The catalytic transfer hydrogenation of imines and the reductive amination of carbonyl compounds have been thoroughly investigated with a cyclooctene‐derived (cyclopentadienone)iron pre‐catalyst. Additionally, enantioselective ketimine reduction with a chiral (cyclopentadienone)ironcomplex is reported here for the first time.
Carbon dioxide promoted reductive amination of aldehydes in water mediated by iron powder and catalytic palladium on activated carbon
作者:Ran Ma、Yue-Biao Zhou、Liang-Nian He
DOI:10.1016/j.cattod.2016.01.048
日期:2016.10
catalytic palladium on activatedcarbon has been developed for reductiveamination of various aromatic aldehydes, including 2-pyridinecarboxaldehyde, in water under CO2 atmosphere. The reversible reaction of CO2 with water could form carbonic acid and hydrogen transfer from water to Pd(0) took place with the presence of iron powder, leading to formation of high-active Pd hydrides for the reductive amination
The reduction of imines to amines via transfer hydrogenation was achieved promoted by phosphine‐free manganese(I) catalyst. Using isopropanol as reductant, in the presence of tBuOK (4 mol %) and manganese complex [Mn(CO)3Br(κ2N,N‐PyCH2NH2)] (2 mol %), a large variety of aldimines (30 examples) were typically reduced in 3 hours at 80 °C with good to excellent yield.
Dual Role of Acetate in Copper(II) Acetate Catalyzed Dehydrogenation of Chelating Aromatic Secondary Amines: A Kinetic Case Study of Copper‐Catalyzed Oxidation Reactions
作者:Kesavapillai Sreenath、Zhao Yuan、Miguel Macias‐Contreras、Vasanth Ramachandran、Ronald J. Clark、Lei Zhu
DOI:10.1002/ejic.201600540
日期:2016.8
dehydrogenation of chelating aromatic secondary amines. The chemoselectivity of acetate and chelating amines in this reaction provides a unique opportunity for a mechanistic study. The progression of this homogeneous reaction is monitored by using electron paramagnetic resonance spectroscopy, UV/Vis absorption spectroscopy, and manometry. The kinetic dependence on the amine substrate, copper(II), and
醋酸铜 (II) 是铜 (II) 介导的氧化还原反应中铜源的常见经验选择。醋酸盐反离子的影响似乎很关键,但尚未得到充分研究。在此,我们报告乙酸铜(II)催化螯合芳香仲胺的有氧脱氢。该反应中乙酸盐和螯合胺的化学选择性为机理研究提供了独特的机会。通过使用电子顺磁共振光谱、UV/Vis 吸收光谱和测压法监测这种均相反应的进程。对胺底物、铜 (II) 和醋酸盐反离子的动力学依赖性,以及动力学同位素和取代基效应实验的结果,表明醋酸盐既可以作为双核催化中心的桥接配体来介导双电子转移步骤,又可以作为限制周转的 C-H 键断裂步骤中的碱基。在包含 1,8-二氮杂双环 [5.4.0] undec-7-ene (DBU) 作为替代碱后,DBU 和乙酸盐以互补的方式起作用,以实现螯合仲胺底物的快速催化脱氢反应。最后,醋酸铜(II)(促进双电子转移)和高氯酸铜(II)(促进单电子转移)之间的对比反应性强调了抗衡离
Nucleophilic Aromatic Substitution of Unactivated Fluoroarenes Enabled by Organic Photoredox Catalysis
作者:Vincent A. Pistritto、Megan E. Schutzbach-Horton、David A. Nicewicz
DOI:10.1021/jacs.0c09296
日期:2020.10.7
use of organic photoredox catalysis renders this method operationally simple under mild conditions and is amenable to various nucleophile classes, including azoles, amines, and carboxylic acids. Select fluorinated heterocycles can be functionalized using this method. In addition, the late-stage functionalization of pharmaceuticals is also presented. Computational studies demonstrate that the site selectivity