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
Chemoselective synthesis of ketones and ketimines by addition of organometallic reagents to secondary amides
作者:William S. Bechara、Guillaume Pelletier、André B. Charette
DOI:10.1038/nchem.1268
日期:2012.3
is of great importance, as this motif serves as a synthetic handle for the elaboration of numerous organic functionalities. In this context, we report a general and chemoselective method based on an activation/addition sequence on secondaryamides allowing the controlled isolation of structurally diverse ketones and ketimines. The generation of a highly electrophilic imidoyl triflate intermediate was
method for CF3-containing oxazolines via trifluoromethylation of allylamides by using Togni reagent in the presence of alkali metal iodides, which play a key role in selective production of the desired oxazoline. The reaction did not proceed efficiently with copper catalysts commonly used for oxytrifluoromethylations. Our method afforded a wide variety of CF3-containing oxazolines, which are potential candidates
Toward a General Protocol for Catalytic Oxidative Transformations Using Electrochemically Generated Hypervalent Iodine Species
作者:Mohamed Elsherbini、Wesley J. Moran
DOI:10.1021/acs.joc.2c02309
日期:2023.2.3
addition, no added electrolytic salts are needed in this process. The developed method has been validated using two different hypervalent iodine-mediated transformations: (i) the oxidative cyclization of N-allylic and N-homoallylic amides to the corresponding dihydrooxazole and dihydro-1,3-oxazine derivatives, respectively, and (ii) the α-tosyloxylation of ketones. Both reactions proceeded smoothly under
已经开发了一种用于由高价碘试剂介导的氧化转化的简单催化电合成方案。在该协议中,电力驱动碘 (I)/碘 (III) 催化循环,使原位产生的高价碘物种能够进行催化,从而消除化学氧化剂和与其作用方式相关的不可避免的化学废物。此外,在此过程中不需要添加电解质盐。所开发的方法已使用两种不同的高价碘介导的转化进行了验证:(i)N-烯丙基和N的氧化环化- 高烯丙基酰胺分别生成相应的二氢恶唑和二氢-1,3-恶嗪衍生物,以及 (ii) 酮的 α-甲苯磺酰氧基化。两个反应在开发的催化电合成条件下顺利进行,无需重新优化,具有广泛的底物范围和优异的官能团耐受性。此外,可以轻松实现克级放大和催化剂回收,从而保持工艺的高效率。