A mild promoter such as Yb(OTf)3 allows selective activation of glycosyl trichloroacetimidate building blocks in the presence of glycosyl (N-phenyl)trifluoroacetimidates with a similar pattern of protecting groups. This selectivity has been exploited in the one-pot assembly of two different trisaccharides in good overall yields. In contrast to other reported procedures, a catalytic amount of promoter is sufficient to trigger both glycosidation steps of the sequential process.
温和的
促进剂如Yb(OTf)3可以在具有类似保护基团的糖基(N-苯基)三
氟乙
酰亚胺存在下,选择性地激活糖苷三
氯乙
酰亚胺构建块。这种选择性已被利用于一锅法合成两种不同的三糖,且整体产率良好。与其他报告的程序相比,催化剂的微量即可触发顺序过程中的两个糖苷化步骤。