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...

Abstract The palladium-catalysed Suzuki–Miyaura cross-coupling reaction of organohalides and organoborons is a reliable method for carbon–carbon bond formation. This involves base-mediated transmetalation process, but the presence base also promotes competitive protodeborylation. Herein, we established via Lewis acid-mediated an organopalladium(II) intermediate with organoborons. Experimental t...

Dimerisation of alpha-olefins by a catalyst system comprising of a bis(imido) tungsten compound and a Lewis acid component has been investigated by density functional theory employing a catalyst model that closely mimics the real system together with ethylene chosen as a prototypical substrate. This study disclosed that the Lewis acid preferably forms four-membered chelates by bridging across t...

Activity coefficients at infinite dilution of some common solvents in a protic ionic liquid ethylammonium nitrate have been measured using well established gas-chromatography-method. This method was possible to apply due to extremely low vapour pressure of ethylammonium nitrate at temperatures below 100 °C. Activity coefficients and separation factors were compared with those for aprotic ionic ...

Bis(diphenylthiophosphoryl)amine, a weak protic acid, can be readily deprotonated. The alkali salts [Ph2P(S)]2NM have been used to prepare S-bonded complexes with transition metals containing a NP2S2M six membered ring [1]. Although the struc­ tures of the neutral ligand [Ph2P(S)]2NH [2] and of several transition metal complexes [1] have been de­ termined by X-ray diffraction techniques, struct...