Density functional theory (DFT) (Becke3LYP functional and the D95 basis set) was used to study the influence of substitution on the dimethyldioxirane epoxidation reaction of six- and seven-membered cyclic enol ethers. In agreement with our previously reported experimental results, the calculations predict that substitution on the cyclic enol ether influences the level of diastereoselectivity. A...

We use atomistic computer simulation techniques to investigate the site partitioning of iron in (Mg,Fe)SiO 3 perovskites. Our calculations predict that the most energetically favourable reaction for iron substitution will be a direct exchange ofFe 2+ for Mg 2+. Substitution f Fe into the octahedral site and Si into the 8-12 fold coordinated site, as proposed by Jackson et al. [1987], is predict...

With a miniaturized (3 microL volume) fiber-optics based system for on-line measurement by UV/Vis spectroscopy, the reaction rate constants (at different pressures) and the activation volumes (deltaV(not =)) were determined for a nucleophilic aromatic substitution and an aza Diels-Alder reaction in a capillary microreactor.

NMR studies of (13)C/(12)C isotopic patterns in Cu(iii) intermediates and reaction products together with DFT calculations of possible reaction pathways indicate an intermolecular S(N)2 like substitution mechanism for ligand exchange reactions in square planar Cu(iii) complexes, which is proposed to be slow compared to reductive elimination at synthetic conditions.

An efficient solvent free reaction of 1-chloro-2-nitrobenzene with anilines to give N-substituted nitro anilines by nucleophilic aromatic substitution in good to excellent yields has been described. The effect of different salts on the reaction has also been studied.

An intramolecular enantioselective metal-catalyzed dearomatization reaction is described. This procedure allows the dearomatization of naphthalene derivatives through an electrophilic aromatic substitution-type reaction on a Pd(II) intermediate. The high yields and enantioselectivities achieved make this procedure a valuable method for synthetic chemists.

Treatment of meso 2-ethylhexyl-3-mercaptopropionate substituted porphyrins with base at room temperature generated a porphyrin thiolate anion which in situ reacted in a nucleophilic aromatic substitution (SNAr) reaction with remaining thioether derivative. This reaction yielded S-linked bisporphyrins in good yields, with mechanistic insight obtained via displacement reactions. Additionally, SNA...

Me(3)SiI-promoted reaction of salicylic aldehydes with β-dicarbonyl compounds provided a facile way to construct 4H-benzopyrans in moderate to good yields. This tandem reaction proceeds with high efficiency through nucleophilic addition, silyl enol ether formation, substitution, reduction, and intramolecular nucleophilic cyclization.

We report an enantioselective approach to tertiary α-chloro esters through the reaction of silyl ketene acetals and N-chlorosuccinimide. The reaction is promoted by a chiral squaramide catalyst, which is proposed to engage both reagents exclusively through non-covalent interactions. Application of the tertiary chloride products in stereospecific substitution reactions is demonstrated.

Highly efficient and eco-friendly protocol for the synthesis of bis(3-indolyl)methanes by the electrophilic substitution reaction of indole with aldehydes catalyzed by poly(4-vinylpyridinium)hydrogen sulfate was described. Excellent yields, shorter reaction times, simple work-up procedure, avoiding hazardous organic solvents, and reusability of the catalyst are the most obvious advantages of th...