This perspective summarizes the catalytic activity of K10 montmorillonite as a multifunctional catalyst for organic reactions.

A material based on palladium nanoparticles supported on nitrogen rich mesoporous covalent organic polymers exhibiting excellent catalytic activity towards Mizoroki–Heck cross coupling reaction.

CaY, activated under different conditions, was characterized with 1H, 31P, and 1H/27Al double resonance MAS NMR. The 1H MAS NMR spectra of CaY, calcined in an oven at 500 °C, shows resonances from H2O (bound to Ca2+ and the zeolite framework), CaOH+, aluminum hydroxides, silanols, and Brønsted acid sites. No evidence for Lewis acidity is observed on adsorption of trimethylphosphine, and an estimate of ≈16 Brønsted acid sites per unit cell is obtained for this sample. CaY activated in an oven at higher temperatures contains less water, but all the other species are still present. In contrast, CaY activated by slow ramping of the temperature under vacuum to 500 or 600 °C shows a much lower concentration of Brønsted acid sites (<1/unit cell). Again, no evidence for Lewis acidity was observed. These NMR results have been utilized to understand the very different product distributions that are observed for reactions of 1,1- and 1,2-diarylethylenes in zeolite CaY activated in an oven (in air) and under vacuum. Samples with high concentrations of Brønsted acid sites react stoichiometrically with these sites, yielding diarylalkanes. At low concentrations, the Brønsted acid sites can act catalytically resulting in isomerization reactions.

A simple and efficient route for the synthesis of 5-substituted 1H-tetrazoles catalyzed by CoY zeolite is reported. The salient features of this atom-economical, cost-effective, and high-yield cobalt-catalyzed protocol are aerobic conditions, lower reaction time, and milder reaction conditions without additives. Other advantages include experimental ease of manipulation, safer alternative to hazardous, corrosive, and polluting conventional Lewis acid catalysts, recovery, and reusability with consistent catalytic activity. The results are rationalized by proposing a suitable mechanism.

The kinetics of oxygenation of several para-substituted phenyl methyl sulfides and sulfoxides with a series of 5-substituted and sterically hindered oxo(salen)chromium(V) complexes have been studied by a spectrophotometric technique. Though the reaction of sulfides follows simple second-order kinetics, sulfoxides bind strongly with the metal center of the oxidant and the oxygen atom is transferred from the oxidant-sulfoxide adduct to the substrate. The reduction potentials, E(red), of eight Cr(V) complexes correlate well with the Hammett sigma constants, and the reactivity of the metal complexes is in accordance with the E(red) values. The metal complexes carrying bulky tert-butyl groups entail steric effects. Organic sulfides follow a simple electrophilic oxidation mechanism, and the nonligated sulfoxides undergo electrophilic oxidation to sulfones using the oxidant-sulfoxide adduct as the oxidant. Sulfoxides catalyze the Cr(V)-salen complexes' oxygenation of organic sulfides, and the catalytic activity of sulfoxides is comparable to pyridine N-oxide and triphenylphosphine oxide. The rate constants obtained for the oxidation of sulfides and sulfoxides clearly indicate the operation of a pronounced electronic and steric effect in the oxygenation reaction with oxo(salen)chromium(V) complexes.

A versatile three‐component coupling of aldehydes, alkynes and amines has been developed, catalyzed by Ni2+‐exchanged Y‐zeolite, which acts as an environmentally benign, recyclable, efficient and heterogeneous catalyst. This three‐component (A3) coupling (reported for the first time to proceed under nickel catalysis) is carried out under solvent‐free conditions, and the corresponding propargylamines are obtained in good to excellent yields.

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A template consisting of a melamine‐based microporous polymer network was synthesized and utilized as a solid support to stabilize palladium nanoparticles; the resulting Pd/SNW1 material showed good catalytic activity in copper‐free Sonogashira coupling in water. Various aryl iodides were efficiently coupled with arylacetylenes under very low catalyst loadings in an environmentally benign medium. Hot filtration tests confirmed the heterogeneity of the catalyst, which was reused under the optimized conditions without any significant change in its activity. This simple preparation of the catalyst, the stability of the catalyst, product selectivity, and easy recovery and regeneration indicate the possible utilization of this catalytic system in a multitude of catalyzed reactions and industrial processes.