An experimentalist’s guide to electrosynthesis: the Shono oxidation
摘要:
Electrosynthesis is a powerful method to functionalise organic molecules without the need to use chemical reagents or protecting groups, yet it is not widely used in synthesis. In this study, we investigated the Shono oxidation of a tertiary amide (electrochemical functionalisation of a C-H bond adjacent to an amide nitrogen atom), demonstrating the value of performing cyclic voltammetry, varying voltage and charge per mole, selection of electrolyte and electrode material. We demystify the process to demonstrate a simple relationship between oxidation potential, and charge transfer required, which affords a high conversion to the desired alpha-methoxylated product using an undivided experimental cell. (C) 2015 Elsevier Ltd. All rights reserved.
A convenient synthesis of N -vinyl enamides via the lithiation and ring-opening reaction of 2-phenyl-2-oxazolines
作者:Yi Xu、Xiao-Yu Liu、Zi-Qi Wang、Liang-Fu Tang
DOI:10.1016/j.tetlet.2017.03.080
日期:2017.5
A simple and efficient synthesis of N-vinyl enamides via the lithiation and ring-openingreaction of 2-phenyl-2-oxazolines with lithium diisopropylamide at room temperature has been developed. This method is especially suitable for the synthesis of multifunctional enamides. Good yields have been obtained when the reactions were amplified to gram scale.
corresponding saturated counterparts by the dehydrogenative strategy are a dream reaction that has remained largely underexplored. In this report, a straightforward and robust cobaloxime-catalyzed photochemical dehydrogenation strategy via intramolecular HAT is described for the first time. The reaction proceeds through an intramolecular radical translocation followed by the cobalt assisted dehydrogenation without
通过脱氢策略从相应的饱和对应物中直接去除氢的转变是一个梦想的反应,但在很大程度上仍未得到充分探索。在本报告中,首次描述了一种通过分子内 HAT 的简单而稳健的钴肟催化光化学脱氢策略。该反应通过分子内自由基易位进行,然后进行钴辅助脱氢,不需要任何其他外部光敏剂、贵金属或氧化剂。通过这种方法,以中等至优异的产率获得了一系列有价值的不饱和化合物,例如α,β-不饱和酰胺、烯酰胺以及烯丙型和高烯丙型磺酰胺,具有良好的化学和区域选择性,并且通过一系列转化证明了合成的多功能性。并讨论了该方法的机理研究。
Photoredox Catalytic Access to <i>N</i>,<i>O</i>‐Acetals from Enamides by Means of Electron‐Poor Perylene Bisimides
Enamides can be converted into their N,O-acetals using just electron-poor perylene bisimides together with light, without the need for thiophenol as additive or strong acids as catalyst.