Proline‐based polymeric monoliths: Synthesis, characterization, and applications as organocatalysts in aldol reaction

Abstract

Proline-based polymer monoliths were synthesized via green protocol using lipase-catalyzed esterification of methacrylic acid and 4-hydroxyproline. Prolinyl methacrylate thus prepared was polymerized in situ as crosslinked monolith. The monolith was characterized by various techniques such as Fourier transform infrared, 1 H-NMR, 13 C-NMR, scanning electron microscopy (SEM), X-ray diffraction (XRD), and nitrogen analysis and used as catalyst in aldol reactions. The swelling behavior of the monolith was also studied as function of various external parameters like pH and temperature. The monoliths synthesized with 1% crosslinker was selected as candidate monolith for use as catalyst in aldol reaction, which was studied as a function of time, temperature, substrate structure, and amount of water:EtOH. The catalysts exhibited high efficiency in the cross aldol reaction, especially with the aromatic substrates having electron withdrawing substituent, and also good activity retention was observed when recycleability was studied up to five cycles.

Three‐Dimensional Printing of Methacrylic Grafted Cellulose Nanocrystal‐Reinforced Nanocomposites With Improved Properties

“…After modification, some new chemical shift peaks appear on the basis of the characteristic chemical shift absorption peak of CNC, which means the successful modification of CNC. These new peaks at around 164, 135, and 126 ppm attributed to C7, C8, and C9 carbon atoms resonances of the groups of the methacrylic molecule grafted onto the unmodified CNC, respectively .…”

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

“…Biochemical methods based on lipases in organic solvents for chemoselective acylation of peptides have been developed for a number of years [ 106 ]. Also within organocatalysis, which has been an important arena for the advancement of acidic O -acylation techniques, chemoselective lipase-catalyzed esterification of hydroxyproline with methacrylic acid has been reported [ 107 ]. However, the practicality of this biochemical method appears limited in a preparative context.…”