4-氧代-4 H -1-苯并吡喃在C-3处具有甲酰基,乙酰基或羧基取代基的异二烯环加成反应会生成3-烷氧基-或3,3-二烷氧基-4, 4a-二氢吡喃并[4,3- b ] [1]苯并吡喃-10-酮,在某些情况下,能够在多种条件下进行多种选择性转化,包括酸诱导的差向异构和/或逆环加成,还原,水解和醇解非常温和的条件。
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。