Remote Activation of Disarmed Thioglycosides in Latent-Active Glycosylation via Interrupted Pummerer Reaction
作者:Xiong Xiao、Yueqi Zhao、Penghua Shu、Xiang Zhao、Yan Liu、Jiuchang Sun、Qian Zhang、Jing Zeng、Qian Wan
DOI:10.1021/jacs.6b08305
日期:2016.10.12
yields. Meanwhile, observation of thiosulfinate, thiosulfonate, and disulfide suggested that the leaving group was activated via an interrupted Pummerer reaction. The disarmed SPSB thioglycosyl donors could be selectively activated in the presence of various thioglycosides with remote activation mode. Finally, two natural hepatoprotective glycosides, Leonoside E and Leonuriside B, were efficiently synthesized
S-糖苷,即 S-2-(2-丙硫基) 苄基 (SPTB) 糖苷,通过简单的选择性氧化被转化为相应的氧化糖基供体 S-2-(2-丙基亚磺酰基) 苄基 (SPSB) 糖苷。用三氟甲磺酸酐处理解除武装的 SPSB 供体和各种受体,以良好到极好的产率提供所需的糖苷。同时,对硫代亚磺酸盐、硫代磺酸盐和二硫化物的观察表明离去基团是通过中断的普默勒反应激活的。解除武装的 SPSB 硫糖基供体可以在各种硫糖苷的存在下以远程激活模式被选择性地激活。最后,使用这种新开发的方法以收敛的方式有效地合成了两种天然的保肝糖苷,Leonoside E 和 Leonuriside B。