A heterogeneous organocatalyst for olefin epoxidation

Organocatalytic activation of hydrogen peroxide: towards green and sustainable oxidations

“…Having established an organocatalytic approach in a series of organic transformations, Kokotos and coworkers expanded their strategy in investigating the use of 2,2,2-triuoroacetophenone (3) towards the epoxidation reaction of unactivated alkenes (Scheme 8). 20 The authors employed an extremely low catalyst loading (up to 5 mol%) of ketone 3, which was found to be capable of promoting with ease the selective epoxidation of various mono-, di-and trisubstituted alkenes and known natural compounds, such as limonene (21 and 22) or cholesterol (23) in excellent yields (up to 99%) combining short reaction times (Scheme 8). This was a major improvement, compared to the state of the art at that time.…”

“…Inspired by Kokotos' work on organocatalytic alkene epoxidation, Tyablikov and coworkers developed a heterogenous catalyst, where the 2,2,2-triuoroacetophenone moiety of 3 was embedded in SBA-15 mesoporous silica, in their effort to prepare a catalyst that can be easily recycled. 23 Furthermore, two different research groups 24,25 sought to harness this protocol, for large-scale reactions. Employing continuous-ow reactor apparatus, Zheng and coworkers improved mass and heat transfer rates.…”

Selective propylene epoxidation in liquid phase using highly dispersed Nb catalysts incorporated in mesoporous silicates

“…Metal incorporated mesoporous materials have shown promising features in the area of heterogeneous catalysis of olefin epoxidation due to their remarkable catalytic properties and relatively cheaper precursors compared with those for TS-1 catalyst preparation [50][51][52][53][54][55][56][57][58][59][60][61][62][63]. For example, Ti modified MWW zeolite shows N 99% selectivity to PO and 95% H 2 O 2 efficiency during propylene epoxidation [40,64].…”