Electrochemical oxidative radical cascade cyclization of olefinic amides and thiophenols towards the synthesis of sulfurated benzoxazines, oxazolines and iminoisobenzofurans
containing N and O are important structures in pharmaceuticals, agrochemicals and functional molecules. The synthesis of these compounds usually requires complex substrates and harsh reaction conditions. Herein, we introduce a mild and efficient electrochemical oxidative strategy to construct benzoxazines, oxazolines and iminoisobenzofurans without the requirement of a transition-metal catalyst and an
含 N 和 O 的杂环是药物、农用化学品和功能分子中的重要结构。这些化合物的合成通常需要复杂的底物和苛刻的反应条件。在此,我们引入了一种温和有效的电化学氧化策略来构建苯并恶嗪、恶唑啉和亚氨基异苯并呋喃,而无需过渡金属催化剂和外部氧化剂。在一个简单的未分开的细胞中,各种烯酰胺和苯硫酚/二硒化物反应生成 69 个硫醇化和硒化杂环的例子,产率高达 83%。此外,这种自由基级联反应为一步构建 C-S/C-Se 和 C-O 键提供了一种简便的方法。
Microwave-assisted, Mo(CO)6-mediated, palladium-catalyzed amino-carbonylation of aryl halides using allylamine: from exploration to scale-up
作者:Prasad Appukkuttan、Linda Axelsson、Erik Van der Eycken、Mats Larhed
DOI:10.1016/j.tetlet.2008.07.053
日期:2008.9
Palladium-catalyzed aminocarbonylations of various (hetero)aryl halides with allylamine usingMo(CO)6 as a solid, in situ CO source, were explored. Microwave-enhanced conditions proved to be highly useful in promoting the conversions in a mere 10–20 min with various (hetero)aryliodides, bromides and chlorides. The scale-up of a microwave-enhanced aminocarbonylation to 25 mmol scale was performed successfully
Flow electrochemistry: a safe tool for fluorine chemistry
作者:Bethan Winterson、Tim Rennigholtz、Thomas Wirth
DOI:10.1039/d1sc02123k
日期:——
The heightened activity of compounds containing fluorine, especially in the field of pharmaceuticals, provides major impetus for the development of new fluorination procedures. A scalable, versatile, and safe electrochemical fluorination protocol is conferred. The strategy proceeds through a transient (difluoroiodo)arene, generated by anodic oxidation of an iodoarene mediator. Even the isolation of
含氟化合物的活性增强,特别是在制药领域,为新氟化工艺的开发提供了主要动力。提供了一种可扩展、通用且安全的电化学氟化方案。该策略通过碘芳烃介体的阳极氧化产生瞬态(二氟碘)芳烃来进行。甚至二氟化碘( III )的分离也很容易,因为电解是在没有其他试剂的情况下进行的。通过将电解步骤与流动中的下游反应耦合,以高产率实现了广泛的高价碘介导的反应,超越了间歇化学的限制。(二氟碘)芳烃有毒且化学不稳定,因此不间断生成和立即流动使用非常有利。高流速使生产率高达 834 mg h -1,同时大大缩短了反应时间。集成到全自动机器和在线淬火是减少氢氟酸使用带来的危害的关键。
Electrochemical oxidative cyclization of olefinic carbonyls with diselenides
作者:Zhipeng Guan、Yunkun Wang、Huamin Wang、Yange Huang、Siyuan Wang、Hongding Tang、Heng Zhang、Aiwen Lei
DOI:10.1039/c9gc02665g
日期:——
The tandem cyclization of olefinic carbonyls with easily accessible diselenides facilitated by electrochemical oxidation has been successfully developed, which provides an environmentally friendly method for the construction of C–Se and C–O bonds simultaneously. A series of seleno dihydrofurans and seleno oxazolines, bearing fragile heterocycles, subtle C–I bonds and supernumerary vinyl groups, were
5-aminoisoxazolines via tandem catalytic isomerization (of N-allyl systems to N-(1-propenyl) systems)—1,3-dipolar cycloaddition (of a stable nitrileoxide to N-(1-propenyl) systems) is presented. Rhodium and ruthenium complexes, Verkade’s superbase, and 18-crown-6/KOH system were used for the syntheses of the N-(1-propenyl) systems. 4-P-substituted isoxazoline was also synthesized via cycloaddition of