Silver-Catalyzed Oxidative Activation of Benzylic CH Bonds for the Synthesis of Difluoromethylated Arenes
作者:Peng Xu、Shuo Guo、Liyan Wang、Pingping Tang
DOI:10.1002/anie.201400225
日期:2014.6.2
A mild and catalytic method to form difluoromethylated arenes through the activation of benzylic CHbonds has been developed. Utilizing AgNO3 as the catalyst, various arenes with diverse functional groups undergo activation/fluorination of benzylic CHbonds with commercially available Selectfluor reagent as a source of fluorine in aqueous solution. The reaction is operationally simple and amenable
Iron-Catalyzed Difluoromethylation of Arylzincs with Difluoromethyl 2-Pyridyl Sulfone
作者:Wenjun Miao、Yanchuan Zhao、Chuanfa Ni、Bing Gao、Wei Zhang、Jinbo Hu
DOI:10.1021/jacs.7b11976
日期:2018.1.24
We report the first iron-catalyzed difluoromethylation of arylzincs with difluoromethyl2-pyridylsulfone via selective C-S bond cleavage. This method employs the readily available, bench-stable fluoroalkyl sulfone reagent and inexpensive iron catalyst, allowing facile access to structurally diverse difluoromethylated arenes at low temperatures. The experiment employing a radical clock indicates the
Room Temperature Deoxyfluorination of Benzaldehydes and α-Ketoesters with Sulfuryl Fluoride and Tetramethylammonium Fluoride
作者:Patrick R. Melvin、Devin M. Ferguson、Sydonie D. Schimler、Douglas C. Bland、Melanie S. Sanford
DOI:10.1021/acs.orglett.9b00054
日期:2019.3.1
A method for the room temperature deoxyfluorination of benzaldehydes and α-ketoesters using sulfurylfluoride and Me4NF is described. A large scope of aryl and heteroaryl substrates is demonstrated, and this method compares favorably to other common deoxyfluorination methods for many substrates.
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;
Deoxyfluorination of (Hetero)aryl Aldehydes Using Tetramethylammonium Fluoride and Perfluorobutanesulfonyl Fluoride or Trifluoromethanesulfonic Anhydride
作者:Devin M. Ferguson、Patrick R. Melvin、Melanie S. Sanford
DOI:10.1002/ijch.201900066
日期:2020.3
This Communication describes the conversion of (hetero)aryl aldehydes into the corresponding (hetero)aryl difluoromethyl products using anhydrous NMe4F in combination with perfluorobutanesulfonyl fluoride or trifluoromethanesulfonic anhydride.