ZnO modified ZSM-5 and Y zeolites are synthesized by performing atomic layer deposition (ALD) of ZnO to HZSM-5 and HY using diethyl zinc and water as the precursors. The surface area and pore volume of ZSM-5 and Y zeolites are progressively reduced with the increasing number of ZnO ALD cycles. XRD and SEM characterization methods show that highly dispersed ZnO species are deposited on the inter...

Microspectroscopic methods were explored to investigate binder effects occurring in ZSM-5-containing SiO2- and Al2O3-bound millimetre-sized extrudates. Using thiophene as a selective probe for Brønsted acidity, coupled with time-resolved in situ UV/Vis and confocal fluorescence microspectroscopy, variations in reactivity and selectivity between the two distinct binder types were established. It...

The combined acid catalyzed hydration of alkynes is an efficient one-step synthesis of carbonyl compounds. This atom-economical method is effective with a wide range of substrates, and the products are obtained in very good yields with low catalyst loading (0.2%). Furthermore, solid acids like Nafion were also efficient and could be easily recycled multiple times without loss of reactivity.

Bi(OTf)(3)·nH(2)O was found to be an efficient promoter of the cyclisative hydroamination of unactivated alkenyl sulfonamides, giving rise to the N-protected 2-methyl pyrrolidines in good to excellent yields (up to 95%). Based on control experiments, a joint Lewis acid-Brønsted acid catalysis might be in operation, or triflic acid itself, generated in situ by hydrolysis of metal triflate, could...

Photocatalytic reactions of enones using metal polypyridyl complexes proceed by very different reaction manifolds in the presence of either Lewis or Brønsted acid additives. Previous work from our lab demonstrated that photocatalytic [2+2] cycloadditions of enones required the presence of a Lewis acidic co-catalyst, presumably to activate the enone and stabilize the key radical anion intermedia...

In the course of developing an enantioselective, Lewis base/Brønsted acid co-catalyzed carbosulfenylation of alkenes, a seemingly impossible conundrum arose: How could a catalyst inhibit a stoichiometric reaction? Despite the observation of very good enantioselectivities, the rate of the uncatalyzed reaction (i.e., no Lewis base) was found to be comparable to or slightly faster than that of the...