An asymmetric palladium-catalyzed conjugate addition reaction of arylboronic acids to enone substrates was investigated mechanistically. Desorption electrospray ionization coupled to mass spectrometry was used to identify intermediates of the catalytic cycle and delineate differences in substrate reactivity. Our findings provide evidence for the catalytic cycle proceeding through formation of a...

An asymmetric palladium-catalyzed conjugate addition reaction of arylboronic acids to enone substrates was investigated mechanistically. Desorption electrospray ionization coupled to mass spectrometry was used to identify intermediates of the catalytic cycle and delineate differences in substrate reactivity. Our findings provide evidence for the catalytic cycle proceeding through formation of a...

Imidazolium-based ionic liquids (ILs) serve both as recyclable reaction media and as precatalysts for the N-heterocyclic carbene-catalyzed conjugate addition of α,β-unsaturated aldehydes to chalcones. The reaction produces a broad scope of 1,6-ketoesters incorporating an anti-diphenyl moiety in high yields and with high stereoselectivity. In recycling experiments, the IL can be reused up to fiv...

protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and acetylenic esters, by nh-acids such as azathioprine, imidazole or theophylline leads to the formation of vinyltriphenylphosphonium salts, which undergo a michael addition reaction with a conjugate base to produce phosphorus ylides. silica nanoparticles (silica nps were prepared by therm...

We describe here the conjugate addition of tert-butyllithium to vinyl systems boronic esters generate a borata-alkene intermediate, followed by sequential SN2 reaction with alkyl halides, at room temperature. envisioned this goal through engaged C(sp3) chemical entities avoiding metal catalysts, additives, radical initiators or specific irradiation. This guarantees that new tetrasubstituted car...

A proposed rate-nephelometric inhibition immunoassay of phenytoin and phenobarbital in human serum involves the sequential addition to buffer of 42-microL aliquots of sample containing the hapten (drug) of interest, a hapten conjugate (drug-equine apoferritin), and specific antibody to the hapten. The drug and the drug conjugate compete for the binding sites on the antibody. The free hapten-ant...

The involvement of red blood cell spectrin in the ubiquitination process was studied. Spectrin was found to form two ubiquitin-associated derivatives, a DTT-sensitive ubiquitin adduct and a DTT-insensitive conjugate, characteristic intermediate and final products of the ubiquitination reaction cascade. In addition to spectrin and ubiquitin, ubiquitin-activating enzyme (E1) and ATP were necessar...

Short title: Inhibition of glutathione reductase by APAP-SG in vitro 2 Summary Acetaminophen is one of commonly used analgesics and antipyretics. It is a safe drug at therapeutic doses but in the overdose, it causes liver injury which may lead to acute liver failure. The aim of the present work was to investigate a new mechanism contributing to the toxic acting of acetaminophen especially to ex...

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and acetylenic esters, by NH-acids such as azathioprine, imidazole or theophylline leads to the formation of vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce phosphorus ylides. Silica nanoparticles (silica NPs were prepared by therm...