A binary catalyst system for the enantioselective bromocycloetherification of 5-arylpentenols is described. The combination of an achiral Lewis base and a chiral Brønsted acid affords good enantioselectivities for the cyclization of Z configured 5-arylpentenols to form bromomethyltetrahydrofurans. The constitutional site selectivity is highly dependent upon the aromatic substituent and the conf...

The polyetherification of diols with 4-12 methylene units was studied in Brønsted Acid Ionic Liquids (BAILs). High molar mass poly(oxyalkylene)s were obtained at relatively low temperatures (130 °C), except in the cases of 1,4-butanediol and 1,6-hexanediol where cyclic ether formation was observed.

Alcohol is key: regio- and enantioselective hydroamination of 1,3-dienes has been achieved with the dinuclear catalyst (R)-DTBM-SEGPHOS. The rate and selectivity of the reaction are enhanced by alcohol additives like menthol, which coordinates the cationic gold(I) to generate a Brønsted acid that can participate in catalysis. Mbs=p-methoxybenzenesulfonyl.

The first highly enantioselective hydrogenation of simple indoles was developed with a Brønsted acid as an activator to form the iminium intermediate in situ, which was hydrogenated using Pd(OCOCF(3))(2)/(R)-H8-BINAP catalyst system with up to 96% ee. The present method provides an efficient route to enantioenriched 2-substituted and 2,3-disubstituted indolines.

Brønsted or Lewis acid assisted activation of an imidogold precatalyst (L-Au-Pht, Pht = phthalimide) offers a superior way to generate cationic gold compared with the commonly used silver-based system. It is also broadly applicable for most common gold-catalyzed reactions. For reactions that require milder conditions, milder acids can be used for optimized efficiency.

The first catalytic asymmetric Piancatelli reaction is reported. Catalyzed by a chiral Brønsted acid, the rearrangement of a wide range of furylcarbinols with a series of aniline derivatives provides valuable aminocyclopentenones in high yields as well as excellent enantioselectivities and diastereoselectivities. The high value of the aza-Piancatelli rearrangement was demonstrated by the synthe...

A multicomponent organocatalyzed highly diastereo- and enantioselective synthesis of CF(3)-substituted aziridines is described. This reaction of in situ generated CF(3)CHN(2) and aldimines was realized by chiral Brønsted acid catalysis. The utility of the products is illustrated by easy access to β-CF(3) isocysteine and aziridine-containing dipeptides.

A novel palladium-catalyzed intramolecular reductive amination of ketones with weakly nucleophilic sulfonamides has been developed in the presence of a Brønsted acid, giving a wide range of chiral γ-, δ-, and ε-sultams in high yields and up to 99% of enantioselectivity.

the silica boron sulfuric acid nanoparticles (sbsans) as an efficient heterogeneous solid acid catalyst with both brønsted and lewis acidic sites catalyzed the preparation of bis-4-hydroxycoumarin derivatives using reaction of aldehydes and 4-hydroxycoumarin under mild and solvent-free condition at room temperature. this new and efficient methodology has advantages in comparison with currently ...

The catalytic activity of oxide-supported vanadium oxide is improved by the presence of tungsten oxide for the selective catalytic reduction of nitric oxides. We propose a mechanism for V−W synergy through studies of the reduction−oxidation behavior of near-monolayer VOX and WOX species grown by atomic layer deposition on the α-Al2O3 (0001) single crystal surface. In situ X-ray standing wave me...