Metal-Free Direct C-H β-Carbonyl Alkylation of Heteroarenes with Cyclopropanols Mediated by K<sub>2</sub>
S<sub>2</sub>
O<sub>8</sub>
作者:Qiang Liu、Qiang Wang、Guanqun Xie、Zeyang Fang、Shujiang Ding、Xiaoxia Wang
DOI:10.1002/ejoc.202000289
日期:2020.5.10
direct C–H β‐carbonyl alkylation of heteroarenes has been achieved through K2S2O8‐mediated ring‐opening of cyclopropanols. A wide scope of substrates, such as various substituted quinolines and isoquinolines, pyridines, pyridazine, benzo[d]thiazole, and phenanthroline, underwent the β‐carbonyl alkylation efficiently and afforded the β‐heteroarylated ketones in moderate to excellent yields.
Copper-mediated tandem ring-opening/cyclization reactions of cyclopropanols with aryldiazonium salts: synthesis of <i>N</i>-arylpyrazoles
作者:Jidan Liu、Erjie Xu、Jinyuan Jiang、Zeng Huang、Liyao Zheng、Zhao-Qing Liu
DOI:10.1039/c9cc09657d
日期:——
A general method for the synthesis of structurally diverse N-arylpyrazoles from readily available cyclopropanols and aryldiazonium salts is disclosed. The reaction was conducted at room temperature within minutes with a broad substrate scope and excellent regioselectivity.
Aryl Pyrazoles from Photocatalytic Cycloadditions of Arenediazonium
作者:Luana Cardinale、Michael Neumeier、Michal Majek、Axel Jacobi von Wangelin
DOI:10.1021/acs.orglett.0c02514
日期:2020.9.18
conditions (rt, 20 min) with catalytic [Ru(bpy)3]2+ under blue-light irradiation and exhibited compatibility with several functional groups (e.g., I, SF5, SO2NH2, N3, CN) and perfect levels of regiocontrol. Mechanistic studies (luminescence spectroscopy, CV, DFT, radical trapping, quantum yield determination) documented an initial oxidative quenching of the excited photocatalyst and the operation of
centered around ring-opening carbon–carbon bond cleavage/fluorination of strained cycloalkanols, either using precious silver catalysis or superstoichiometric ceric ammonium nitrate (CAN). Careful study of these methods has allowed us to design and develop a general Earth-abundant-element-catalyzed method for remotely fluorinated ketone synthesis via C–C bond cleavage. Critically, the use of manganese