Organic compounds bearing a CF₃ substituent, especially on an aromatic ring are in exceedingly high demand as building blocks for the needs of agrochemical, pharmaceutical, and materials industries. While considerable progress has been made in the area of Cu-mediated aromatic trifluoromethylation, very little has been done in order to understand its mechanism. The present work reports the first combined experimental and computational studies aimed specifically at the elucidation of the mechanism of trifluoromethylation of haloarenes. The employed CuCF₃ reagent was prepared by the new reaction of direct cupration of fluoroform. As this remarkable transformation is unprecedented itself, detailed studies of its mechanism were also performed. In addition, a long-known yet poorly understood accelerating effect of the ortho-substituent in Cu-promoted coupling reactions was studied by experimental and computational means. Finally, an extensive theoretical investigation of the electronic properties of the CF₃ group was carried out. Evidently, this subject matter is highly relevant to understanding the reaction mechanisms and further development in the area of trifluoromethylation reactions.