3CF3

3CF3 is a chemical notation used to indicate the presence of a trifluoromethyl substituent (CF3) at the third position of a parent molecule, most commonly on an aromatic ring. In practice, it denotes meta-substitution relative to a reference substituent on a benzene ring, and it appears in systematic or semi-systematic naming when describing substituted arenes or heterocycles.

In nomenclature, 3CF3 is used to describe the position of the CF3 group without specifying the entire framework of the molecule. For example, in a disubstituted benzene, a CF3 group at position 3 relative to another group would be described as a 3-CF3 derivative. The term is thus a positional descriptor rather than a standalone compound.

Trifluoromethyl groups are strongly electron-withdrawing by induction and can influence the physical and chemical properties of the molecule. A CF3 substituent typically increases lipophilicity and metabolic stability, often decreases the basicity of nearby amine nitrogens, and can alter reactivity and director effects in electrophilic aromatic substitution, generally favoring meta substitution patterns.

Methods to install CF3 groups on arenes or heterocycles include electrophilic trifluoromethylation and nucleophilic trifluoromethylation, using specialized reagents such as electrophilic Togni or Umemoto reagents, or nucleophilic sources like Ruppert–Prakash reagent (Me3SiCF3) with catalytic systems. These approaches enable the synthesis of 3-CF3 derivatives for applications in pharmaceuticals, agrochemicals, and materials science.

See also: trifluoromethyl group, trifluoromethylation, meta-substitution, aromatic fluorination.