A chromium-catalyzed pinacol-type cross-coupling reaction between alpha,beta-unsaturated carbonyl compounds and aldehydes is reported. Even sterically demanding substrates could be coupled to afford the corresponding pinacols in good yields. Systematic studies concerning the origin of the diastereoselectivities led to the proposal of a mechanism for this synthetically useful reaction. Acroleins...

Submit Manuscript | http://medcraveonline.com carbonic acid derivatives is a method frequently used for the synthesis of pyrimidines and 1,3-thiazines [1-7]. Although these methods have been mentioned in the literature for a long time, there are only a few examples of investigation on the mechanism and the stereochemistry of reactions. Based on earlier examinations [5-7] reaction of α,β-unsatur...

Five-membered nitrogen heterocycles such as g-lactams and pyrroles are found in various natural products and pharmaceuticals. Construction of these skeletons in a simple and efficient manner is one of the most important topics in synthetic organic chemistry. In this context, the development of a novel synthetic approach for g-aminocarbonyl compounds composed of a secondary or primary amine moie...

In this study, twelve neuraminidase (NA) inhibitory compounds 1-12 were isolated from heartwood of Caesalpinia sappan on the basis of their biological activities against three types of viral NAs. Of isolated homoisoflavonoids, sappanone A (2) showed the most potent NAs inhibitory activities with IC(50) values of 0.7 µM [H1N1], 1.1 µM [H3N2], and 1.0 µM [H9N2], respectively, whereas saturated ho...

Aldehydes are electrophilic compounds to which humans are pervasively exposed. Despite a significant health risk due to exposure, the mechanisms of aldehyde toxicity are poorly understood. This ambiguity is likely due to the structural diversity of aldehyde derivatives and corresponding differences in chemical reactions and biological targets. To gain mechanistic insight, we have used parameter...

Extended enolates, particularly dienolates, may be generated upon deprotonation of α,β(and most usually β,γ)-unsaturated carbonyl compounds by treatment with base. While known for more than half a century, their use in catalytic asymmetric bond-forming reactions has remained underdeveloped until recently. The Minireview M. Oiarbide and C. Palomo on page 10226 highlights the reactivity selectivi...

An electrophilic, coordinatively unsaturated rhodium complex supported by borate-linked oxazoline, oxazoline-coordinated silylene, and N-heterocyclic carbene donors [{κ(3)-N,Si,C-PhB(Ox(Me2))(Ox(Me2)SiHPh)Im(Mes)}Rh(H)CO][HB(C6F5)3] (, Ox(Me2) = 4,4-dimethyl-2-oxazoline; Im(Mes) = 1-mesitylimidazole) is synthesized from the neutral rhodium silyl {PhB(Ox(Me2))2Im(Mes)}RhH(SiH2Ph)CO () and B(C6F5...

α,β-Unsaturated ketones and aldehydes have been synthesized from their corresponding silyl enol ethers in a straightforward protocol involving a visible-light promoted organocatalytic, aerobic oxidation reaction. A cheap organic dye was used catalytically in these reactions as the photosensitizer.

Owing to their inherent features like smaller size and higher surface area exposed reactants, iron oxide nanoparticles have gained enormous interest are extensively used as magnetically recyclable catalysts for various organic reactions. Herein, we report highly hydrophilic, non-aggregated, strongly positively charged (ζ potential: + 45.7 mV) ultra-small cerium cations/complexes- stabilized mag...