Magnetic decorated 5-sulfosalicylic acid grafted to chitosan: A solid acid organocatalyst for green synthesis of quinazoline derivatives

Magnetic DL-methionine grafted to chitosan by EDTA linker nanomaterial: a highly efficient multifunctional organocatalyst for the synthesis of highly substituted imidazole derivatives under green conditions

“…6, two weight loss steps were observed between 250 and 400°C. Since the pristine chitosan is degraded at 200-220°C 23 , This degradation at the temperature range of 250-400°C indicates that DL-methionine is grafted properly to the chitosan backbone through EDTA linker, which affects the thermal stability of the chitosan and its degradation takes place at a higher temperature. Another weight loss can be seen from 400-500°C, which is related to the total decomposition of the polymeric chain and carbon residue.…”

“…Nanomaterials are being explored and utilized across various sectors such as biomedicine and nanomedicine, energy storage and transformation, environment remediation and water puri cation, catalysis, etc [1][2][3][4][5] . In this context, nano-ordered catalytic systems have received great interest in recent years due to their high activity resulting from high surface to volume ratio and appropriate dispersion of active sites, shape-selectivity and quantum size effect as well as the ability to be recycled and reused repetitively to address the gap between the classic homogenous and bulk heterogeneous catalysts and making a bridge between these active research elds 4,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] . This impact can be intensi ed when biopolymers and their modi ed forms, as the heterogeneous version of organocatalysts, come to play and add more advantages to the designed nano-ordered catalytic systems in terms of zero or low toxicity as well as their biodegradability after retirement 21,[26][27][28][29][30][31][32] .…”