Oxygen transfer reactions from an Oxaziridinium tetrafluoroborate salt to Olefins
作者:Xavier Lusinchi、Gilles Hanquet
DOI:10.1016/s0040-4020(97)00890-9
日期:1997.10
Oxaziridinium efficiently epoxidises olefins. It reacts as an electrophilic reagent and does not transfer its oxygen to deactivated double-bonds or carbonyl functions. Epoxidation of cyclic allylic acetates shows a remarkable diastereoselectivity leading to the syn isomer. We propose that the epoxidation reaction proceeds through a one-step process.
Organic thiol metal-free stabilizers and plasticizers for halogen-containing polymers
申请人:Starnes Herbert William
公开号:US20050049307A1
公开(公告)日:2005-03-03
Organic thiol compounds based on pentaerythritol and dipentaerythritol are described herein. More specifically, the compounds of the present invention are mixed esters of pentaerythritol and dipentaerythritol having at least one sulfhydryl group and preferably a plurality of sulfhydryl groups as well as at least one non-thiol-containing group. The organic thiol compounds are utilized to plasticize and/or heat stabilize halogen-containing polymer compositions especially poly(vinyl chloride) compositions. The compositions are substantially free or free of metal-based stabilizers, Lewis acids and terpenes. The compounds of the present invention are ideally utilized in polymers normally susceptible to deterioration and color change which can occur during processing of the polymer or exposure of the polymer to certain environments and surprisingly also serve as excellent plasticizers.
Competitive Reactions of Diene Cation Radicals Formed on Irradiated Metal Oxide Surfaces
作者:Marye Anne Fox、Debra D. Sackett、Janet N. Younathan
DOI:10.1016/s0040-4020(01)90277-7
日期:1987.1
which involves the intermediacy of a diene cationradical generated by transfer of an electron from the adsorbed diene to a photogenerated hole localized at the surface of the excited TiO2 particle. Non-oxidative cleavage products are also observed, and the effect of the semiconductor surface in controlling reactivity of the photogenerated cationradical is discussed. The first examples of aromatization
1,1,2,2‐Tetrahydroperoxy‐1,2‐diphenylethane was used for the efficient and metal‐free epoxidation of various α,β‐unsaturated ketones, carried out under mild alkaline conditions at room temperature.
A series of α,β-unsaturatedketones has been treated with sodium perborate in water and 1,4-dioxane under microwave irradiation to produce α,β-epoxyketones in good yields.