Transition-Metal-Free β-Selective C-Glycosylation of β-Glycosyl Boronates via Stereoretentive 1,2-Migration
Transition-Metal-Free β-Selective C-Glycosylation of β-Glycosyl Boronates via Stereoretentive 1,2-Migration
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通过立体保留 1,2-迁移对 β-糖基硼酸酯进行无过渡金属 β-选择性 C-糖基化
作者：
Yoritate Makoto;Hirai Go;Yasutomi Hiroki;Takeda Daiki;Higashibayashi Shuhei;Sugai Takeshi
天然聚糖的C-糖苷类似物由于其对细胞糖苷水解酶的抗性而成为药物化学和化学生物学中有用的分子工具。我们以前报道了2-脱氧-β-糖基硼酸酯通过Ni/光氧化还原催化的立体转化交叉偶联反应的α-选择性直接C-糖基化。在这里，我们报告了一种互补的立体保留合成方法，用于从类似的硼酸酯前体制备β-C-糖苷，通过添加C（sp2）阴离子，然后通过糖基供体的1，2-迁移。
C-Glycoside analogues of native glycans are useful molecular tools for medicinal chemistry and chemical biology due to their resistance to cellular glycoside hydrolases. We previously reported an α-selective direct C-glycosylation of 2-deoxy-β-glycosyl boronate through a Ni/photoredox-catalyzed stereoinvertive cross-coupling reaction. Here we report a complementary stereoretentive synthetic method for the preparation of β-C-glycosides from a similar boronate precursor through the addition of a C(sp2) anion followed by 1,2-migration of the glycosyl donor.