Greener and Efficient Epoxidation of 1,5-Hexadiene with tert-Butyl Hydroperoxide (TBHP) as an Oxidising Reagent in the Presence of Polybenzimidazole Supported Mo(VI) Catalyst

Abstract

Alkene epoxidation with TBHP as an oxidising reagent using heterogeneous Mo(VI) catalyst is an environmentally friendly process since it eliminates acid waste and chlorinated by-products often associated with the conventional industrial method that uses stoichiometric peracid such as peracetic acid and m-chloroperbenzoic acid. Polybenzimidazole supported Mo(VI) complex, i.e., PBI.Mo has been successfully prepared, characterised and assessed for the epoxidation of 1,5-hexadiene in the presence of tert-butyl hydroperoxide (TBHP) as an oxidising reagent. A quadratic polynomial model has been developed, demonstrating the yield of 1,2-epoxy-5-hexene in four independent variables. The effects of different parameters such as reaction temperature, feed mole ratio of 1,5-hexadiene to TBHP, catalyst loading, and reaction time were studied. Response surface methodology (RSM) using Box-Behnken Design (BBD) was employed to study the interaction effect of different variables on the reaction response. This study presents the optimization of 1,5-hexadiene epoxidation in a batch reactor using TBHP as an oxidant and a polymer-supported Mo(VI) catalyst.

Optimisation of greener and more efficient 1,7-octadiene epoxidation catalysed by a polymer-supported Mo(vi) complex via response surface methodology

“…9 Ambroziak et al 34 mentioned that increasing the feed molar ratio lowers the TBHP concentration to such an extent that it slows down the conversion of TBHP into epoxide. A similar feed molar ratio effect was reported in my previous published results; 35 it has been demonstrated that there was no significant difference in the rate of epoxidation when the feed molar ratio of 1,5-hexadiene to TBHP was increased from 2.5 : 1 to 10 : 1.…”

Production of fine chemicals using microporous and mesoporous heterogeneous catalysts

“…Such a drawback exists with almost all chemical reactions regardless of sector however, outlining the weighting of the benefits of using a polymer structure as a heterogeneous catalyst can possess over any negative aspects. Similar studies investigating the preparation of epoxides using a polybenzimidazolesupported Mo(VI) catalyst [200,201] produced similar results. Whilst the alkene being epoxidized varied between the studies, the findings illustrated that a polymer-based catalyst structure (in this case polybenzimidazole) is active in these reactions, and exhibits particularly high activity under reaction-specific optimized conditions.…”

A Comprehensive Review of Fine Chemical Production Using Metal-Modified and Acidic Microporous and Mesoporous Catalytic Materials

“…However, such a drawback exists for almost all chemical reactions regardless of sector, outlining the importance of weighing the benefits of using a polymer structure as a heterogeneous catalyst over any negative aspects. Similar studies investigating the preparation of epoxides using a polybenzimidazole-supported Mo(VI) catalyst [254,255] produced similar results. Whilst the alkene being epoxidised varied between the studies, the findings illustrated that a polymer-based catalyst structure (in this case, polybenzimidazole) is active in these reactions, and it exhibits particularly high activity under reaction-specific optimised conditions.…”