hydroacylation reaction of alkenes has been achieved employing readily available carboxylicacids as the acyl source and hydrosilanes as a hydrogen source via photoredox catalysis. The combination of both single electron transfer and hydrogen atom transfer steps has dramatically expanded new applications of carboxylicacids in organic synthesis. The protocol also features extremely mild conditions, broad
Acyl Radicals from α-Keto Acids Using a Carbonyl Photocatalyst: Photoredox-Catalyzed Synthesis of Ketones
作者:Da-Liang Zhu、Qi Wu、David James Young、Hao Wang、Zhi-Gang Ren、Hong-Xi Li
DOI:10.1021/acs.orglett.0c02351
日期:2020.9.4
Acylradicals have been generated from α-keto acids using inexpensive and commercially available 2-chloro-thioxanthen-9-one as the photoredox catalyst under visible light illumination. These reactive species added to olefins or coupled with aryl halides via a bipyridyl-stabilized Ni(II) catalyst, enabling easy access to a diverse range of ketones. This reliable, atom-economical, and eco-friendly protocol
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。
Cu(OAc)<sub>2</sub>-Triggered Cascade Reaction of Malonate-Tethered Acyl Oximes with Indoles, Indole-2-alcohols, and Indole-2-carboxamides
作者:Peng-Fei Mao、Li-Jin Zhou、An-Qi Zheng、Chun-Bao Miao、Hai-Tao Yang
DOI:10.1021/acs.orglett.9b00849
日期:2019.5.3
indole-2-carboxmides provides facile access to polysubstituted 3-pyrrolin-2-ones. The reaction features the generation of two adjacent electrophilic centers at the same time as cyclization to lactam. The subsequent double addition with nucleophiles followed by oxidation realizes the difunctionalization of the imine sp2-carbon and the adjacent α-sp3-carbon.
Decarboxylative 1,4-Addition of α-Oxocarboxylic Acids with Michael Acceptors Enabled by Photoredox Catalysis
作者:Guang-Zu Wang、Rui Shang、Wan-Min Cheng、Yao Fu
DOI:10.1021/acs.orglett.5b02392
日期:2015.10.2
Enabled by iridium photoredoxcatalysis, 2-oxo-2-(hetero)arylacetic acids were decarboxylatively added to various Michael acceptors including α,β-unsaturated ester, ketone, amide, aldehyde, nitrile, and sulfone at room temperature. The reaction presents a new type of acyl Michael addition using stable and easily accessible carboxylicacid to formally generate acyl anion through photoredox-catalyzed