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。
Reaction of phenyl-substituted allyllithiums with tert-alkyl bromides. Remarkable difference in the alkylation regiochemistry between a polar process and the one involving single-electron transfer
Un chemin reactionnel polaire favorise l'attaque au niveau du site phenyl substitue (C-1) tandis qu'un couplage au niveau de l'autre site (C-3) se produit de facon predominante dans le cas d'un mecanisme SET
Un chemin reactnel polaire favourise l'attaque au niveau du site phenyl substitue (C-1) tandis qu'un couplage au niveau de l'autre site (C-3) se produit de facon predominante dans le cas d'un mecanisme SET
Visible light-driven conjunctive olefination
作者:Dario Filippini、Mattia Silvi
DOI:10.1038/s41557-021-00807-x
日期:2022.1
Here we report a visible-light-mediated and transition metal-free conjunctive olefination that uses an alkene ‘linchpin’ with a defined geometry to cross-couple complex molecular scaffolds that contain carboxylic acids and aldehydes. The chemistry merges two cornerstones of organic synthesis—namely, the Wittig reaction and photoredox catalysis—in a catalytic cycle that couples a radical addition process
Synthesis and Transformations of Aryl-Substituted Alkenes of the Adamantane Series
作者:S. A. Savel’eva、M. V. Leonova、M. R. Baimuratov、Yu. N. Klimochkin
DOI:10.1134/s1070428018070047
日期:2018.7
Aryl-substituted alkenes of the adamantane series, 1-[(Z,E)-3-phenylprop-2-en-1-yl]adamantane and 1-[(Z)-3-phenylprop-1-en-1-yl]adamantane, have been synthesized by the Wittig reaction. Their allylic bromination involves two concurrent reactions, radical substitution and raical addition. The different chemical behaviors of the aryl-substituted alkenes have been demonstrated in the Ritter reaction.