The Synthesis Of Nitrone Intermediates Based On Sulfoxonium Ylides And The Corresponding Cycloaddition With Alkenes/Alkynes

Up to now,nitrogen-containing heterocyclic compounds have been playing a more and more important role in the fields of biological,pharmaceutical and chemical industries,attracting the majority of scientists to conduct continuous and all-round researches.Among them,the pentacyclic compounds and the smallest heterocyclic compounds,such as isooxazolidines and aziridines,not only are found in a wide range of natural products,but also are the core blocks of many chemical drugs.For the above reasons,the paper mainly studies a convenient,rapid and efficient construction of the two kinds of compounds.Two main parts of the content are shown as follows:1.Synthesis of isoxazolidines via catalyst-free one-pot three-component cycloaddition of sulfoxonium ylides,nitrosoarenes and alkenes.The optimal reaction conditions were obtained by single factor variable method.On the basis,45 kinds of isoxazolidines were produced with the highest yield of 98% and the highest diastereoselectivity was up to 7:1.Then the reaction mechanism was studied by control experiments with a possible reaction path proposed.Finally,satisfactory results were achieved by figuring out the scale-up test and the further applied study of isoxazolidines.2.Catalyst-free three-component synthesis of polysubstituted aziridines from sulfoxonium ylides,nitrosoarenes and alkynes.The optimal reaction conditions were obtained by single factor variable method.29 kinds of aziridiens were then obtained under the optimized conditions with the highest yield of 89%and the highest diastereoselectivity ratio of 6.6:1.The detailed mechanism was achieved through controlling experiments.To explain the difference of selectivity,a possible reaction path was proposed.To our delight,the scale-up experiment and the ring opening reaction of aziridines were put forward with satisfactory data.