Polyvinylpolypyrrolidone-bound boron trifluoride (PVPP-BF3); a mild and efficient catalyst for synthesis of 4-metyl coumarins via the Pechmann reaction

Abstract

Polyvinylpolypyrrolidone-supported boron trifluoride has been studied for synthesis of 4methyl coumarin by the Pechmann reaction. The reaction proceeded smoothly with hydroxyl phenols and ethyl acetoacetate in good yields in ethanol at reflux conditions. The polyvinylpolypyrrolidone-boron trifluoride complex is a non-corrosive and stable solid catalyst elevated Lewis acid property.

One-flow synthesis of tetrahydrocannabinol and cannabidiol using homo- and heterogeneous Lewis acids

“…In an attempt to further raise the yields, we changed to the boron trifluoride resins, as the corresponding catalyst is known to be effective in homogeneous flow reactions [33][34][35]. Interestingly, while pumping the substrate solution through the reactor, a red colour was observed (see: supporting information II).…”

Recent Advances in Synthetic Applications of Polyvinylpyrrolidone Supported Reagents and Catalysts

“…of the polyvinylpolypyrrolidone-bound boron trifluoride (PVPP-BF 3 ) as a stable polymeric Lewis acid catalyst in some organic reactions such as synthesis of amides by the reaction of nitriles with benzhydrol and tertiary alcohols or tert-butyl acetate via Ritter reaction (Scheme 12) [15,16], the acylation of alcohols, phenols and trimethylsilyl ethers with acetic anhydride (Scheme 13) [17], the synthesis of coumarins via Pechmann condensations of phenols with ethyl acetoacetate (Scheme 14) [18], the synthesis of 14-aryl-14H-dibenzo [a,j] xanthenes and bis(naphthalen-2-yl-sulfane) derivatives (Scheme 15) [19], the synthesis of 1,8-dioxooctahydroxanthenes and 1,8-dioxodecahydroacridines via condensation of aromatic aldehydes and dimedone in acetonitrile at room temperature, and aromatic aldehydes, dimedone, and aromatic amines in acetonitrile at 80 °C respectively (Scheme 16) [20], the oxidation of aldehydes to carboxylic acids and oxidative esterification of benzaldehydes in the presence of 35% hydrogen peroxide (Scheme 17) [21] and the oxidation of sulfides to sulfones in the presence of 35% hydrogen peroxide at room temperature (Scheme 18) [22]. Excellent yields, easy work-up and reusability and stability of the catalyst are some advantages of these methods.…”

Polyvinylpolypyrrolidone Supported Brønsted Acidic Catalyst for Esterification

“…Recently, its application in catalyst field has drawn much attention because it has many advantages such as being insoluble in all kinds of solvents and nontoxic. Mokhtary and Najafizadeh [21] used PVPP supported boron trifluoride as the catalyst to prepare N-tertbutyl amides by reaction of nitriles with tert-butyl acetate. They found that PVPP supported boron trifluoride was a high efficient Lewis acid.…”