heterocyclic N‐oxides with N‐hydroxyphthalimide esters was developed using Eosin Y as the photocatalyst in the presence of Cs2CO3 under redox‐neutral and mild conditions. Using N‐hydroxyphthalimide esters as the radicalprecursors, quinoline and pyridine N‐oxides were readily coupled with a wide range of primary, secondary, and tertiary radicals to afford the desired alkylated heterocyclic N‐oxides in moderated
使用曙红Y作为光催化剂,在Cs 2 CO 3存在下,开发了可见光诱导的杂环N-氧化物与N-羟基邻苯二甲酰亚胺酯的CH选择性烷基化烷基化反应在氧化还原中性和温和条件下。使用N-羟基邻苯二甲酰亚胺酯作为自由基前体,喹啉和吡啶N-氧化物易于与各种伯,仲和叔基团偶联,以中等至极好的收率提供所需的烷基化杂环N-氧化物。重要的是,该反应方案还成功证明了其在糖基或生物活性天然脱氢松香酸含杂环N-氧化物以及药物和农用化学活性烷基化奎宁基功能分子(潜在的抗疟药)的构建中的应用。
Coupling of Nitrogen Heteroaromatics and Alkanes without Transition Metals: A New Oxidative Cross-Coupling at CH/CH Bonds
作者:Guojun Deng、Kirika Ueda、Shuichi Yanagisawa、Kenichiro Itami、Chao-Jun Li
DOI:10.1002/chem.200801893
日期:2009.1.2
Look—no transition metal! Transition‐metal‐free systems for the direct cross‐coupling reactions of nitrogen heteroaromatics and alkanes are described. Under the influence of tBuOOtBu, pyridine N‐oxide derivatives react with alkanes to furnish the corresponding cross‐coupling products (alkylated nitrogen heterocycles) in good yields.
看,没有过渡金属!描述了用于氮杂芳烃和烷烃直接交叉偶联反应的无过渡金属体系。在t BuOO t Bu的影响下,吡啶N-氧化物衍生物与烷烃反应,以高收率提供相应的交叉偶联产物(烷基化氮杂环)。
Decarboxylative C–H Alkylation of Heteroarene <i>N</i>-Oxides by Visible Light/Copper Catalysis
This paper reports a highly site-selective alkylation of heteroarene N-oxides using hypervalent iodine(III) carboxylates to serve as an alkylating agent in the presence of a cheap copper catalyst under visible light conditions. This mild method proceeds at room temperature in an air atmosphere and can withstand various heteroarene N-oxides as well as various primary, secondary, and tertiary alkyl carboxylic
Palladium-Catalyzed C–H Activation/Cross-Coupling of Pyridine <i>N</i>-Oxides with Nonactivated Secondary Alkyl Bromides
作者:Bin Xiao、Zhao-Jing Liu、Lei Liu、Yao Fu
DOI:10.1021/ja3113752
日期:2013.1.16
activation/C-C cross-coupling reaction has been found to occur between pyridine N-oxides and general nonactivated secondary and even tertiary alkylbromides. It provides a practically useful approach for the synthesis of alkylated pyridine derivatives. Experimental observations indicated that the C-Br cleavage step involves a radical-type process. Thus, the title reaction provides a rather extraordinary