Magnetic nanoparticles have emerged recently as an alternative for the easy separation of nanosized catalysts from reaction mixtures by employing an external magnetic field. These magnetic nanoparticles have been used as supports for catalysts and/or as part of an active catalytic site. Herein, special attention is given to identify the main synthetic steps required to develop both precious‐ and nonprecious‐metal‐catalyzed CC and CX coupling reactions by using magnetically separable catalysts.

Novel ionic liquid derived ordered mesoporous carbons functionalized with sulfonic acid groups IOMC-ArSO3H and GIOMC-ArSO3H were prepared, characterized, and examined in the dehydration reaction of fructose into 5-hydroxymethylfurfural (5-HMF) both in aqueous and nonaqueous systems. To study and correlate the surface properties of these carbocatalysts and some other SBA-15 typed solid acids with 5-HMF yield, hydrophilicity index (H-index) were employed in the fructose dehydration. Our study systematically declared that almost a criterion may be expected for application of solid acids in which by increasing H-index value up to 0.8 the HMF yield enhances accordingly. More increase in H-index up to 1.3 did not change the HMF yield profoundly. Although, it has been shown that the catalyst with larger H-index (∼1.3) resulted in higher activity both in aqueous and 2-propanol systems, during the recycling process deactivation occurs because of more water uptake and the catalysts with optimum amount of H-index (∼0.8) is more robust in the dehydration of fructose.

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The application of a number of mesoporous sulfonic acids including MCM-41-PrSO 3 H (1a), MCM-41-Ph-PrSO 3 H (1b), SBA-15-PrSO 3 H (2a), SBA-15-Ph-PrSO 3 H (2b), SBA-15-EtPhSO 3 H (3a), and SBA-15-Ph-EtPhSO 3 H (3b) with different surface hydrophobicity in acid-catalyzed dehydration of fructose into 5hydroxymethylfurfural (HMF) in a water-nitromethane solvent mixture was investigated. Among the studied mesoporous solid acids, the catalysts with lower surface hydrophobicity and relative acidity were found to be more selective and efficient catalytic system for HMF production. Our studies showed that the hydrophilic surface of the employed solid acids might indeed provide a means of faster departure of HMF from the system mesopores as soon as it forms, thus retarding the rehydration of HMF to unwanted by-products and improving the HMF selectivity. HMF selectivity of 75% was reached in 93% fructose conversion in a water-NM system at 140 C within 30 min in the presence of catalyst 2a, which is comparable or even superior to other systems which employ MIBK-2-butanol or other organic cosolvents.

We herein report an unprecedented integrated process using organic salts as bifunctional organocatalysts under absolutely metal-free conditions for the conversion of a wide range of biomass-derived carbohydrates, cellulose, and even untreated lignocellulose (e.g. straw and barley husk) into 5-hydroxymethylfurfural (5-HMF).