88-16-4Relevant articles and documents
Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
supporting information, 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.
Novel synthesis method of chlorobenzotrifluoride
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Paragraph 0015-0023, (2020/01/14)
The invention discloses a novel synthesis method of chlorobenzotrifluoride, wherein o-chlorotoluene is used as a raw material, copper chloride or cuprous chloride is used as a catalyst, and o-chlorobenzotrifluoride is synthesized through two steps of chlorination and fluorination. Compared with the method in the prior art, the method of the invention has the following characteristics that raw materials are subjected to heating dehydration treatment in the dehydration kettle, so that the chlorination side reactions are few, the product purity is high, the graded chlorination device does not need to be additionally arranged, the technological process is simple, and the operation is convenient. According to the chlorination process of the invention, the catalyst is added in batches to increase the efficiency of the catalyst, so that the by-product generated by thechlorination reaction and the emission of waste gas in the production are greatly reduced, and the emission of pollutants in the production process is reduced.
Au@ZnO Core-Shell: Scalable Photocatalytic Trifluoromethylation Using CF3CO2Na as an Inexpensive Reagent under Visible Light Irradiation
Bazyar, Zahra,Hosseini-Sarvari, Mona
supporting information, p. 2345 - 2353 (2019/10/16)
Trifluoromethylation is of significant importance for the synthesis of many small molecules vital for medicinal and agrochemical research. The importance of the CF3 group as well as the related synthetic challenges is so evident that many reagents have been reported for the synthesis of trifluoromethylated compounds, but these typical reagents are expensive and the methods for preparing them are difficult. Here, we report a new scalable and operationally simple trifluoromethylation reaction using sodium trifluoroacetate as a reagent and Au-modified ZnO as a photocatalyst under visible light irradiation. The reaction proceeds via trifluoromethylation of a broad range of aryl halides, arylboronic acids, and arene and heteroarene substrates. Some pharmaceutical and agrochemical compounds have been trifluoromethylated directly to demonstrate the applicability of the method.
