Carboxylic Acids as A Traceless Activation Group for Conjugate Additions: A Three-Step Synthesis of (±)-Pregabalin
作者:Lingling Chu、Chisa Ohta、Zhiwei Zuo、David W. C. MacMillan
DOI:10.1021/ja505964r
日期:2014.8.6
carboxylic acids as a traceless activation group for radical Michael additions has been accomplished via visible light-mediated photoredox catalysis. Photon-induced oxidation of a broad series of carboxylic acids, including hydrocarbon-substituted, α-oxy, and α-amino acids, provides a versatile CO2-extrusion platform to generate Michael donors without the requirement for organometallic activation or propagation
羧酸作为自由基迈克尔加成的无痕活化基团的直接应用是通过可见光介导的光氧化还原催化实现的。光子诱导氧化一系列广泛的羧酸,包括碳氢化合物取代的、α-氧基和 α-氨基酸,提供了一个多功能的 CO2 挤出平台来生成迈克尔供体,而无需有机金属活化或传播。多种迈克尔受体适用于这种新的共轭加成策略。还介绍了该技术在药物普瑞巴林(由辉瑞以商品名 Lyrica 商业化)的三步合成中的应用。
Decarboxylative Giese-Type Reaction of Carboxylic Acids Promoted by Visible Light: A Sustainable and Photoredox-Neutral Protocol
作者:Nieves P. Ramirez、Jose C. Gonzalez-Gomez
DOI:10.1002/ejoc.201601478
日期:2017.4.18
for decarboxylative generation of radicals from carboxylicacids and their 1,4-addition to Michael acceptors. The Fukuzumi catalyst ([Acr+-Mes]) enabled this transformation under visiblelight irradiation, at room temperature and with CO2 as the only byproduct. Scope and limitations of this protocol were examined using a range of Michael acceptors (15 examples) and a diverse array of carboxylic acids
这项工作描述了一种无过渡金属的方法,用于从羧酸中脱羧生成自由基及其与迈克尔受体的 1,4-加成。Fukuzumi 催化剂 ([Acr+-Mes]) 在可见光照射下、在室温下和 CO2 作为唯一副产物的情况下实现了这种转变。使用一系列迈克尔受体(15 个示例)和各种羧酸(18 个示例)检查了该协议的范围和限制。在该协议中使用 3-羟基新戊酸允许直接形成非对映异构纯 δ-内酯。此外,当使用高烯丙酸时,会发生自由基级联反应,形成三个 CC 键。
Photo-Mediated Decarboxylative Giese-Type Reaction Using Organic Pyrimidopteridine Photoredox Catalysts
作者:Firas El-Hage、Christopher Schöll、Jola Pospech
DOI:10.1021/acs.joc.0c01955
日期:2020.11.6
The decarboxylativeGiese-typereaction offers a versatile methodology for the radical alkylation of electron-deficient alkenes. Photo-mediated variants often require a pre-activation of carboxylicacids and/or employment of costly transition-metal photocatalysts. Herein, we present a metal-free photocatalyzed decarboxylativeGiese-type addition to electron-deficient alkenes using pyrimidopteridine
Hydroaminomethylation of Olefins with Aminomethyltrifluoroborate by Photoredox Catalysis
作者:Kazuki Miyazawa、Takashi Koike、Munetaka Akita
DOI:10.1002/adsc.201400556
日期:2014.9.15
A photocatalytic hydroaminomethylation of olefins with N‐protected aminomethyltrifluoroborates has been developed. This methodology provides a new strategy for the introduction of a primary aminomethyl group onto electron‐deficient CC bonds. This reaction constitutes a facile entry into synthetically useful γ‐aminobutyric acid (GABA) derivatives such as baclofen.
A simple generation method of carbon radicals via 1e-oxidation of organotrifluoroborates and carboxylic acids by the action of an organophotoredox catalyst, 9-mesityl-10-methylacridinium perchlorate ([Acr+–Mes]ClO4), has been developed. This organophotocatalytic protocol is amenable to radical C–C bond formation with electron-deficient olefins.