Despite the previous literature describing the âlow-to-modestâ efficiency, the readily available C5-acetamide donor was reinvestigated for its use in α-sialylation under microfluidic conditions. The N-phenyltrifluoroacetimidate donor was efficiently mixed with an appropriate amount of TMSOTf to produce the α(2â6) and α(2â3)-sialylation products of galactose and glucosamine acceptors in excellent yields and with nearly perfect α-selectivity.
尽管之前的文献描述了 "低至最低 "的效率,但我们还是重新研究了在微流体条件下δ-ialylation中使用的现成的C5-乙酰胺供体。N- 苯基三
氟乙酰亚
氨酸供体与适量的 TMSOTf 有效混合后,可生成半
乳糖和
葡萄糖胺受体的δ(2â6)和δ(2â3)-
硅烷基化产物,产率极高,且具有近乎完美的δ选择性。