Condition-controlled divergent trifluoroalkylation: a diversity-oriented synthesis strategy for efficient construction of CF-decorated carbazole libraries.

A condition-controlled divergent trifluoroalkylation strategy for carbazole derivatives has been developed via alkylation with trifluoropyruvate. Employing trifluoroacetic acid (TFA) promoter, FeCl catalyst, or AgSbF catalyst, a wide scope of mono-trifluoromethylated carbazolylethanols (27 examples, up to 99% yield), di-trifluoromethylated carbazolylethanols (16 examples, up to 93% yield), and trifluoromethylated bis(carbazolyl)propionates (8 examples, up to 76% yield) were efficiently and selectively synthesized respectively for the first time. The features of these transformations include (1) precise control over product divergence through systematic condition modulation, (2) efficient construction of three distinct trifluoromethylated architectures from identical substrates, and (3) operational simplicity under mild reaction conditions. This work achieves the synthesis of a library of structurally diverse CF-decorated carbazole derivatives from the same set of readily available substrates through systematic modulation of reaction conditions. The strategy not only provides a versatile platform for synthesizing fluorinated carbazole architectures but also inspires future exploration of condition-driven diversity-oriented synthesis (DOS) of carbazole derivatives with tailored functional groups for applications in medicinal chemistry and materials science.