Bromotrifluoromethane, electrochemical

The electrochemical reduction of bromotrifluoromethane (CF3Br) in DMF in a cell fitted with a sacrificial zinc anode and a stainless steel or nickel cathode is a typical case where the organometallic compound formation can be realized according to two different processes, and where a transient species having a different reactivity compared to usual organometallics can be produced. 

Trifluoromethyl)trimethylsilane is a highly useful trifluoromethylating reagent. Efficient electrochemical trimethylsilylation of bromotrifluoromethane has been developed (equation 84)108. 

Another method of trifluoromethylation was based on the electrochemical reaction (copper anode) of 2-bromothiophene 94 with bromotrifluoromethane in DMF. In comparison to usual methods leading to trifluoromethylcopper, this one offered an advantage because it allowed the use of CFsBr instead of the more expensive CF3I. However, the reaction was not selective and gave a mixture of 2- and 3-isomers 78 and 79. The use of 2-iodothiophene 38 as a starting material was found to be more effective 2-trifluoromethylthiophene 78 was obtained in 60 % yield [57],... 

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