Fluorine-Directed Glycosylation
Fluorine-Directed Glycosylation
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DOI：
10.1002/anie.201004467
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Gilmour, Ryan
中科院分区：
文献类型：
--
作者：
Bucher, Christoph;Gilmour, Ryan
碳水化合物在自然界中普遍存在，从细胞能量来源到基于表面的分子识别的调节剂。[1]不出所料，这些功能性生物分子一直是激烈的合成活动的主题，最终导致大量糖基化方法，这些方法适用于复杂寡糖的立体控制合成。[2]几乎所有这些策略的核心都是一个中间体氧鎓离子，其构象在决定新形成的异头中心的构型方面具有决定性作用。[3]然而，以可预测的方式控制氧鎓离子构象是具有挑战性的，[4]特别是对于2-脱氧糖，其中不能调节C2处的保护基方案以控制立体选择性。[5]认识到有机氟化合物倾向于采用允许稳定超共轭和吸引静电相互作用的构象，[6]我们设想来自2-氟吡喃糖的瞬时氧鎓离子（I！II）将是有趣的候选人进行调查（方案1）。
Carbohydrates are ubiquitous in nature, ranging from cellular energy sources to modulators of surface-based molecular recognition.[1] Unsurprisingly, these functional biomolecules have been the subject of intense synthesis campaigns culminating in a vast arsenal of glycosylation methods that are amenable to the stereocontrolled synthesis of complex oligosaccharides.[2] Central to virtually all of these strategies is an intermediary oxonium ion, the conformation of which is decisive in determining the configuration of the newly formed anomeric center.[3] However, controlling oxonium ion conformation in a predictable manner is challenging,[4] especially for 2-deoxy sugars where the protecting group regime at C2 cannot be modulated to govern stereoselectivity.[5] Cognisant of the tendency of organofluorine compounds to adopt conformations that allow for stabilizing hyperconjugative and attractive electrostatic interactions,[6] we envisaged that the transient oxonium ions derived from 2-fluoropyranoses (I! II) would be intriguing candidates for investigation (Scheme 1).