Continuous Synthesis of Epoxides from Alkenes by Hydrogen Peroxide with Titanium Silicalite‐1 Catalyst Using Flow Reactors

Abstract

Abstract. Continuous‐flow epoxidation of aliphatic and aromatic alkenes with hydrogen peroxide (H2O2) was carried out to give epoxides using a fixed‐bed liquid flow reactor equipped with a solid titanium silicalite‐1 (TS‐1) catalyst column. The developed flow reaction enables continuous synthesis of 4‐phenyl‐1,2‐epoxybutane from 4‐phenyl‐1‐butene in 90%–98% yields (22.4 g) for 150 h from a catalyst column of 5 mm inner diameter with 100 mm length. Employment of a mixed solution of MeCN and MeOH with preservation of the Ti active site in TS‐1 crystal structures with few defects permits continuous epoxidation of less‐reactive long‐chain terminal alkene and multifunctional alkene to give epoxides in 12%–98% yields with 78%–99% selectivity.magnified image

Effectiveness of sulfuric acid and hydrochloric acid catalysts in the esterification of frankincense cinnamic acid with ethanol and methanol

“…The weakness of sulfuric acid as a catalyst is that if the acylation substrate contains alkenes, it can cause side reactions, namely becoming epoxides, diols and cleaving to carbonyls, so that it does not produce optimal esters (Wang et al, 2023;Kon et al, 2023). In this study, the effectiveness of sulfuric acid and hydrochloric acid catalysts was studied in esterification by acylating cinnamic acid isolated from frankincense (Chehri et al, 2018).…”