Hubei Key Laboratory of Natural Products Research and Development, Key Laboratory of Functional Yeast (China National Light Industry), College of Biological and Pharmaceutical Sciences, China Three Gorges University, Yichang 443002, P. R. China.
J Org Chem. 2023 Aug 18;88(16):11735-11747. doi: 10.1021/acs.joc.3c01011. Epub 2023 Jul 31.
Borate esters have been applied widely as coupling partners in organic synthesis. However, the direct utilization of borate acceptors in -glycosylation with glycal donors remains underexplored. Herein, we describe a novel -glycosylation resulting in the formation of 2,3-unsaturated -glycosides and 2-deoxy -glycosides mediated by palladium and copper catalysis, respectively. This -glycosylation method tolerated a broad scope of trialkyl/triaryl borates and various glycals with exclusive stereoselectivities in high yields. All the desired aliphatic/aromatic -glycosides and 2-deoxy -glycosides were generated successfully, without the hemiacetal byproducts and O→C rearrangement because of the nature of borate esters. The utility of this strategy was demonstrated by functionalizing the 2,3-unsaturated glycoside products to form saturated β--glycosides, 2,3-deoxy -glycosides, and 2,3-epoxy -glycosides.
硼酸酯被广泛应用于有机合成中的偶联剂。然而，硼酸受体在与糖醛供体的 -糖苷化反应中的直接利用仍未得到充分探索。在此，我们描述了一种新型的 -糖苷化反应，分别通过钯和铜催化形成 2,3-不饱和 -糖苷和 2-脱氧 -糖苷。这种 -糖苷化方法对各种三烷基/三芳基硼酸酯和多种糖醛具有广泛的适用性，以高收率获得了独特的立体选择性。所有所需的脂肪族/芳族 -糖苷和 2-脱氧 -糖苷都成功地生成，由于硼酸酯的性质，没有半缩醛副产物和 O→C 重排。该策略的实用性通过将 2,3-不饱和糖苷产物官能化来形成饱和β--糖苷、2,3-脱氧 -糖苷和 2,3-环氧 -糖苷得到了证明。
