“Ring Opening–Ring Closure” Strategy for the Synthesis of Aryl-<i>C</i>-glycosides
作者:Chen-Fu Liu、De-Cai Xiong、Xin-Shan Ye
DOI:10.1021/jo500730y
日期:2014.5.16
new “ring-opening–ring closure” strategy for the synthesis of aryl-C-glycosides was described. This strategy exploited the nickel-catalyzed regioselective β-O elimination of glycals by reactions with various aryl boronic acids or potassium aryltrifluoroborates to yield the ring-opened products, which underwent the Lewis acid, protonic acid, PhSeCl, or NBS mediated ring closure reactions to afford diverse
对于芳基的合成一个新的“开环型环密封塞”的策略Ç -glycosides被描述。该策略通过与各种芳基硼酸或芳基三氟硼酸钾反应来开发镍催化的区域选择性β-O消除糖基来产生开环产物,该产物经历了路易斯酸,质子酸,PhSeCl或NBS介导的闭环反应,从而形成了开环产物。提供多样化的芳ç -glycosides。筛选路易斯酸和质子酸后,发现从开环底物开始,Ph 3 PHBr或Sc(OTf)3介导的闭环反应提供了α-或β-偏爱的芳基-C - Δ2 。 3-糖苷分别。此外,β- d苯基Ç -glycosides成功经由PhSeCl介导的环化反应来制备,而α- d苯基Ç糖苷被经由NBS介导的环化反应而获得。除去2-取代官能由卜后3 SNH / AIBN,的2-脱氧-芳基-合成Ç -glycosides最终被实现以立体选择性方式进行。