[reaction: see text]. We describe a superior procedure for the catalytic, asymmetric synthesis of beta-lactams using a bifunctional catalyst system consisting of a chiral nucleophile and an achiral Lewis acid.

We have reported the fabrication of boric acid incorporated into surface of magnetite nanoparticles. The catalyst was characterized using spectroscopic, magnetic and thermal techniques (FT-IR, SEM, XRD, ICP, VSM and TGA). It catalyzed Mukaiyama aldol reaction of a ketene silyl acetal type nucleophile ((1-methoxy-2-methylprop-1-enyloxy) trimethylsilane), and various aldehydes (aromatic, aliphati...

The strong Brønsted and Lewis acid sites are active in the tandem conversion of levulinic into ethyl valerate. intrinsic activity former is more significant Pd/HBEA catalyst deactivation partially reversible by calcination.

Two types of general and practical enantioselective catalysts, namely, bimetallic complexes and Lewis acid-Lewis base bifunctional catalysts were developed based on the concept of multifunctional catalysis. In the first part of this review, the first example of a catalytic enatioselective nitro-Mannich reaction as well as a direct catalytic enantioselective aldol reaction of 2-hydroxyacetopheno...

The catalytic activity was enhanced by the introduction of C18PA on support Ru/Nb 2 O 5 catalyst. addition more Lewis acid sites activated aromatic ring in phenol and promoted formation cyclohexanol.

Lewis acidic zeolites are used to synthesize unsaturated dicarboxylic acid esters via aldol condensation of keto esters. Hafnium-containing BEA (Hf-BEA) zeolites catalyze the condensation of ethyl pyruvate into diethyl 2methyl-4-oxopent-2-enedioate and diethyl 2-methylene-4oxopentanedioate (an itaconic acid ester analogue) with a selectivity of ca. 80% at ca. 60% conversion in a packed-bed reac...

In order to use H2 as a clean source of electricity, prohibitively rare and expensive precious metal electrocatalysts, such as Pt, are often used to overcome the large oxidative voltage required to convert H2 into 2 H(+) and 2 e(-). Herein, we report a metal-free approach to catalyze the oxidation of H2 by combining the ability of frustrated Lewis pairs (FLPs) to heterolytically cleave H2 with ...

We present a new microencapsulated catalyst and report its use in a tandem multicatalyst reaction. Using an encapsulation technique, we developed an active, site-isolated amine catalyst that is capable of catalyzing the addition of nitromethane to an aldehyde. When a second Lewis acid catalyst is added, the nitroalkene intermediate is trapped and converted to the corresponding Michael adduct. W...

A general asymmetric Strecker-type reaction is reported, catalyzed by the Lewis acid-Lewis base bifunctional catalyst 1. The reaction of trimethylsilyl cyanide (TMSCN) with various fluorenyl imines, including n-aldimines and alpha,beta-unsaturated imines, proceeds with good to excellent enantioselectivities in the presence of a catalytic amount of phenol as additive (20 mol%) (catalytic system ...

An approach for the control and understanding of supported molecular catalysts is demonstrated with the design and synthesis of open and closed variants of a grafted Lewis acid active site, consisting of Al(III)-calix[4]arene complexes on the surface of silica. The calixarene acts as a molecular template that enforces open and closed resting-state coordination geometries surrounding the metal a...