Jasminaldehyde Synthesis Catalyzed by Al(Ga)PON Oxynitrides: Influence of the Reaction Conditions

Abstract

Nitridation of amorphous aluminium phosphate (AlPO4) and mixed aluminium gallium phosphate (Al0.5Ga0.5PO4) under ammonia flow allows preparing “AlPON” and “AlGaPON” bifunctional acid-base heterogeneous catalysts. Their acid-base bi-functional character allows their use as selective catalysts for the production of jasminaldehyde through the cross-condensation of heptanal and benzaldehyde, followed by the dehydration of the aldol intermediate product. Three parameters enabling to maximize the jasminaldehyde yields in a batch reactor operated at 125°C were investigated: the catalyst composition (Al/Ga and O/N ratio), the reactant concentration and the amount of catalyst in the reactor. Maximum jasminaldehyde selectivities were obtained for intermediate nitrogen contents (7-10 wt.%). Maximum reaction rates were obtained using pure reactants and a catalysts weight equal to 10% of the total reagent weight.

Aldol Condensations Using Bio-oil Model Compounds: The Role of Acid–Base Bi-functionality

“…It was also discovered that there was a decrease in selectivity to the cross condensation product with increased nitridation. Hasni et al [22] found that increased nitridation of their galloaluminophosphate material led to an increase in activity and in selectivity to the cross condensation product in the same reaction. However, there has been little investigation into the catalysis of aldol condensations involving the small aldehydes and ketones found in bio-oil and particularly not in the condensed phase, which will likely be required for bio-oil upgrading.…”

Synthesis of natural fragrance jasminaldehyde using silica-immobilized piperazine as organocatalyst

“…Once the proof-of-principle with silica-immobilized piperazine was successfully shown, in the next set of experiments the emphasis was put on optimizing both the conversion and selectivity of the reaction. Especially, to reach on-spec values for jasminaldehyde, a selectivity of 3 over by-product 4 (Scheme 1) must be higher than 90%, [16][17][18][19][20][21][22][23] and for obvious economic and technical reasons, a conversion higher than 90% is mandatory as well. Whereas for classic base-catalyzed processes reaching these optimized figures is more challengingdue to the high reactivity of such reaction systems -the use of heterogeneous catalysts should provide more controllable conditions.…”

“…adding heptanal stepwise to minimize secondary reactions), the use of heterogeneous catalysts such as solid acids, zeolites or aluminosilicates has been put forth. [16][17][18][19][20] However, the application of organocatalysis for the synthesis of jasminaldehyde has been rather scarce, with some few examples focusing on chitosan in different derivatized forms. [21][22][23] Aiming at combining heterogeneous organocatalysis, sustainable chemistry and application-driven catalysis, herein the use of silica-immobilized piperazine for the jasminaldehyde synthesis is reported for the first time.…”

Perovskites and metal nitrides as catalysts in the base-catalysed aldol addition of isobutyraldehyde to formaldehyde

“…With respect to metal nitrides, Bej et al 23 reported the application of molybdenum nitride as a catalyst in the gas phase aldol condensation of acetone. Hasni et al 24,25 discussed the oxynitride-catalysed aldol condensation of cyclopentanone with valeraldehyde and heptanal with benzaldehyde, respectively. Herein, we present the potential of perovskites and metal nitrides as solid bases, evaluating their catalytic performance in aldol addition of iBa to FA.…”