The Cp2TiMe2-catalyzed intramolecular hydroamination/cyclization of aminoalkynes

Cp2TiMe2 has been found to be a competent catalyst for the intramolecular hydroamination/cyclization of aminoalkynes. In the presence of 5.0 mol% Cp2TiMe2, the hydroamination reactions proceed smoothly at 100–110°C to give five- and six-membered cyclic imines within 4–6 h. After subsequent reduction performed with zinc-modified NaBH3CN at room temperature cyclic amines can be isolated in good yields.