Just a pinch of copper iodide promotes the reaction of manno-type glycosyl iodides with lithiated dithianes. Herein, we report an efficient and highly α-selective four-step one-pot method for the synthesis of unprotected manno-type C-acyl pyranosides. The crucial role of the catalyst was proven by mechanistic studies and DFT calculations, suggesting a copper-radical mechanism over a SN-type mechanism
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碘化
铜即可促进甘露型糖基
碘化物与
锂化二噻烷的反应。在此,我们报告了一种高效且高 α 选择性的四步一锅法,用于合成无保护的甘露型C-酰基
吡喃糖苷。催化剂的关键作用已通过机理研究和 DFT 计算得到证明,表明
铜自由基机理优于 S N型机理。