New organic-inorganic LDH composites: Synthesis, characterization and catalytic behavior in the green epoxidation of a, ß-unsaturated esters

New organic-inorganic based LDH composites have been prepared using different methodologies, ie the ion-exchange method (Org@LDH-exch), the reconstruction (Org@LDH-mem) and the direct intercalation (Org@LDH-inter) method, respectively. Irrespective of the procedure, the -C=O group of levulinate moiety was envisaged as a potential active organocatalyst in the epoxidation of trans-methylcinnamate to methyl-phenyl-glycidate. The characterisation of these materials through adsorption-desorption isotherms of nitrogen at −196 °C, XRD, TG-DTA and DRIFT confirmed a successful intercalation only for Org@LDH-inter. The reactions were carried out via in situ generated dioxiranes using levulinate as active organocatalyst and H2O2/acetonitrile mixture as oxidant. Intercalated levulinate in aminoterephthalate/LDH structure led to conversions up to 25% with a total selectivity to methyl-phenyl-glycidate. Besides this, the heterogeneous organocatalyst behave as a green system: the constitutive levulinic acid represents one of the most important renewable platform molecules, while replacing the Oxone reagent with the more benign hydrogen peroxide and the substitution of an inorganic soluble base with the basic function of the LDH-support afford a more benign system.