Pt/CeO2 with residual chloride as reusable soft Lewis acid catalysts: Application to highly efficient isomerization of allylic esters

Phthalimide-N-sulfonic acid and Isatin-N-sulfonic acid as highly efficient catalysts for the synthesis of bis-coumarins

Two highly efficient protocols for the production of bis-coumarins under solvent-free conditions have been introduced. The reaction of 4-hydroxycoumarin (2 eq.) with arylaldehydes (1 eq.) using phthalimide-N-sulfonic acid (PhtSA) or isatin-N-sulfonic acid (IsSA), as solid-acid catalysts, afforded the mentioned compounds with good to excellent yields in short times.Briefly, we have introduced tw...

Highly selective Lewis acid sites in desilicated MFI zeolites for dihydroxyacetone isomerization to lactic acid.

Desilication of commercial MFI-type (ZSM-5) zeolites in solutions of alkali metal hydroxides is demonstrated to generate highly selective heterogeneous catalysts for the aqueous-phase isomerization of biobased dihydroxyacetone (DHA) to lactic acid (LA). The best hierarchical ZSM-5 sample attains a LA selectivity exceeding 90 %, which is comparable to that of the state-of-the-art catalyst (i.e.,...

Multi-wall Carbon Nanotubes Supported Molybdenum Acetylacetonate: Efficient and Highly Reusable Catalysts for Oxidation of Sulfides with Tert-butyl Hydroperoxide

In the present work, highly efficient oxidation of sulfides catalyzed by MoO2(acac)2 supported on multi-wall carbon nanotubes, MWCNTs, modified with 1,2-diaminobenzene (DAB) and 2-aminophenol (AP), at room temperature are reported. The effects of various parameters such as reaction time, solvent, catalyst amount, oxidant, etc, were studied. These heterogenized catalysts showed high activity in ...

Chiral magnesium(II) binaphtholates as cooperative Brønsted/Lewis acid-base catalysts for the highly enantioselective addition of phosphorus nucleophiles to α,β-unsaturated esters and ketones.

A little cooperation goes a long way: The cooperative Brønsted/Lewis acid-base supramolecular catalysts formed in situ from simple chiral magnesium(II) binaphtholate aqua complexes promoted the highly enantioselective 1,4-hydrophosphinylation of α,β-unsaturated esters with diaryl phosphine oxides and 1,2-hydrophosphonylation of α,β-unsaturated ketones with dialkyl phosphites (see scheme).

Heteroatom-Substituted Delaminated Zeolites as Solid Lewis-Acid Catalysts