Incorporation of carbon dioxide into phthalides via ligand-free copper-catalyzed direct carboxylation of benzoxasiloles
作者:Thanh V. Q. Nguyen、José A. Rodríguez-Santamaría、Woo-Jin Yoo、Shū Kobayashi
DOI:10.1039/c7gc00917h
日期:——
The directcarboxylation of benzoxasiloles with carbondioxide proceeded smoothly under mild conditions using copper iodide as a catalyst to afford phthalides after an acid work-up. Broad substrate scope and application of this methodology for the synthesis of natural products highlight the synthetic utility of this protocol.
iron/photoredox dual-catalyzed acyl nitrene formation and the use of acyl nitrene in constructing various C–O bonds towards phthalides. The developed reaction starts from N-methoxyl-2-alkylbenzamides. Mechanism surveys suggest the reaction involves iron nitrene-based hydrogen atom abstraction (HAA), radical-polar crossover and O-nucleophilic SN1. Distinctively, the often-reported radical rebound in previous publications
本文描述了铁/光氧化还原双催化酰基氮烯的形成以及酰基氮烯在构建各种 C-O 键中对苯酞的应用。开发的反应从N -methoxyl-2-alkylbenzamides 开始。机理调查表明,该反应涉及基于铁氮烯的氢原子提取 (HAA)、自由基-极性交叉和O-亲核 S N 1。值得注意的是,未观察到以前出版物中经常报道的自由基反弹。该反应代表了基于酰基氮烯的苯酞合成的第一个例子。此外,它还作为合成3-丁基苯酞(NBP)、沙利度胺、Pomalyst和Otezia等市售药物的补充剂。
Verwendung von 3,6-Dimethyl-2-(3H)-benzofuranon als Aromastoff und ein neues Verfahren zu seiner Herstellung
申请人:HAARMANN & REIMER GMBH
公开号:EP0953294A3
公开(公告)日:2003-07-23
3,6-Dimethyl-2(3H)-benzofuranon ist ein neuer, wertvoller Aromastoff, welcher in Nahrungs-, Genuß- und Mundpflegemitteln eingesetzt werden kann. Es wurde ein Verfahren für eine technische Herstellung entwickelt.
A straightforward synthesis of (S)-3-methylphthalides has been developed, with the key asymmetric step being the bioreduction of 2-acetylbenzonitriles. Enzymatic processes have been found to be highly dependent on the pH value, with acidic conditions being required to avoid undesired side reactions. Baker's yeast was found lobe the best biocatalyst acting in a highly stereoselective fashion. The simple treatment of the reaction crudes with aqueous HCl has provided access to enantiopure (S)-3-methylphthalides in moderate to excellent yields.
Palladium-Catalyzed Decarboxylative <i>Ortho</i>-Ethoxycarbonylation of <i>O</i>-Methyl Ketoximes and 2-Arylpyridines with Potassium Oxalate Monoester
作者:Zhong-Yuan Li、Guan-Wu Wang
DOI:10.1021/acs.orglett.5b02422
日期:2015.10.2
A novel method for introducing an ester group via palladium-catalyzed ligand-directed C-H activation has been explored. The ortho-ethoxycarbonylation of O-methyl ketoximes proceeded smoothly with the nontoxic and easily handled reagent potassium oxalate monoester, affording the desired products in moderate to good yields. Furthermore, pyridine could also be employed as a directing group to obtain similar results in this transformation.