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The effects of solid acids as cocatalysts on the chelation-assisted hydroacylation of alkenes and alkynes

The use of homogeneous Bronsted acid cocatalysts (such as benzoic acid) in hydroacylation reactions via imine intermediates has been extensively studied, but the use of heterogeneous cocatalysts has been limited to montmorillonite K10. Thus, we can use other solid acids to increase the efficiency of the reaction. Here, we described the effects of sulfated zirconia, Al-MCM-41 or superacid modified montmorillonite on the hydroacylation of alkenes and alkynes with aldehydes via imine intermediates and in the presence of the Wilkinson complex. Furthermore, we addressed the dual role of montmorillonite, a redox reagent in the presence of TEMPO and an acid solid, allowing the direct use of benzyl alcohols as substrates to generate saturated or a-b unsaturated ketones

Synthesis of Cycloveratrylene Macrocycles and Benzyl Oligomers Catalysed by Bentonite under Microwave/Infrared and Solvent-Free Conditions

Tonsil Actisil FF, which is a commercial bentonitic clay, promotes the formation of cycloveratrylene macrocycles and benzyl oligomers from the corresponding benzyl alcohols in good yields under microwave heating and infrared irradiation in the absence of solvent in both cases. The catalytic reaction is sensitive to the type of substituent on the aromatic ring. Thus, when benzyl alcohol was substituted with a methylenedioxy, two methoxy or three methoxy groups, a cyclooligomerisation process was induced. Unsubstituted, methyl and methoxy benzyl alcohols yielded linear oligomers. In addition, computational chemistry calculations were performed to establish a validated mechanistic pathway to explain the growth of the obtained linear oligomers

Childhood asthma outcomes during the COVID-19 pandemic: Findings from the PeARL multi-national cohort

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