Thermal and Photoinduced Radical Cascade Annulation using Aryl Isonitriles: An Approach to Quinoline-Derived Benzophosphole Oxides.

Herein, we present a radical cascade addition cyclization sequence to access quinoline-based benzophosphole oxides from ortho-alkynylated aromatic phosphine oxides using various aryl isonitriles as radical acceptors and inexpensive tert-butyl-hydroperoxide (TBHP) as a terminal oxidant in the presence of a catalytic amount of silver acetate. Alternatively, the same cascade can be realized through a sustainable photochemical approach utilizing 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) as an organic photocatalyst at room temperature. The introduced modular approach shows broad functional group tolerance and offers straightforward access to complex P,N-containing polyheterocyclic arenes.

Access to Polyheterocyclic Compounds through Iron(II)-Mediated Radical Cascade Cyclization Utilizing 2-Ethynylbenzaldehydes and Aryl Isonitriles.

An oxidative radical cascade addition cyclization approach for the synthesis of quinoline-based π-extended polyheterocyclic compounds is reported. Eco-friendly iron catalysis and inexpensive -butylhydroperoxide (TBHP) as the oxidant have been utilized in the transformation of various readily available ortho-alkynylated aromatic aldehydes as radical precursors with aryl isonitriles as radical acceptors. Indole and thiophene-based carbaldehydes allow the preparation of quinolines that are π-conjugated with an additional heteroarene moiety in a single sequence by applying the introduced method.

Organic Synthesis Using Nitroxides.

Nitroxides, also known as nitroxyl radicals, are long-lived or stable radicals with the general structure RRN-O. The spin distribution over the nitroxide N and O atoms contributes to the thermodynamic stability of these radicals. The presence of bulky N-substituents R and R prevents nitroxide radical dimerization, ensuring their kinetic stability.

Enantioselective Copper-Catalyzed Fukuyama Indole Synthesis from 2-Vinylphenyl Isocyanides.

Enantioenriched chiral indoles are of high interest for the pharmaceutical and agrochemical industries. Herein, we present an asymmetric Fukuyama indole synthesis through a mild and efficient radical cascade reaction to access 2-fluoroalkylated 3-(α-cyanobenzylated) indoles by stereochemical control with a chiral copper-bisoxazoline complex using 2-vinylphenyl arylisocyanides as radical acceptors and fluoroalkyl iodides as C-radical precursors. Radical addition to the isonitrile moiety, 5-trig cyclization, and Cu-catalyzed stereoselective cyanation provide the targeted indoles with excellent enantioselectivity and good yields.

2,3-Difunctionalized Indoles via Radical Acylation or Trifluoromethylation of -Alkynylphenyl Isonitriles.

A radical cascade to 2,3-disubstituted indoles proceeding via acylation or trifluoromethylation of -alkynylphenyl isonitriles is presented. In these cascades, two C-C bonds and one C-O bond are formed using an inexpensive oxidant and a catalytic copper or iron salt. The starting isonitriles are easily accessible, and commercially available aldehydes and fluoromethylation reagents serve as reaction partners.

Organic Electrochemical Transistors Based on the Conjugated Polyelectrolyte PCPDTBT-SO K (CPE-K).

PCPDTBT-SO K (CPE-K), a conjugated polyelectrolyte, is presented as a mixed conductor material that can be used to fabricate high transconductance accumulation mode organic electrochemical transistors (OECTs). OECTs are utilized in a wide range of applications such as analyte detection, neural interfacing, impedance sensing, and neuromorphic computing. The use of interdigitated contacts to enable high transconductance in a relatively small device area in comparison to standard contacts is demonstrated.

Photoswitchable Conjugated Oligoelectrolytes for a Light-Induced Change of Membrane Morphology.

The synthesis of a new conjugated oligoelectrolyte (COE), namely DSAzB, is described, which contains a conjugated core bearing a diazene moiety in the center of its electronically delocalized structure. Similar to structurally related phenylenevinylene-based COEs, DSAzB readily intercalates into model and natural lipid bilayer membranes. Photoinduced isomerization transforms the linear trans COE into a bent or C-shape form.

Living Bioelectrochemical Composites.

Composites, in which two or more material elements are combined to provide properties unattainable by single components, have a historical record dating to ancient times. Few include a living microbial community as a key design element. A logical basis for enabling bioelectronic composites stems from the phenomenon that certain microorganisms transfer electrons to external surfaces, such as an electrode.

Towards understanding the doping mechanism of organic semiconductors by Lewis acids.

Precise doping of organic semiconductors allows control over the conductivity of these materials, an essential parameter in electronic applications. Although Lewis acids have recently shown promise as dopants for solution-processed polymers, their doping mechanism is not yet fully understood. In this study, we found that B(CF) is a superior dopant to the other Lewis acids investigated (BF, BBr and AlCl).

The Persistent Radical Effect in Organic Synthesis.

Radical-radical couplings are mostly nearly diffusion-controlled processes. Therefore, the selective cross-coupling of two different radicals is challenging and not a synthetically valuable transformation. However, if the radicals have different lifetimes and if they are generated at equal rates, cross-coupling will become the dominant process.

Electrochemical initiation of electron-catalyzed phenanthridine synthesis by trifluoromethylation of isonitriles.

The electron-catalyzed formation of phenanthridines starting from isonitriles initiated by an electrochemical reduction of the Togni reagent is presented. The required number of faradays per mole of starting material and the respective yields clearly show the catalytic character of the electron in this reaction. The mechanism is supported by cyclic voltammetry experiments.

Initiating radical reactions with non-thermal plasmas.

Non-thermal plasmas were used as radical initiators in three radical chain reactions: dehalogenation, 5-exo-trig cyclisation and trifluoromethylation with the Togni II reagent. The use of non-volatile solvents (or solvent-free conditions) gave high yields in all reactions under optimised conditions. Short reaction times and mild conditions make this method an attractive alternative to conventional radical initiators.

Iodinated (Perfluoro)alkyl Quinoxalines by Atom Transfer Radical Addition Using ortho-Diisocyanoarenes as Radical Acceptors.

A simple method for the preparation of functionalized quinoxalines is reported. Starting from readily accessible ortho-diisocyanoarenes and (perfluoro)alkyl iodides, the quinoxaline core is constructed during (perfluoro)alkylation by atom transfer radical addition (ATRA), resulting in 2-iodo-3-(perfluoro)alkylquinoxalines. The radical cascades are readily initiated either with visible light or by using α,α'-azobisisobutyronitrile (AIBN).

Radical perfluoroalkylation - easy access to 2-perfluoroalkylindol-3-imines via electron catalysis.

Arylisonitriles (2 equivalents) react with alkyl and perfluoroalkyl radicals to form 2-alkylated indole-3-imines via two sequential additions to the isonitrile moiety followed by homolytic aromatic substitution. The three component reaction comprises three C-C bond formations. The endocyclic imine functionality in the products is more reactive in follow up chemistry and hydrolysis of the exocyclic imine leads to 3-oxindoles that show fluorescence properties.

9-Silafluorenes via base-promoted homolytic aromatic substitution (BHAS)--the electron as a catalyst.

Transition-metal-free intramolecular radical silylation of 2-diphenylsilylbiaryls via base-promoted homolytic aromatic substitution (BHAS) to give 9-silafluorenes is reported. 2-Diphenylsilylbiaryls are readily prepared, and cross dehydrogenative silylation occurs with tert-butylhydroperoxide (TBHP) as a cheap stoichiometric oxidant in the presence of a small amount of tetrabutylammonium iodide (TBAI) as an initiator. These cyclizations are catalyzed by the electron.

6-Aroylated phenanthridines via base promoted homolytic aromatic substitution (BHAS).

Readily accessible 2-isocyanobiphenyls react with aromatic aldehydes via base promoted homolytic aromatic substitution (BHAS) to give 6-aroylated phenanthridines. Reactions occur via addition of acyl radicals to the isonitrile functionality and subsequent intramolecular BHAS of the intermediate imidoyl radicals. Initiation of the radical chain reaction is best achieved with small amounts of FeCl3 (0.

Cross dehydrogenative coupling via base-promoted homolytic aromatic substitution (BHAS): synthesis of fluorenones and xanthones.

Cross dehydrogenative coupling reactions occurring via base-promoted homolytic aromatic substitutions (BHASs) are reported. Fluorenones and xanthones are readily prepared via CDC starting with readily available ortho-formyl biphenyls and ortho-formyl biphenylethers, respectively. The commercially available and cheap tBuOOH is used as an oxidant.

Genotyping microarray for CSNB-associated genes.

Purpose: Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disease. Although electroretinographic (ERG) measurements can discriminate clinical subgroups, the identification of the underlying genetic defects has been complicated for CSNB because of genetic heterogeneity, the uncertainty about the mode of inheritance, and time-consuming and costly mutation scanning and direct sequencing approaches.

Methods: To overcome these challenges and to generate a time- and cost-efficient mutation screening tool, the authors developed a CSNB genotyping microarray with arrayed primer extension (APEX) technology.

Identification and functional characterization of a novel rhodopsin mutation associated with autosomal dominant CSNB.

Purpose: Mutations in RHO, PDE6B, and GNAT1 can lead to autosomal dominant congenital stationary night blindness (adCSNB). The study was conducted to identify the genetic defect in a large Swiss family affected with adCSNB and to investigate the pathogenic mechanism of the mutation.

Methods: Two affected cousins of a large Swiss family were examined clinically by standard methods: funduscopy, EOG, ERG, and dark adaptometry.

Night blindness-associated mutations in the ligand-binding, cysteine-rich, and intracellular domains of the metabotropic glutamate receptor 6 abolish protein trafficking.

Mutations in the GRM6 gene, which encodes the metabotropic glutamate receptor 6 (mGluR6), lead to autosomal recessive congenital stationary night blindness (CSNB), which is characterized by loss of night vision due to a defect in signal transmission from photoreceptor to the adjacent ON-bipolar cells in the retina. So far, the sequence variations that have been described in six different families include nonsense, frameshift, and missense mutations. Here we investigated the impact of missense mutations in the ligand-binding domain, a conserved cysteine-rich domain, and the intracellular domain on the localization of the protein.

[Arterial ocular occlusion associated with systemic venous thrombophilia--2 case reports].

Background: Arterial ocular occlusions in apparently healthy young men are unusual. Because of inconsistent study results there is a great amount of insecurity with respect to the reasonable diagnostic approach in such a scenario. We report on the process of diagnostic steps in two young men with arterial ocular occlusion such as non-arteritic optic neuropathy (NAION) and branch retinal arterial occlusion (BRAO).

LED-generated multifocal ERG on- and off-responses in complete congenital stationary night blindness -- a case report.

We report on the application of a light emitting diode (LED) screen to elicit multifocal ERG on- and off-responses in a patient presenting with the complete type of congenital stationary night blindness (cCSNB): A 63-years old woman was diagnosed with cCSNB by means of standard ERG procedures and dark adaptometry. To confirm this diagnosis and to investigate topographical differences of on- and off-responses a multifocal approach employing long-duration stimuli was added. Results of mfERG-testing were averaged in three groups (a central area of 7.

Correlation between central corneal thickness, applanation tonometry, and direct intracameral IOP readings.

Background: Several authors reported incorrect high intraocular pressure (IOP) values in eyes with a thick cornea using applanation tonometry. This hypothesis was checked by comparing applanation tonometry with direct intracameral manometry.

Methods: 73 patients, scheduled for intraocular surgery, were enrolled.