The first example of one-pot oxidative conjugate hydrothiocyanation-hydrosulfenylation of acrylic ester derived Baylis-Hillman alcohols, that is, methyl 3-aryl-3-hydroxy-2-methylenepropanoate, is reported. The reaction involves protic ionic liquid [Hmim]HSO4-mediated oxidation of Baylis-Hillman alcohols with NaNO3 to give methyl (E)-α-formylcinnamates followed by conjugate addition of sulfur-centered nucleophiles (NH4SCN/PhSH) to afford the corresponding methyl β-thiocyanato (or β-phenylsulfenyl)-α-formylhydrocinnamates diastereoselectively in 74-87% yields in a one-pot procedure. After isolation of the product, the ionic liquid [Hmim]HSO4 could be easily recycled for further use without any loss of efficiency.
本研究首次报道了
丙烯酸酯衍生的 Baylis-Hillman 醇(即 3-芳基-3-羟基-2-亚甲基
丙酸甲酯)的单锅氧化共轭氢
硫氰酸化-氢磺酰化反应。该反应涉及以 NaNO3 为介质的原
离子液体 [Hmim]HSO4 氧化 Baylis-Hillman 醇,生成 (E)-δ- 甲酰基
肉桂酸甲酯,然后共轭加入以
硫中心亲核物(NH4SCN/PhSH),以非对映选择性的方式得到相应的δ-
硫氰基(或δ-苯磺酰基)-δ-甲酰基氢
肉桂酸甲酯,一次反应的产率为 74-87%。分离出产物后,
离子液体 [Hmim]HSO4 可以很容易地回收再利用,而不会降低效率。