Nickel-Catalyzed Aromatic Cross-Coupling Difluoromethylation of Grignard Reagents with Difluoroiodomethane
作者:Hirotaka Motohashi、Koichi Mikami
DOI:10.1021/acs.orglett.8b02264
日期:2018.9.7
The nickel-catalyzed cross-coupling difluoromethylation of the Grignardreagents with difluoroiodomethane is shown to provide the corresponding aromatic difluoromethyl products in excellent to moderate yields. The difluoromethylation proceeds smoothly within 1 h at room temperature with 1.5 equiv of the Grignardreagents in the presence of Ni(cod)2/TMEDA (2.5–0.5 mol %). Mechanistic studies clarify
Electrochemical-Promoted Nickel-Catalyzed Oxidative Fluoroalkylation of Aryl Iodides
作者:Zhenlei Zou、Heyin Li、Mengjun Huang、Weigang Zhang、Sanjun Zhi、Yi Wang、Yi Pan
DOI:10.1021/acs.orglett.1c02997
日期:2021.11.5
This work describes a general strategy for metal-catalyzed cross-coupling of fluoroalkyl radicals with aryl halides under electrochemical conditions. The contradiction between anodic oxidation of fluoroalkyl sulfinates and cathodic reduction of low-valentnickel catalysts can be well addressed by paired electrolysis, allowing for direct introduction of fluorinated functionalities into aromatic systems
Ligand-Less Iron-Catalyzed Aromatic Cross-Coupling Difluoromethylation of Grignard Reagents with Difluoroiodomethane
作者:Hirotaka Motohashi、Miki Kato、Koichi Mikami
DOI:10.1021/acs.joc.9b00585
日期:2019.5.17
Iron-catalyzed cross-coupling difluoromethylations of the Grignardreagents with difluoroiodomethane provide various aromatic difluoromethyl products in good yields, not employing sterically demanding ligands. Difluoromethylations proceed within 30 min at −20 °C with 2.0 equiv of the Grignardreagents and FeCl3 or Fe(acac)3 (2.5 mol %). Mechanistic investigations clarify difluoromethyl radical intervention;
Access to Difluoromethylated Arenes by Pd-Catalyzed Reaction of Arylboronic Acids with Bromodifluoroacetate
作者:Zhang Feng、Qiao-Qiao Min、Xingang Zhang
DOI:10.1021/acs.orglett.5b03206
日期:2016.1.4
of aryl boronic acids with bromodifluoroacetate is described. The reaction proceeds under mild reaction conditions with hydroquinone and Fe(acac)3 as additives. Preliminary mechanistic studies reveal that a difluorocarbene pathway is involved in the reaction, which is unusual compared to the most traditional approaches. This reaction has advantages of high efficiency and excellent functional group compatibility
represents the ideal and most straightforward difluoromethylating reagent, but introduction of the difluoromethyl group (CF2H) from ClCF2H into aromatics has not been reported. Here, we describe a direct palladium-catalysed difluoromethylation method for coupling ClCF2H with arylboronic acids and esters to generate difluoromethylated arenes with high efficiency. The reaction exhibits a remarkably broad substrate