Synthesis and Biological Evaluation of O‐Methylated Glycolipids Related to PGLs via Direct Stereoselective Glycosidation and Sequential Suzuki–Miyaura Coupling using Boracyclane
作者:Ko Sato、Zakaria Omahdi、Kensuke Shibata、Koh‐hei Sonoda、Sho Yamasaki、Hiroshi Tanaka
DOI:10.1002/chem.201703684
日期:2017.11.16
methodology improved the efficiency of the synthesis of both PGL‐1 and PGL‐tb1 sugars. The process involved the formation of 2‐O‐naphthylmethyl‐α‐rhamnoside and 2‐O‐methyl‐α‐fucoside. Sequential Suzuki–Miyaura coupling using synthetic glycosides, boracyclane, and aryl bromides provided glycolipids related to PGL sugars, and was accomplished with a one‐pot process. Finally, we elucidated the immunosuppressive
报道了通过直接立体选择性糖苷合成的O-甲基化糖脂,其糖基与酚类糖脂(PGLs)中的糖基有关。用I 2和n Bu 4 NOTf处理2 - O-甲基鼠李糖苷酰亚胺可导致它们在低温下活化,并为α-鼠李糖苷提供出色的α-选择性。n Bu 4 NOTf增强了碘的亲电性。这种方法提高了PGL-1和PGL-tb1糖的合成效率。该过程涉及2 - O-萘甲基-α-鼠李糖苷和2- O的形成-甲基-α-岩藻糖苷。使用合成糖苷,硼环烷和芳基溴化物的顺序Suzuki-Miyaura偶联提供了与PGL糖相关的糖脂,并通过一锅法完成。最后,我们阐明所有这些合成的化合物的免疫抑制活性,发现苯基3- ö -α鼠李糖-2- ø -甲基- α鼠李糖苷具有一个6-(2-萘基)己基表现最强的抑制效果。