1. Hierarchical Beta zeolites as catalysts in a one-pot three-component cascade Prins–Friedel–Crafts reaction
- Author
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Roman Barakov, Maksym Opanasenko, Igor Bezverkhyy, Pavel S. Yaremov, Jiří Čejka, Nataliya D. Shcherban, Laboratoire Interdisciplinaire Carnot de Bourgogne [Dijon] (LICB), and Université de Bourgogne (UB)-Université de Technologie de Belfort-Montbeliard (UTBM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
010405 organic chemistry ,Ether ,010402 general chemistry ,Anisole ,01 natural sciences ,Pollution ,Environmentally friendly ,0104 chemical sciences ,Catalysis ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,chemistry.chemical_compound ,Adsorption ,chemistry ,Environmental Chemistry ,Organic chemistry ,Butyraldehyde ,Brønsted–Lowry acid–base theory ,Friedel–Crafts reaction ,ComputingMilieux_MISCELLANEOUS - Abstract
Hierarchical Beta zeolites obtained from concentrated reaction mixtures (H2O/Si = 2.5–7.0) in the presence of CTAB and their conventional and nanosponge analogues were investigated in a one-pot cascade environmentally friendly Prins–Friedel–Crafts reaction of butyraldehyde with 3-buten-1-ol and anisole under mild conditions (60 °C). The highest yields of the desired products with 4-aryltetrahydropyran structure were achieved when using hierarchical zeolites characterised by well-developed mesoporosity (facilitating the formation of bulky intermediates and products) and by an increased fraction of highly accessible (evaluated by TTBPy method) medium-strength Bronsted acid sites. Acid sites with higher strength promote strong adsorption of bulk O-containing intermediates or products and the formation of byproducts (tetrahydropyranyl ether and 2-propyloxan-4-ol). Therefore, this is an inexpensive and simple synthesis method for preparing hierarchical zeolites with catalytic activity comparable to that of nanosponge Beta, which is however prepared using complex and expensive multi-quaternary ammonium surfactants. Moreover, this synthetic protocol for 4-aryltetrahydropyrans replaces the carcinogenic and toxic chemicals, which have been previously used for Prins–Friedel–Crafts reactions, with green and non-toxic substances.
- Published
- 2020
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