Preparation, characterization and use of poly(4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid phase catalyst for acetylation of alcohols, phenols and amines

Magnetically recyclable silica-coated ferrite magnetite-K10 montmorillonite nanocatalyst and its applications in O, N, and S-acylation reaction under solvent-free conditions

Novel silica-coated ferrite nanoparticles supported with montmorillonite (K₁₀) have been prepared successfully by using a simple impregnation method. Further, these nanoparticles were characterized by using different analytical methods like FT-IR, PXRD, EDS, and FE-SEM techniques. In addition, these nanoparticles have been explored for their catalytic activity for the O, N, and S-acylation reactions under solvent-free conditions which gave moderate to excellent yields in a much shorter reaction time. Moreover, these nanoparticles could easily be separated out from the reaction medium after the reaction completion by using an external magnetic field and have been re-used for 10 cycles without any significant loss of the catalytic activity.

Novel silica-coated ferrite nanoparticles supported with montmorillonite (K₁₀) have been prepared and explored for their catalytic activity for the O, N, and S-acylation reactions under solvent-free conditions.

Cycloaddition of CO2 with epoxides and esterification reactions using the porous redox catalyst Co-POM@MIL-101(Cr)

The catalytic activity of the Co-POM@MIL-101(Cr) composite in solvent-free cycloaddition of CO₂ to epoxides and esterification of acetic acid with alcohols is due to an outer-sphere electron transfer mechanism using the Co(iii)/Co(ii) redox pair.

Ultrasound-assisted one-pot synthesis of substituted coumarins catalyzed by poly(4-vinylpyridinium) hydrogen sulfate as an efficient and reusable solid acid catalyst

Poly(4-vinylpyridinium) hydrogen sulfate solid acid was found to be efficient catalyst for synthesis of substituted coumarins via Pechmann reaction using ultrasound irradiation at room temperature and neat condition in high yields with short reaction times. This methodology offers momentous improvements over various options for the synthesis of coumarins with regard to yield of products, simplicity in operation and green aspects by avoiding toxic catalysts and solvents. Further, the catalyst can be reused and recovered for several times.