Investigating Oxidative Addition Mechanisms of Allylic Electrophiles with Low-Valent Ni/Co Catalysts Using Electroanalytical and Data Science Techniques
作者:Tianhua Tang、Eli Jones、Thérèse Wild、Avijit Hazra、Shelley D. Minteer、Matthew S. Sigman
DOI:10.1021/jacs.2c09120
日期:2022.11.2
the critical oxidative addition mechanism to form the π-allyl-Co/Ni complex remains unclear. Herein, we present a study to investigate this process with four catalysis-relevant complexes: Co(MeBPy)Br2, Co(MePhen)Br2, Ni(MeBPy)Br2, and Ni(MePhen)Br2. Enabled by an electroanalytical platform, Co(I)/Ni(I) species were found responsible for the oxidative addition of allylacetate. Kinetic features of different
由于在还原性 Co/Ni 催化的烯丙基化反应中具有独特的反应性,π-烯丙基-Co/Ni 络合物的催化作用最近引起了广泛关注。尽管在反应开发方面取得了重大成功,但形成 π-烯丙基-Co/Ni 络合物的关键氧化加成机制仍不清楚。在此,我们提出了一项研究,用四种与催化相关的配合物研究该过程:Co( Me BPy)Br 2、Co( Me Phen)Br 2、Ni( Me BPy)Br 2和 Ni( Me Phen)Br 2. 通过电分析平台,发现 Co(I)/Ni(I) 物种负责乙酸烯丙酯的氧化加成。通过线性自由能关系(Hammett 型)研究、统计建模和 DFT 计算研究来表征不同底物的动力学特征。在此过程中,提出了配位电离型过渡态,与 Tsuji-Trost 反应中 Pd(0) 介导的氧化加成具有相似的特征。计算和配体结构分析研究支持这一机制,这将为下一代催化剂的开发提供关键信息。
Photoinduced Hydrodifluoromethylation and Hydromethylation of Alkenes Enabled by Ligand-to-Iron Charge Transfer Mediated Decarboxylation
Directly utilizing abundant and inexpensive sources of aliphatic carboxylic acids is highly attractive for the synthesis of CF2H- and CH3-containing compounds. Herein, we report a versatile photoinduced iron-catalyzed platform for hydrodifluoromethylation and hydromethylation of alkenes without the need of additional stoichiometric oxidants. These two transformations are accomplished by a visible-light-induced
Atmospheric Oxygen Mediated Radical Hydrothiolation of Alkenes
作者:Ruairí O. McCourt、Eoin M. Scanlan
DOI:10.1002/chem.202002542
日期:2020.12.4
hydrothiolation of alkenes (and alkyne) is reported. A variety of sulfur containing motifs including alkanethiols, thiophenols and thioacids undergo an atmospheric oxygen‐mediated radical hydrothiolation reaction with a plethora of alkenes in good yield with excellent functional group compatibility, typically with short reaction times to furnish a range of functionalized products. Biomolecules proved
Reacting Molecular Oxygen with Butanone under Visible Light Irradiation: A General Aerobic Oxidation of Alkenes, Sulfides, Phosphines, and Silanes
作者:Pengcheng Lian、Kaifeng Wang、Hang Liu、Ruyi Li、Minggang Li、Xiaoguang Bao、Xiaobing Wan
DOI:10.1021/acs.orglett.3c03096
日期:2023.11.10
technique by reacting molecularoxygen with butanone under visible lightirradiation. This method enables the mild oxidation of various functionalized compounds, including olefins, sulfides, phosphines, and silanes. Preliminary mechanistic experiments and theoretical calculations suggest that visible light triggers molecularoxygen to produce singlet oxygen in butanone. This singlet oxygen then reacts with