An investigation on the stereoselective cascade sulfa-Michael/aldol reaction of nitroalkenes and commercially available 1,4-dithiane-2,5-diol to 3,4,5-substituted tetrahydrothiophenes, bearing a quaternary stereocenter, is presented. A secondary amine thiourea derived from (R,R)-1,2-diphenylethylamine was found to be the most effective catalyst when using trans-β-methyl-β-nitrostyrenes affording the heterocyclic products in good yields and moderate stereoselectivities.
一项关于立体选择性串联磺酰-迈克尔/醛缩反应的研究结果被提出,该反应以硝基烯烃和市售的1,4-二硫代醚-2,5-二醇为底物,生成带有季碳立体中心的3,4,5-取代四氢噻吩。当使用反式-β-甲基-β-硝基苯乙烯时,由(R,R)-1,2-二苯乙胺衍生的二级胺硫脲被发现是最有效的催化剂,产物收率良好,立体选择性适中。