The C–H amination of electron-deficientarenes such as polyfluoroarenes and azole compounds with O-acylated hydroxylamines effectively proceeds in the presence of a copper catalyst even at room temperature to provide the corresponding anilines and aminoazoles in good yields.
Perfluoropyridine as an Efficient, Tunable Scaffold for Bis(pyrazol‐1‐yl)pyridine Copper Complexes
作者:Andrew J. Peloquin、Matthew B. Houck、Colin D. McMillen、Scott T. Iacono、William T. Pennington
DOI:10.1002/ejic.202000150
日期:2020.5.14
This report details the syntheses of five new 2,6‐bis(pyrazol‐1‐yl)pyridine ligands carried out by a unique strategy of utilizing pentafluoropyridine for the pyridine core. Formation of each ligand is accomplished under mild conditions utilizing carbonate bases. Each ligand reacts readily with copper(II) triflate to form the corresponding salt in high yield. Ligands and complexes were characterized
Fluorinated Aminopyridines: Synthesis, Structure, and Rare Liquid–Liquid Cocrystal Formation Driven by Unusually Short N–H···F–C Hydrogen Bonding
作者:Andrew J. Peloquin、Daniel A. Kure、Abby R. Jennings、Colin D. McMillen、Scott T. Iacono、William T. Pennington
DOI:10.1021/acs.cgd.0c00689
日期:2020.8.5
The role of hydrogen bonding in the crystalpacking of a series of 4-aminoperfluoropyridines was studied using single-crystal X-ray crystallography. The aminoperfluoropyridines were synthesized using only excess amine to serve as both nucleophile and base. Instead of addition to the perfluoropyridine ring, a strong N–H···F–C hydrogen bond led to cocrystal formation of perfluoropyridine with sterically
A copper-catalyzed electrophilic, umpolung amination strategy for the direct C-H amination of polyfluoroarenes and 1,3-azoles has been developed. The copper-based amination reaction is robust and can be easily scaled up on a gram scale. Its application to an annulative electrophilic amination of o-alkynylphenols and -anilines for the synthesis of 3-aminobenzofurans and -indoles is also described.
Radical <i>ipso</i>-Substitution of a Carbon–Fluorine Bond Leading to Fluoro-7-azaindolines and Fluoro-7-azaindoles
作者:Zhibo Liu、Ling Qin、Samir Z. Zard
DOI:10.1021/ol500985f
日期:2014.5.16
Rare examples of a synthetically useful radical ipso-substitution of a carbon–fluorine bond are reported, leading to highly functionalized 5,6-difluoro-7-azaindolines. An unexpected hydrogen atom translocation and fragmentation with loss of molecular nitrogen and formation of a nitrile were observed in the case of an N-benzyl-tetrazole derivative.