tion of SiO2 with pending nitrile functions (SiO2 @CN) followed by CN hydrolysis. All complexes and silica beads have been characterized by NMR, infrared, DLS, TEM, X-ray diffraction. The replacement of CH3 COOH by SiO2 @COOH (one hundred times significantly less on molar ratio) has been evaluated for (ep)oxidation on many substrates (cyclooctene, cyclohexene, cyclohexanol) and discussed with regards to activity and green metrics. Keywords: manganese complexes; iron complexes; oxidation; epoxidation; functionalized silica beads; H2 O2 ; replacement of volatile reagent1. Introduction The synthesis of epoxides/ketones is definitely an exciting analysis field from the basic to the applicative point of view in organic synthesis or catalysis. Indeed, these organic compounds could be obtained working with really basic organic oxidants (but quite tedious inside the post-treatment process) like meta-chloroperbenzoic acid (m-CPBA) [1,2], NaIO4 [3], RCO3 H [4]. They could also be obtained applying metal catalysts plus the use of an organic solvent is extremely generally needed [7]. It could be the case with a number of Mo complexes [104]. The usage of chlorinated solvents for example dichloroethane (DCE), a hugely toxic solvent, has to be avoided [15]. In the study group, the processes have already been identified to be active without having organic solvent working with complexes with tridentate ligands [160] or polyoxometalates (POMs) [213], giving a very first step towards a cleaner method. The oxidant utilized within this case is tert-butyl hydroperoxide (TBHP) in aqueous solution. In terms of atom economy, the epoxidation reaction could be improved working with H2 O2 because the oxidant. Selective epoxidation reactions have been achieved working with (BPMEN)Mn(OTf)two [246], (BPMEN)Fe(OTf)two or (Me2 PyTACN)Fe(OTf)2 [275] as catalysts (BPMEN = N,N -dimethyl-N,N -bis(pyridin2-ylmethyl)ethane-1,2-diamine, Me2 MGAT2 Synonyms PyTACN = 1,4-dimethyl-7-(2-pyridylmethyl)-1,4,7triazacyclononane), applying H2 O2 as oxidant in acetonitrile as the organic solvent with higher selectivity towards epoxides when acetic acid is added as co-reagent [36,37]. Certainly, by blocking among the two labile web pages around the metal center, the access to cis-diols isn’t probable [36,37]. Additionally, acting as a proton relay, the carboxylic acid protonates the distal oxygen from the metal-hydroperoxo intermediate, favoring the heterolytic O-O bond cleavagePublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.Copyright: 2021 by the PI3Kγ manufacturer authors. Licensee MDPI, Basel, Switzerland. This article is definitely an open access article distributed beneath the terms and circumstances of the Inventive Commons Attribution (CC BY) license ( creativecommons.org/licenses/by/ four.0/).Molecules 2021, 26, 5435. doi.org/10.3390/moleculesmdpi/journal/moleculesMolecules 2021, 26,2 ofand major to the clean formation of a metal-oxo compound, an intermediate accountable for the selective oxidation of your olefin into epoxide [37,38]. When BPMEN is employed as ligand, a higher quantity of acetic acid is used (14 equiv. vs. substrate), using a volume comparable to the among the organic solvent engaged inside the reaction. An elegant strategy to replace the organic volatile carboxylic acid by recoverable objects could possibly be the use of a strong reagent with COOH pending functions [392]. For this, it was exciting to use the possibility on the functionalization of silica–using trialkoxysilane precursors–to acquire pending acidic functions on silica [436]. Silica was employed previously for diverse uses, in particular to graft,