402-54-0Relevant articles and documents
Aromatic trifluoromethylation catalytic in copper
Oishi, Masahiro,Kondo, Hideaki,Amii, Hideki
, p. 1909 - 1911 (2009)
Cu(i)-diamine complexes were found to catalyse the trifluoromethylation of aryl iodides. In the presence of a small amount of CuX (X = Cl, Br, I) and 1,10-phenanthroline (phen), the cross-coupling reactions of iodoarenes with trifluoromethylsilanes proceeded smoothly to afford trifluoromethylated aromatics in good yields.
Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
, p. 15396 - 15405 (2021/10/12)
In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e? redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: i) easy AgI/AgIII 2e? oxidation mediated by air; ii) bpy/phen ligation to AgIII; iii) boron-to-AgIII aryl transfer; and iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]? (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]? intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.
Solvated Nickel Complexes as Stoichiometric and Catalytic Perfluoroalkylation Agents**
Shreiber, Scott T.,Vicic, David A.
supporting information, p. 18162 - 18167 (2021/07/14)
The acetonitrile-solvated [(MeCN)Ni(C2F5)3]? was prepared in order to compare and contrast its reactivity with the known [(MeCN)Ni(CF3)3]? towards organic electrophiles. Both [(MeCN)Ni(CF3)3]? and [(MeCN)Ni(C2F5)3]? successfully react with aryl iodonium and diazonium salts as well as alkynyl iodonium salts to give fluoroalkylated organic products. Electrochemical analysis of [(MeCN)NiII(C2F5)3]? suggests that, upon electro-oxidation to [(MeCN)nNiIII(C2F5)3], reductive homolysis of a perfluoroethyl radical occurs, with the concomitant formation of [(MeCN)2NiII(C2F5)2]. Catalytic C?H trifluoromethylations of electron-rich arenes were successfully achieved using either [(MeCN)Ni(CF3)3]? or the related [Ni(CF3)4]2?. Stoichiometric reactions of the solvated nickel complexes reveal that “ligandless” nickel is exceptionally capable of serving as reservoir of CF3 groups under catalytically relevant conditions.
