Browse
Submit Data
Databases
API
Help

Dataset Information

7 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Phenylene-bridged bis(benzimidazolium) (BBIm²⁺): a dicationic organic photoredox catalyst.

ABSTRACT: A dicationic photoredox catalyst composed of phenylene-bridged bis(benzimidazolium) (BBIm²⁺) was designed, synthesised and demonstrated to promote the photochemical decarboxylative hydroxylation and dimerisation of carboxylic acids. The catalytic activity of BBIm²⁺ was higher than that for a monocation analogue, suggesting that the dicationic nature of BBIm²⁺ plays a key role in these decarboxylative reactions. The rate constant for the decay of the triplet-triplet absorption of the excited BBIm²⁺ increased with increasing concentration of the carboxylate anion with a saturated dependence, suggesting that photoinduced electron transfer occurs within the ion pair complex composed of the triplet excited state of BBIm²⁺ and a carboxylate anion.

SUBMITTER: Kodama T

PROVIDER: S-EPMC8162872 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Bis-Cyclometalated Indazole Chiral-at-Rhodium Catalyst for Asymmetric Photoredox Cyanoalkylations.

Project description:A new class of bis-cyclometalated rhodium(III) catalysts containing two inert cyclometalated 6-tert-butyl-2-phenyl-2H-indazole ligands and two labile acetonitriles is introduced. Single enantiomers (>99?%?ee) were obtained through a chiral-auxiliary-mediated approach using a monofluorinated salicyloxazoline. The new chiral-at-metal complex is capable of catalyzing the visible-light-induced enantioselective ?-cyanoalkylation of 2-acyl imidazoles in which it serves a dual function as the chiral Lewis acid catalyst for the asymmetric radical chemistry and at the same time as the photoredox catalyst for the visible-light-induced redox chemistry (up to 80?% yield, 4:1?d.r., and 95?%?ee, 12?examples).

| S-EPMC6916287 | biostudies-literature

Phenylene-Bridged Perylene Monoimides as Acceptors for Organic Solar Cells: A Study on the Structure-Property Relationship.

Project description:A series of non-fullerene acceptors based on perylene monoimides coupled in the peri position through phenylene linkers were synthesized via Suzuki-coupling reactions. Various substitution patterns were investigated using density functional theory (DFT) calculations in combination with experimental data to elucidate the geometry and their optical and electrochemical properties. Further investigations of the bulk properties with grazing incidence wide angle X-ray scattering (GIWAXS) gave insight into the stacking behavior of the acceptor thin films. Electrochemical and morphological properties correlate with the photovoltaic performance of devices with the polymeric donor PBDB-T and a maximum efficiency of 3.17 % was reached. The study gives detailed information about structure-property relationships of perylene-linker-perylene compounds.

| S-EPMC9313791 | biostudies-literature

Alkyl Radical Addition to Aliphatic and Aromatic N-Acylhydrazones Using an Organic Photoredox Catalyst.

Project description:Increased versatility of intermolecular radical addition to imino acceptors via photoredox catalysis is reported. Primary and secondary radicals, generated via visible-light photocatalysis from alkyl biscatecholatosilicates with organocatalyst 4CzIPN, add successfully to both aromatic and aliphatic N-acylhydrazones in the presence of MgCl2. With N-benzoylhydrazones, a simple reductive cleavage of the N-N bond of the hydrazine adduct furnishes the free amine. Synthetic utility is exemplified in a synthetic application toward repaglinide, a clinically important hypoglycemic agent.

| S-EPMC6900872 | biostudies-literature

Bis(5,6-dicarboxy-benzimidazolium) sulfate monohydrate.

Project description:In the title compound, 2C(9)H(7)N(2)O(4) (+)·SO(4) (2-)·H(2)O, the sulfate S atom and the water O atom reside on a crystallographic twofold axis. In the crystal, the component species are linked by N-H?O, O-H?O and C-H?O hydrogen bonds, forming a three-dimensional network structure. An intramol-ecular O-H?O link is seen in the cation.

| S-EPMC2969668 | biostudies-literature

Bis(benzimidazolium) naphthalene-1,5-disulfonate trihydrate.

Project description:The title compound, 2C(7)H(7)N(2) (+)·C(10)H(6)O(6)S(2) (2-)·3H(2)O, consists of two crystallographically independent benzimidazolium cations, two independent naphthalene-1,5-disulfonate dianions (both generated by inversion) and three water mol-ecules. These components construct an infinite three-dimensional framework in the crystal structure via O-H⋯O and N-H⋯O hydrogen bonds.

| S-EPMC2960975 | biostudies-literature

Bis(diallyl-benzimidazolium) tetra-bromidocuprate(II).

Project description:The structure of the title ionic copper(II) compound, (C(13)H(15)N(2))(2)[CuBr(4)], is built up of isolated 1,3-diallyl-benzimidazolium cations and [CuBr(4)](2-) anions which are inter-connected by electrostatic inter-actions. Differences in packing of the heterocyclic cores results in a different structure compared with earlier investigated chloride and bromide analogues.

| S-EPMC2961985 | biostudies-literature

Bis(1,3-diethyl-benzimidazolium) tetra-bromidomercurate(II).

Project description:In the title compound, (C(11)H(15)N(2))(2)[HgBr(4)], the tetra-coordinated Hg(II) center of the complex anion adopts a distorted tetra-hedral geometry [Hg-Br = 2.5755 (8)-2.623 (11) Å and Br-Hg-Br = 103.78 (19)-116.4 (3)°]. One of the Br atoms is disordered over two sites [site-occupancy factors = 0.51 (6) and 0.49 (6)]. The N-C-N angles in the cations are 110.7 (6) and 111.4 (7)°. In the crystal packing, a supra-molecular chain is formed via both weak inter-molecular C-H⋯Br hydrogen bonds and π-π aromatic ring stacking inter-actions [centroid-centroid separation = 3.803 (1) Å].

| S-EPMC2971972 | biostudies-literature

Site-selective remote C(sp3)-H heteroarylation of amides via organic photoredox catalysis.

Project description:Radical translocation processes triggered by nitrogen-centered radicals (NCRs), such as 1,5-hydrogen atom transfers (1,5-HAT), demonstrated by the well-established Hofmann-Löffler-Freytag (HLF) reaction, provide an attractive approach for the controllable and selective functionalization of remote inert C(sp3)-H bonds. Here we report an amidyl radical-triggered site-selective remote C(sp3)-H heteroarylation of amides under organic photoredox conditions. This approach provides a mild and highly regioselective reaction affording remote C(sp3)-H heteroarylated amides at room temperature under transition-metal free, weakly basic, and redox-neutral conditions. Non-prefunctionalized heteroarenes, such as purines, thiazolopyridines, benzoxazole, benzothiazoles, benzothiophene, benzofuran, thiazoles and quinoxalines, can be alkylated directly. Sequential and orthogonal C-H functionalization of different heteroarenes by taking advantage pH value or polarity of radicals has also been achieved. DFT calculations explain and can predict the site-selectivity and reactivity of this reaction. This strategy expands the scope of the Minisci reaction and serves as its alternative and potential complement.

| S-EPMC6800443 | biostudies-literature

One-Step Synthesis of [18F]Aromatic Electrophile Prosthetic Groups via Organic Photoredox Catalysis.

Project description:To avoid the harsh conditions that are oftentimes adopted in direct radiofluorination reactions, conjugation of bioactive ligands with 18F-labeled prosthetic groups has become an important strategy to construct novel PET agents under mild conditions when the ligands are structurally sensitive. Prosthetic groups with [18F]fluoroarene motifs are especially appealing because of their stability in physiological environments. However, their preparation can be intricate, often requiring multistep radiosynthesis with functional group conversions to prevent the decomposition of unprotected reactive prosthetic groups during the harsh radiofluorination. Here, we report a general and simple method to generate a variety of highly reactive 18F-labeled electrophiles via one-step organophotoredox-mediated radiofluorination. The method benefits from high step-economy, reaction efficiency, functional group tolerance, and easily accessible precursors. The obtained prosthetic groups have been successfully applied in PET agent construction and subsequent imaging studies, thereby demonstrating the feasibility of this synthetic method in promoting imaging and biomedical research.

| S-EPMC11363353 | biostudies-literature

19F- and 18F-Arene Deoxyfluorination via Organic Photoredox-Catalysed Polarity-Reversed Nucleophilic Aromatic Substitution.

Project description:Nucleophilic aromatic substitution (SNAr) is routinely used to install 19F- and 18F- in aromatic molecules, but is typically limited to electron-deficient arenes due to kinetic barriers associated with C-F bond formation. Here we demonstrate that a polarity-reversed photoredox-catalysed arene deoxyfluorination operating via cation radical-accelerated nucleophilic aromatic substitution (CRA-SNAr) enables the fluorination of electron-rich arenes with 19F- and 18F- under mild conditions, thus complementing the traditional arene polarity requirements necessary for SNAr-based fluorination. The utility of our radiofluorination strategy is highlighted by short reaction times, compatibility with multiple nucleofuges, and high radiofluorination yields, especially that of an important cancer positron emission tomography (PET) agent [18F]5-fluorouracil ([18F]FU). Taken together, our fluorination approach enables the development of fluorinated and radiofluorinated compounds that can be difficult to access by classical SNAr strategies, with the potential for use in the synthesis and discovery of PET radiopharmaceuticals.

| S-EPMC8009013 | biostudies-literature