Selective oxidation of cyclohexene through gold functionalized silica monolith microreactors

Abstract

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. were found to be catalytically inactive with Au being the minimum necessary requirement for the reaction to proceed. The impregnated Au-containing monolith was found to be less active than the thiol functionalized Au-containing material, attributable to the low metal surface area of the Au nanoparticles. The reaction on the thiol functionalized Au-containing monolith was found to depend strongly on the type of oxidant used: tert-butyl hydroperoxide (TBHP) was more active than H 2 O 2, likely due to the thiol induced hydrophobicity in the monolith.

Recent advances on controllable and selective catalytic oxidation of cyclohexene

“…b Without parentheses: isolated yield of 6; Inside parentheses: GC yield of 6. microreactors. After thiol modification, both the cyclohexene convention and hex-2-en-1-one 6 selectivity were largely improved (Table 2, entries 12 vs. 11) [42]. The reactions were tested with H2O2 as a cleaner oxidant, but the cyclohexene conversion dramatically decreased (3% vs. 18% with t-BuOOH) [42].…”

Ruthenium-doped Titania-pillared Clay for The Selective Catalytic Oxidation of Cyclohexene: Influence of Ru Loading

“…Ti-PILC micrograph shows large particles with smooth surfaces coexisting with fine grains probably TiO2. Whereas, micrographs of the supported Ti-pillared materials shows a homogeneous distribution of small grains covering completely the clay surface [56]. EDX microanalysis shows the structural elements of clay, namely silicon and aluminum.…”

Diverse Supports for Immobilization of Catalysts in Continuous Flow Reactors

“…Catalysts could be bonded on the backbones of monolithic materials via a rich array of interactions (Figure 5c), for example covalent bonds, [53][54][55] coordination interactions, [56,57] inorganic replica [58] and specific absorptions. [59,60] Smarsly and coworkers [54] reported the immobilization of (3-aminopropyl)trimethoxysilane (APTMS) onto self-prepared silica monoliths and its application as a heterogeneous catalyst in the Knoevenagel condensation between cyano ethylacetate and various aromatic aldehydes under continuous-flow conditions.…”

“…The system was then explored in the continuous‐flow via catalytic partial hydrogenation reaction of 3‐halogeno‐nitrobenzenes and 3‐hexyn‐1‐ol in the liquid phase, showing remarkable conversions and selectivity under very mild conditions. In addition, Au NPs have been incorporated in mesoporous silica monoliths by either direct impregnation during the formation of the monolith or by functionalization of the monolith with thiol groups prior to incorporation of Au NPs, [57] with the latter displaying catalytic activity in a superior way. Alumina‐grafted silica monoliths were also constructed [58] as solid Lewis acid catalysts for flow Diel‐Alder reactions.…”