The selective one-step access to fluoroalkylated hexestrol derivatives, nonsteroidal estrogens, is achieved in good excellent isolated yields under organophotoredox conditions by using the stable and easy handle Langlois reagent. Furthermore, challenging hydrotrifluoromethylation of styrenes proceeds mild reaction without requirement for any additive. We assume that solvent drives pathway towar...

The first radical intermediate in the thiourethane-mediated deoxygenation of an alcohol (Barton-McCombie reaction) can participate in an exo-hex-5-enyl- or exo-hept-6-enyl-type radical cyclization when a suitable radical acceptor (e.g., alpha,beta-unsaturated ester, oxime ether, or hydrazone) is appropriately placed. Carbohydrate-derived imidazolyl and triazolyl thiourethanes with such acceptor...

With NADPH as the electron donor, rat liver NADPH cytochrome P-450 reductase (NADPH:ferricytochrome oxidoreductase, EC 1.6.2.4) catalyzes the single-electron reduction of several quinone antibiotics to a semiquinone or free radical state. The benzanthraquinones adriamycin, daunorubicin, carminomycin, 7-O-methylnogalarol, and aclacinomycin A and the N-heterocyclic quinones streptonigrin and mito...

The B2 subunit of ribonucleotide reductase from Escherichia coli contains a tyrosine radical which is essential for enzyme activity. In the reaction between ribonucleotide reductase and the substrate analogue 2'-azido-2'-deoxycytidine 5'-diphosphate a new transient radical is formed. The EPR characteristics of this new radical species are consistent with a localization of the unpaired electron ...

Single electron transfer (SET)-triggered radical ion-based reactions have proven to be powerful options in synthetic organic chemistry. Although unique chain processes have been proposed in various photo- and electrochemical radical ion-based transformations, the turnover number, also referred to as catalytic efficiency, remains unclear in most cases. Herein, we disclose our investigations of r...

Mild treatment with trypsin causes a radical change in the heavy meromyosin (HMM) binding properties of intermediate filaments in glycerinated, myosin-extracted cultured chick embryo connective tissue cells. In non-trypsin-treated cells, HMM labeling of filaments was often indistinct and variable in its distribution. By contrast, in cells treated with trypsin (under conditions which allowed mos...

Seven-membered lactones undergo selective SmI2 -H2 O-promoted radical cyclization to form substituted cyclooctanols. The products arise from an exo-mode of cyclization rather than the usual endo-attack employed in the few radical syntheses of cyclooctanes. The process is terminated by the quenching of a chiral benzylic samarium. A labeling experiment and neutron diffraction study have been used...

The stability of the α-nitronyl nitroxide radical unit under acidic conditions is investigated by an integrated experimental UV/Vis spectroscopy and TDDFT study. In the field of molecular magnetism, α-nitronyl nitroxide radicals are important as purely organic spin carriers due to their synthetic versatility. Here, the existence of an intermediate of the protonated α-nitronyl nitroxide radical ...

Herein we present the first example of aryl radical formation via the visible light-mediated decarboxylation of aryl carboxylic acids using photoredox catalysis. This method constitutes a mild protocol for the decarboxylation of cheap and abundant aryl carboxylic acids and tolerates both electron-rich substrates and those lacking ortho-substitution. The in situ formation of an acyl hypobromite ...

The synthesis of alkyl boronic esters by direct decarboxylative radical addition of carboxylic acids to vinyl boronic esters is described. The reaction proceeds under mild photoredox catalysis and involves an unprecedented single-electron reduction of an α-boryl radical intermediate to the corresponding anion. The reaction is amenable to a diverse range of substrates, including α-amino, α-oxy, ...