- Mild C?F Activation in Perfluorinated Arenes through Photosensitized Insertion of Isonitriles at 350 nm
-
Fluorinated compounds have become important in the fields of agrochemical industry, pharmaceutical chemistry and materials sciences. Accordingly, various methods for their preparation have been developed in the past. Fluorinated compounds can be accessed via conjugation with fluorinated building blocks, via C?H fluorination or via selective activation of perfluorinated compounds to give the partially fluorinated congeners. Especially the direct activation of C?F bonds, one of the strongest σ-bonds, still remains challenging and new strategies for C?F activation are desirable. Herein a method for the photochemical activation of aromatic C?F bonds is presented. It is shown that isonitriles selectively insert into aromatic C?F bonds while aliphatic C?F bonds remain unaffected. Mechanistic studies reveal the reaction to proceed via the indirect excitation of the isonitrile to its triplet state by photoexcited acetophenone at 350 nm. Due to the relatively mild light used, the process shows high functional group tolerance and various compounds of the class of benzimidoyl fluorides are accessible from aryl isonitriles and commercially available perfluorinated arenes. (Figure presented.).
- Weidlich, Frauke,Esumi, Naoto,Chen, Dongyang,Mück-Lichtenfeld, Christian,Zysman-Colman, Eli,Studer, Armido
-
supporting information
p. 376 - 383
(2019/11/19)
-
- Silver-Catalyzed Chemoselective [4+2] Annulation of Two Isocyanides: A General Route to Pyridone-Fused Carbo- and Heterocycles
-
A silver-catalyzed chemoselective [4+2] annulation of aryl and heteroaryl isocyanides with α-substituted isocyanoacetamides was developed for the facile and efficient synthesis of 2-aminoquinolones, naphthyridines, and phenanthrolines. A mechanism for this multistep domino reaction is proposed on the basis of a13C-labeling experiment, according to which an unprecedented chemoselective heterodimerization of two different isocyanides generates an α-amidoketenimine intermediate, which undergoes 1,3-amino migration to form an α-imidoylketene, followed by 6 π electrocyclization.
- Hu, Zhongyan,Dong, Jinhuan,Men, Yang,Lin, Zhichen,Cai, Jinxiong,Xu, Xianxiu
-
supporting information
p. 1805 - 1809
(2017/02/05)
-
- Photoaffinity-labeled peptoids and depsipeptides by multicomponent reactions
-
Photoaffinity tags can be incorporated easily into peptoids and congeners by the Ugi and Passerini multicomponent reactions. Products related to photo-methionine and photo-leucine can be accomplished by diazirine-containing building blocks. The same proto
- Henze, Michael,Kreye, Oliver,Brauch, Sebastian,Nitsche, Christoph,Naumann, Kai,Wessjohann, Ludger A.,Westermann, Bernhard
-
experimental part
p. 2997 - 3003
(2010/10/21)
-
- A Convenient Preparation of Functionalized Arylzinc Compounds by the Reaction of Zinc/Silver-Graphite with Aryl Iodides.
-
Aryl- and hetero-aryl iodides react under very mild conditions (THF, 25 deg C) with a Zn(Ag) couple deposited on graphite leading to the corresponding zinc reagents in excellent yields.In the presence of CuCN*2LiCl or catalytic amounts of Pd(O), these unsaturated zinc species can be acylated, allylated or coupled with iodoalkenes.
- Fuerstner, Alois,Singer, Robert,Knochel, Paul
-
p. 1047 - 1050
(2007/10/02)
-