TiCl4/t-BuNH2 as the sole catalyst for a hydroamination-based Fischer indole synthesis

A system comprising TiCl4 and t-BuNH2 acts as a catalyst for highly regioselective hydroamination reactions of alkynes using hydrazines and at the same time a Lewis acid in the transformation of the generated hydrazones into indole derivatives, while a 1,3-diyne is converted to pyrroles using the same precatalyst.