Thermolysis of 2-(N-acylamino)benzyl methyl ethers, in the presence of an acid catalyst and triphenylphosphine, or 2-(N-acylamino)benzylphosphonium salts is found to serve as a novel method for indole formation, in particular for the synthesis of 2-trifluoromethylindoles. The reaction of the benzyl methyl ethers is suggested to involve a phosphonium intermediate, which thermally decomposes to the indoles.
The palladium-catalyzedannulation reaction of a variety of fluorine-containing internalalkynes with 2-iodoaniline derivatives took place smoothly to give the corresponding 2,3-disubstituted indol...
A Facile Regiocontrol in the Palladium-Catalyzed Annulation of Fluorine-Containing Internal Alkynes with Variously Substituted 2-Iodoanilines: A New Regioselective Synthesis of 2- or 3-Fluoroalkylated Indole Derivatives
Treatment of various types of fluoroalkylated alkynes with o-iodoaniline in the presence of Pd(PPh3)4 in DMF at 80 °C for 8 h mainly gave 2-fluoroalkylated indoles in high yields. The use of P(o-Tol)3 instead of PPh3 as a ligand led to the preferential formation of 3-fluoroalkylated indoles in high yields. Interestingly, the reaction of trifluoromethylated alkynes bearing a benzylic substituent afforded