Organoammonium salts composed of a Brønsted acid and an anilinothiourea promoted the Michael addition of ß-keto esters and α,ß-unsaturated aldehydes in the presence of primary amines to give functionalized 1,4-dihydropyridines enantioselectively. With the use of the different Brønsted acids such as DFA and HBF(4) with the same bifunctional thiourea, both enantiomers of 4-substituted 1,4-dihydro...

This review describes the development in the use of Au(I)/Brønsted acid binary catalytic systems to enable an enantioselective transformation in one-pot that cannot be achieved by gold catalysts alone. The examples discussed herein are promising since apart from using chiral ligands there exists a possibility of using chiral Brønsted acids. Clearly, the horizon for enantioselective gold catalys...

Palladium(II)-catalyzed aerobic oxidative amination of styrene with oxazolidinone proceeds with catalyst-controlled regioselectivity: (CH3CN)2PdCl2 (1) and (Et3N)2PdCl2 (2) catalyze formation of the anti-Markovnikov and Markovnikov enecarbamate products, 3 and 4, respectively. Kinetic studies and deuterium kinetic isotope effects demonstrate that these two reactions possess different rate-limit...

A zirconium modified MCM-48 mesoporous material was synthesized by surfactant-templated method. Surface grafting Zr-MCM-48 with tungstophosphoric acid led to a great enhancement of both the number of the Brønsted acid sites and acidity strength in comparison with the bare support. At 100 ̊C, the 30 wt% H3PW12O40/Zr-MCM-48 contained 174 mol/g Brønsted acid sites which were 21.7 times greater tha...

For the selective catalytic reduction of NOx with NH3 (NH3-SCR) reaction, how to precisely adjust reducibility and surface acidity over SCR catalysts remains a fundamental challenge. Here, very facile effective way, addition WOx species using an incipient wetness impregnation method, balance redox acidic properties CeOx for optimizing its performance was proposed. Especially, nanopolyhedron pre...

Light alkene oligomerization on heterogeneous acidic catalysts is widely and successfully used in current commercial processes. However, ethylene remains inefficient due to ethylene’s inability form reaction intermediates a sufficient extent acid sites. Adding Ni(II) solid acids can more efficiently catalyze selectively produce butenes fuel range products. The review proposes complete detailed ...