The FeII complexes of two isomeric pentadentate bispidine ligands in the presence of H2O2 are catalytically active for the epoxidation and 1,2-dihydroxylation of cyclooctene (bispidine = 3,7-diazabicyclo[3.3.1]nonane; the two isomeric pentadentate bispidine ligands discussed here have two tertiary amine and three pyridine donors). The published spectroscopic and mechanistic data, which include ...

A new method to rapidly generate pyrrolidines via a SOMO-activated enantioselective (3 + 2) coupling of aldehydes and conjugated olefins has been accomplished. A radical-polar crossover mechanism is proposed wherein olefin addition to a transient enamine radical cation and oxidation of the resulting radical furnish a cationic intermediate which is vulnerable to nucleophilic addition of a tether...

Radically complex: The photolytic reaction of [Cp*P{W(CO)(5)}(2)] (Cp* = C(5)Me(5)) with a diphosphene produces, via a radical intermediate, an air-stable complexed triphosphaallyl radical, in which the unpaired electron is evenly distributed over both terminal P atoms. Oxidation of the radical leads to a triphosphaallyl cation, which is only stable at low temperatures in solution, whereas the ...

[reaction: see text] Photochemical irradiation of crystalline (2R,4S)-2-carbomethoxy-4-cyano-2,4-diphenyl-3-butanone 1 led to highly efficient decarbonylation reactions. Experiments with optically pure and racemic crystals showed that the intermediate radical pairs undergo a highly diastereo- and enantiospecific radical-radical combination that leads to the formation of two adjacent stereogenic...

The biologically important redox couple, /I-nicotinamide adenine dinucleotide/l,4,/%dihydronicotinamide adenine dinucleotide, provides a grossly reversible prototype system for an overall electrode reaction consisting of two successive one-electron (1 e) transfer steps coupled with (a) dimerization of an intermediate free radical product, (b) protonation-deprotonation of an intermediate product...

INTRODUCTION To review the current status of laparoscopic radical prostatectomy (LRP) and robotic assisted radical prostatectomy (RALP) in relation to radical retropubic prostatectomy (RRP) in the management of localized prostate cancer. MATERIALS AND METHODS Between 1982 and 2007 published literature was reviewed using the National Library of Medicine database and the following key words: re...

Cataractous and noncataractous human lenses were irradiated with ultraviolet (UV) light, and the resulting triplet and radical species were studied by electron paramagnetic resonance spectroscopy. Evidence is presented that free radicals are produced by a biphotonic process involving tryptophan as an intermediate triplet. This makes free radical production energetically feasible. A possible lin...

A transition-metal-free carboxyamidation process, using aryl diazonium tetrafluoroborates and isocyanides under mild conditions, has been developed. This novel conversion was initiated by a base and solvent induced aryl radical, followed by radical addition to isocyanide and single electron transfer (SET) oxidation, affording the corresponding arylcarboxyamide upon hydration of the nitrilium in...

Electron paramagnetic resonance and electrochemistry are used to evidence the interaction between 1,10-phenanthroline (Phen) and KO(t)Bu to form the 1,10-phenanthroline radical anion, Phen˙(-), and the (t)BuO˙ radical via an inner-sphere electron transfer. In addition, electrochemistry is also used to explain the formation of aryl radicals from aryl bromides via outer-sphere electron transfer f...