Extractive reaction for epoxidation of cyclohexene to cyclohexene oxide using dioxirane in ketone/Oxone® system

Cloisite 15Aº nanoclay as an effective PTC for the epoxidation of hydroxyl terminated polybutadiene (HTPB)

“…As the electron-rich double bonds attach to unstable electrophile three-member DMD rings, HTPB C=C bonds oxidized and HTPB converted to the to epoxidized HTPB. Recently, similar reaction mechanism has been reported by Kachasakul et al who used Oxone  as an oxidant in combination with tert-butyl ammonium persulfate as the PTC [16] .…”

“…In order to resolve the epoxidation reaction drawbacks, some experiments designed to epoxidize of double bonds by using in-situ generated dimethyl dioxirane (DMD) [15,16] . In-situ generated DMD is cyclic peroxide known as a powerful, reactive and useful oxidizing agent.…”

Chemoselective epoxidation of hydroxyl-terminated polybutadiene (HTPB) using in-situ generated dimethyl dioxirane (DMD)

“…These results confirm the high reactivity of cis double bonds in comparison with trans and vinyl; however, in the starting materials the trans content is high compared to cis. The low reactivity of the 1,2-vinyl microstructure is probably due to weak nucleophilicity of this group and can be obtained from 13 C-NMR spectra analysis, as shown in Figs 6 and 7.…”

“…Epoxidation of HTPB using the in situ-generated DMD/tetra-n-butyl ammonium bromide system is shown in Figs 1 and 2 [13].…”

“…The epoxidized HTPB was characterized by using 1 H-NMR, 13 C-NMR and FT-IR methods. The observed chemical shifts in 1 H-NMR and 13 C-NMR spectra of unepoxidized HTPBs are presented in Tables 1 and 2, and Figs 3 and 4, respectively. Our observations were similar to previously reported data [5].…”