing benzothiadiazine-1-oxides. The protocol features the synthesis of two fused heterocyclic rings in one step with good to excellent yields and a broad functional group tolerance. Detailed mechanistic investigations indicate that a copper π-complex initiates a cycloaddition and oxidative C-N coupling reaction sequence. The results suggest an interrupted domino process involving an iodinated triazole as a key intermediate., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

The synthesis of iodine(I) complexes with either benzoimidazole or carbazole-derived sp 2 N-containing Lewis bases is described, as well as their corresponding silver(I) complexes. The addition of elemental iodine to the linear two-coordinate Ag(I) complexes produces iodine(I) complexes with a three-center four-electron (3c-4e) [N-I-N] + bond. The 1 H and 1 H- 15 N HMBC NMR studies unambiguously confirm the formation of the complexes in all cases via the [N-Ag-N] + →[N-I-N] + cation exchange, with the 15 N NMR chemical shift change between 94 to 111 ppm when compared to the free ligand. The single crystal X-ray crystallographic studies on eight I + complexes revealed highly symmetrical [N-I-N] + bonds with I-N bond distances of 2.21-2.26 Å and N-I-N angles of 177-180°, whilst some of the corresponding Ag + complexes showed a clear deviation from linearity with N-Ag-N angles of ca. 150° and Ag-N bond distances of 2.09-2.18 Å., (© 2021 Wiley-VCH GmbH.)

Neutral halogen-bonded O-I-N complexes were prepared from in situ formed carbonyl hypoiodites and aromatic organic bases. The carbonyl hypoiodites have a strongly polarized iodine atom with larger σ-holes than any known uncharged halogen bond donor. Modulating the Lewis basicity of the selected pyridine derivatives and carboxylates leads to halogen-bonded complexes where the classical O-I⋅⋅⋅N halogen bond transforms more into a halogen-bonded COO - ⋅⋅⋅I-N + ion-pair (salt) with an asymmetric O-I-N moiety. X-ray analyses, NMR studies, and calculations reveal the halogen bonding geometries of the carbonyl hypoiodite-based O-I-N complexes, confirming that in the solid-state the iodine atom is much closer to the N-atom of the pyridine derivatives than its original position at the carboxylate O-atom., (© 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Two isostructural trans -[MI 2 (CNXyl) 2 ]·I 2 (M = Pd or Pt; CNXyl = 2,6-dimethylphenyl isocyanide) metallopolymeric cocrystals containing uncommon bifurcated iodine···(metal-iodide) contact were obtained. In addition to classical halogen bonding, single-crystal X-ray diffraction analysis revealed a rare type of metal-involved stabilizing contact in both cocrystals. The nature of the noncovalent contact was studied computationally (via DFT, electrostatic surface potential, electron localization function, quantum theory of atoms in molecules, and noncovalent interactions plot methods). Studies confirmed that the I···I halogen bond is the strongest noncovalent interaction in the systems, followed by weaker I···M interaction. The electrophilic and nucleophilic nature of atoms participating in I···M interaction was studied with ED/ESP minima analysis. In trans -[PtI 2 (CNXyl) 2 ]·I 2 cocrystal, Pt atoms act as weak nucleophiles in I···Pt interaction. In the case of trans -[PdI 2 (CNXyl) 2 ]·I 2 cocrystal, electrophilic/nucleophilic roles of Pd and I are not clear, and thus the quasimetallophilic nature of the I···Pd interaction was suggested.