Although aerobic oxidative acylation of amides with alcohols would be a good complement to classical synthetic methods for imides (e.g., acylation of amides with activated forms of carboxylic acids), to date, there have been no reports on oxidative acylation to produce imides. In this study, we successfully developed, for the first time, an efficient method for the synthesis of imides through aerobic oxidative acylation
尽管酰胺与醇的有氧氧化酰化是对酰亚胺的经典合成方法(例如,用活化形式的羧酸酰化酰胺)的良好补充,但迄今为止,还没有关于氧化酰化生产酰亚胺的报道。在本研究中,我们首次成功开发了一种采用 CuCl/TMEDA/nor-AZADO 催化剂体系(TMEDA = 四甲基乙二胺;nor-AZADO = 9-氮杂金刚烷N-氧基)。所提出的酰化通过以下顺序反应进行:醇有氧氧化成醛,酰胺与醛亲核加成形成半酰胺中间体,以及半酰胺中间体有氧氧化得到相应的酰亚胺。该催化系统利用O 2作为终端氧化剂并产生水作为唯一的副产物。实现这种有效酰化系统的一个重要点是TMEDA配体的利用,据我们所知,该配体尚未在之前报道的Cu/配体/ N-氧基系统中使用。基于实验证据,我们认为 TMEDA 的可能作用包括促进半酰胺氧化和从 Cu I物种再生活性 Cu II -OH 物种。这里促进半酰胺氧化尤其重要。利用所提出的系统,可以从醇
Cobalt-Catalyzed Selective Dearomatization of Pyridines to <i>N</i>–H 1,4-Dihydropyridines
作者:Maofu Pang、Le-Le Shi、Yufang Xie、Tianyi Geng、Lan Liu、Rong-Zhen Liao、Chen-Ho Tung、Wenguang Wang
DOI:10.1021/acscatal.2c00271
日期:2022.5.6
Catalyticreduction of pyridines to N–H 1,4-dihydropyridines is exceptionally challenging because they are essential intermediates to form tetrahydropyridines. Using a facile dihydrogen source H3N·BH3 to activate the pyridine ring in situ, we have achieved selective transfer hydrogenation of nicotinate derivatives to N–H 1,4-dihydropyridines by cobalt-amido cooperative catalysis. The reactions operate
in the structure of natural products and drugs, and play an important role in biological activities. However, due to the limitation of synthesis conditions, there are few studies on biscarbonyl diimides. In this paper, a series of newcompounds with diimide skeleton were synthesized by using CDI and NaH as condensation agents. The anti-inflammatory activity and cytotoxicity of the compound in RAW264
Aerobic Benzylic C(sp<sup>3</sup>)–H Bond Oxygenations Catalyzed by NBS under Visible Light Irradiation
作者:Taiqiang Ye、Yuzheng Li、Yanni Ma、Shenpeng Tan、Feng Li
DOI:10.1021/acs.joc.3c02284
日期:2024.1.5
An efficient photocatalytic oxidation of benzylic C(sp3)–H bonds to ketones, esters, and amides has been developed using NBS as a metal-free photocatalyst and O2 as an oxidant. A variety of synthetically and biologically valuable compounds are assembled in moderate to excellent yields. The synthetic utility of this approach has been demonstrated by gram-scale experiments. A possible free radical mechanism