One-Pot Synthesis of Fluorinated 1-Benzoyl-3,4-dihydroisoquinolines from [2-(o-Alkynylphenyl)ethyl]amines by a Hydroamination/Oxidation Sequence



Fluorinated 1-benzoyl-3,4-dihydroisoquinolines can easily be synthesized by a new one-pot procedure from corresponding fluorinated [2-(o-alkynylphenyl)ethyl]amines in high yields. The one-pot process consists of an initial [Ind2TiMe2]-catalyzed intramolecular alkyne hydroamination and a subsequent Pd-catalyzed oxidation of the benzyl side chain of the resulting hydroamination product. The process tolerates electron-donating and -withdrawing substituents on the benzene ring that is converted into the benzoyl side chain of the products as well as ortho-substitution.