- Epoxidation of Primary and Secondary Alkenylammonium Salts with Dimethyldioxirane, Methyl(trifluoromethyl)dioxirane, and m-Chloroperbenzoic Acid. A General Synthetic Route to Epoxyalkylamines
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Selective syn-epoxidation of C=C double bonds in primary and secondary alkenylammonium arenesulfonate salts 3H(+), to give the corresponding epoxyalkylammonium salts 4H(+), has been achieved by reaction with electrophilic O-transfer reagents such as m-CPBA, methyl(trifluoromethyl)dioxirane (TFDO), and dimethyldioxirane (DMDO).Epoxyalkylamines 4 are easily obtained in high yields from the corresponding epoxyalkylammonium salts 4H(+) by simple deprotonation with sodium carbonate.The ammonium group deactivates the C=C double bond, and hence the epoxidation rate is slower than in the case of simple olefins.H-Bonding interaction between the ammonium group and the O-transfer reagent (m-CPBA and DMDO) in the transition state is claimed to account for the rate enhancement and diastereoselectivity observed when the necessary conformational requirements are established.The allylic ammonium group is shown to be very efficient in directing the epoxidation with m-CPBA and DMDO on the syn-diastereoface.
- Asensio, Gregorio,Mello, Rossella,Boix-Bernardini, Carmen,Gonzalez-Nunez, Maria Elena,Castellano, Gloria
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- CATALYST FOR SYNTHESIZING ETHYLENIMINE AS WELL AS PREPARATION METHOD AND APPLICATION THEREOF
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The present invention relates to a catalyst for synthesizing ethylenimine as well as a preparation method and application thereof. The related catalyst comprises a carrier and metal ions loaded on the carrier; the carrier is a composite oxide comprising titanium, silicon and phosphorus elements; the metal ions are magnesium ions, iron ions and cesium ions; the molar ratio of the magnesium ions to the iron ions to the cesium ions is (1-10):1:0.1; the mass of all metal ions is 0.5-10 percent of that of the carrier. In the related preparation method, a catalyst precursor is roasted at the temperature of 350-650° C., so that the catalyst is obtained; the catalyst precursor is the mixture of the carrier, soluble salt of magnesium, soluble salt of iron and soluble salt of cesium. The present invention also provides the application of the catalyst to synthesis of the ethylenimine by using amino alcohol as the raw material. Compared with a common catalyst which has the requirement on the temperature of over 400° C., the catalyst of the present invention obviously reduces the reaction temperature. The prepared catalyst can catalyze the intramolecular dehydration reaction of the amino alcohol and has relatively excellent selectivity.
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Paragraph 0043
(2016/11/17)
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