Activated carbon functionalized with Mn(II) Schiff base complexes as efficient alkene oxidation catalysts: Solid support matters

New Trends in Oxidative Functionalization of Carbon–Hydrogen Bonds: A Review

“…Consequently, the reaction proceeds without the participation of free radicals, unless it was proposed, for example, for an oxidation with hydrogen peroxide via hydroxyl radicals The so-called Shul'pin method [257][258][259] of analysis of oxygenates discussed above in this section and based on GC and PPh 3 has been used by other authors (selected examples are given in Refs. [260][261][262][263][264][265][266][267][268][269][270][271][272][273][274][275][276][277][278]). Finally, if the GC analysis shows that there is no difference between chromatograms obtained before and after reduction with PPh 3 , it indicates that the samples do not contain alkyl hydroperoxides.…”

Mn-Schiff base modified MCM-41, SBA-15 and CMK-3 NMs as single-site heterogeneous catalysts: Alkene epoxidation with H2O2 incorporation

“…Capitalizing our findings in catalytic oxidations, we point out that for successful H2O2 incorporation by grafted Mn-complexes, competitive H2O2 dismutation, by either the Mn-center or the inorganic support, should be minimized [32][33][34][35]. We have demonstrated also that the catalytic efficiency of such [Mn II -Schiff base] catalysts is switched-on by CH3COONH4 achieving remarkable effectiveness and selectivity towards epoxides [32][33][34][35].…”

“…However, very recently we have found that metalation of grafted ligands onto carbonbased supports results in totally inactive materials in catalytic epoxidations [35]. This was attributed to Mn II -spoliation by the free -COOH groups of the activated carbon support blocking the desirable Mn II -complexation with the grafted ligands in order to form the active catalytic centre [35]. Here to exclude such possibility when dealing with CMK-3, an alternative synthetic strategy was adopted which allowed the covalent grafting of the entire [Mn II -Schiff base] catalyst onto CMK-3 in one step (see Scheme 2).…”

“…Our group has developed synthetic strategies to prepare active [Mn II -Schiff base] oxidation catalysts covalently grafted onto silica-based [32][33][34] and carbon-based materials [35][36]. Capitalizing our findings in catalytic oxidations, we point out that for successful H2O2 incorporation by grafted Mn-complexes, competitive H2O2 dismutation, by either the Mn-center or the inorganic support, should be minimized [32][33][34][35].…”

Texture and surface chemistry of activated carbons obtained from tyre wastes

“…Mainly though, activated carbons have been used as adsorbents and catalysts [14][15][16][17][18][19].…”