Abstract
Herein, we report a new hydroaminative cyclization for 1,6 and 1,7 en-ynes using a simple Ti imido precatalyst, [py(2)TiCl(2)(NPh)](2). The well-known Ti imido + alkyne [2+2] azatitanacyclobutadiene cycloadduct intermediate can be further intercepted via insertion by tethered alkenes, followed by protonolysis of the resultant metallacycle to yield α-carbocyclic imine products through cascading C-N and C-C bond formation.