Rhodium(III)‐Catalyzed Asymmetric Access to Spirocycles through C−H Activation and Axial‐to‐Central Chirality Transfer
作者:Lingheng Kong、Xi Han、Song Liu、Yun Zou、Yu Lan、Xingwei Li
DOI:10.1002/anie.202000174
日期:2020.4.27
Axial-to-central chirality transfer is an important strategy to construct chiral centers, where the axiallychiral reagents are mostly limited to atropomerically stable ones. Reported herein is a RhIII -catalyzed enantioselective spiroannulative synthesis of nitrones. The coupling proceeds via C-Harylation to give an atropomerically metastable biaryl, followed by intramolecular dearomative trapping
A [4+1] Cyclative Capture Approach to 3
<i>H</i>
‐Indole‐
<i>N</i>
‐oxides at Room Temperature by Rhodium(III)‐Catalyzed CH Activation
作者:Yaxi Yang、Xuan Wang、Yuanchao Li、Bing Zhou
DOI:10.1002/anie.201508702
日期:2015.12.14
The rhodium(III)‐catalyzed [3+2] CH cyclization of aniline derivatives and internal alkynes represents a useful contribution to straightforward synthesis of indoles. However, there is no report on the more challenging synthesis of pharmaceutically important N‐hydroxyindoles and 3H‐indole‐N‐oxides. Reported herein is the first rhodium(III)‐catalyzed [4+1] CH oxidative cyclization of nitrones with
gold and chiral phosphoric acid cooperatively catalyzed enantioselective oxidative cyclization/Mannich-type addition reaction of homopropargyl amides with nitrones has been developed, which provides chiral pyrrolidin-3-ones in high yields with excellent enantioselectivities under mild conditions. This reaction employed stable and readily available alkynes as non-diazo carbene precursors, which provides
Highly atom efficient synthesis of 2,2,4,5-tetrasubstituted 3(2<i>H</i>)-furanones having both hydroxyl and amino substituents
作者:Jesna Antony、Sumi P. Musthafa、Rakesh Natarajan、Sindhu Mathai、Karakkattu S. Devaky、John P. Rappai
DOI:10.1080/00397911.2022.2036347
日期:2022.2.16
Abstract We have developed a highly atom efficient synthesis of tetrasubstituted 3(2H)-furanones from easily accessible starting materials such as C,N-diarylaldonitrones and dibenzoylacetylene. Control experiments revealed that reaction of aldonitrones having electron-withdrawing groups on the C-aryl substituent in polar aprotic solvents exhibited high product selectivity while reaction temperature
摘要 我们已经开发出一种高效的四取代 3(2 H )-呋喃酮合成方法,该合成方法由容易获得的起始材料(如C,N-二芳基醛固酮和二苯甲酰基乙炔)构成。对照实验表明,在C-芳基取代基上具有吸电子基团的醛固酮在极性非质子溶剂中的反应表现出高产物选择性,而反应温度对产物收率和选择性的影响可忽略不计。
NO Cations as Highly Efficient Catalysts for Carbon–Carbon Bond Forming Reactions
作者:Yasuhiro Yamashita、Shū Kobayashi
DOI:10.1246/cl.2009.678
日期:2009.7.5
NO cations were found to be a highly effective catalysts in several carbon–carbon bond forming reactions. For example, [3+2] cycloadditions of nitrones or azomethine imines with vinylethers procee...
发现 NO 阳离子是几种碳-碳键形成反应中的高效催化剂。例如,硝酮或偶氮甲亚胺与乙烯基醚的 [3+2] 环加成反应...