Photo-induced Decarboxylative Heck-Type Coupling of Unactivated Aliphatic Acids and Terminal Alkenes in the Absence of Sacrificial Hydrogen Acceptors
作者:Hui Cao、Heming Jiang、Hongyu Feng、Jeric Mun Chung Kwan、Xiaogang Liu、Jie Wu
DOI:10.1021/jacs.8b11218
日期:2018.11.28
boronates are among the most versatile building blocks that can be found in every sector of chemical science. We herein report a noble-metal-free method of accessing such olefins through a photo-induced decarboxylative Heck-type coupling using alkyl carboxylic acids, one of the most ubiquitous building blocks, as the feedstocks. This transformation was achieved in the absence of external oxidants through
1,2-二取代的烯烃,如乙烯基芳烃、乙烯基硅烷和乙烯基硼酸酯,是化学科学各个领域中最通用的结构单元。我们在此报告了一种无贵金属的方法,该方法使用烷基羧酸(最普遍的结构单元之一)作为原料,通过光诱导脱羧 Heck 型偶联获得此类烯烃。这种转变是在没有外部氧化剂的情况下通过有机光氧化还原催化剂和钴肟催化剂的协同组合实现的,H2 和 CO2 作为唯一的副产物。控制实验和 DFT 计算都支持基于自由基的机制,最终导致开发出脂肪族羧酸、丙烯酸酯和乙烯基芳烃的选择性三组分偶联。
Iron-Catalyzed Vinylic C−H Alkylation with Alkyl Peroxides
作者:Liang Ge、Wujun Jian、Huan Zhou、Shaowei Chen、Changqing Ye、Fei Yu、Bo Qian、Yajun Li、Hongli Bao
DOI:10.1002/asia.201800534
日期:2018.9.4
are readily accessible from carboxylic acids, are utilized as general primary, secondary, and tertiary alkylating reagents for iron‐catalyzed vinylic C−H alkylation of vinyl arenes, dienes, and 1,3‐enynes. This transformation affords olefinic products in up to 98 % yield with high E/Z values. A broad range of functionalities, including carboxyl, boronic acid, methoxy, ester, amino, and halides, are
Tetrachlorophthalimides as Organocatalytic Acceptors for Electron Donor–Acceptor Complex Photoactivation
作者:Wei Zhou、Shuo Wu、Paolo Melchiorre
DOI:10.1021/jacs.2c03546
日期:2022.5.25
Excitation of photoactive electrondonor–acceptor (EDA) complexes is an effective way to generate radicals. Applications in a catalytic regime typically use catalytic donors. Herein, we report that readily available electron-poor tetrachlorophthalimides can act as effective organocatalytic acceptors to trigger the formation of EDA complexes with a variety of radical precursors not amenable to previous
Organophotocatalytic Radical–Polar Cross-Coupling of Styrylboronic Acids and Redox-Active Esters
作者:Allan J. B. Watson、Jeremy Brals、Nicholas D’Arcy-Evans、Thomas M. McGuire
DOI:10.1055/a-2179-6570
日期:2024.1
We report the development of a radical–polar cross-coupling reaction using styrylboronic acids and redox-active esters under organophotoredox catalysis. The reaction proceeds through a formal polarity-mismatched radical addition. The use of an organic photocatalyst permitted very low loadings of the electron-shuttle additive and accelerated reaction times compared with established processes. The scope
Rhodium‐Catalyzed Regio‐ and Diastereoselective [3+2] Cycloaddition of <i>gem</i>‐Difluorinated Cyclopropanes with Internal Olefins
作者:Yaxin Zeng、Ying Xia
DOI:10.1002/anie.202307129
日期:2023.8.7
A rhodium-catalyzed [3+2] cycloaddition reaction between readily available gem-difluorinated cyclopropanes and internal olefins has been developed, providing a wide range of multisubstituted gem-difluorinated cyclopentanes. This reaction shows an example where the “CF2” motif can be kept upon ring extension. The process is atom-economic and allows to reach numerous gem-difluorinated cyclopentanes with