1-/2-/3-Fluoroalkyl-substituted indoles, promising medicinally and biologically beneficial compounds: Synthetic routes, significance and potential applications

• Synthetic methods for the preparation of 1-RF-indoles were presented.
• Synthetic methods for the preparation of 2-RF-indoles were presented.
• Synthetic methods for the preparation of 3-RF-indoles were presented.
• Direct fluoroalkylation is widely used for the synthesis of RF-indoles.
• Significance of 1-/2-/3-RF-indoles was described.

Synthesis, significance and potential applications of such medicinally and biologically beneficial compounds as fluoroalkylated at the pyrrole moiety indoles (1-/2-/3-fluoroalkyl-substituted indoles) are described. Having various bioactive properties, RF-indoles are promising medicinally and biologically beneficial compounds. At present, known synthetic routes for the preparation of RF-indoles affect a fairly wide variety of advanced methods. These important substances can be synthesized either via direct fluoroalkylation or via procedures involving transformations of fluoroalkylated building-blocks. In direct fluoroalkylation (trifluoromethylation), indole and its derivatives were used in the reactions with such fluoroalkylating agents as fluoroalkyl halides, CF3CO2Na (in the presence of CuI), Ruppert–Prakash reagent (a Pd-catalyzed trifluoromethylation), CuI/FO2SCF2CO2Me. 2-CF3-4-pyrones can be used as trifluoromethylated building blocks for regioselective syntheses of CF3-indoles. Cyclizations of some RF-bearing ortho-disubstituted benzene derivatives allow preparation of various RF-indoles. Reactivity of the trifluoromethyl group and indole moiety of CF3-indoles is considered.

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