Alkyne Carboamination with Imines Catalyzed by [py2TiCl2N(p-tol)]2

Abstract

α,β-Unsaturated imines are valuable functional groups that lack a general, reliable synthetic route. Here, we report that simple Ti imido halide precatalysts of the type [py₂TiCl₂N(Ar)]₂ can catalyze alkyne carboamination with imines, yielding highly substituted α,β-unsaturated imines. [py₂TiCl₂N(Ar)]₂ complexes can catalyze an expanded scope of substrates relative to earlier-reported cationic Ti complexes, albeit with modest yields. Several key side products of carboamination have been identified, indicating that low-valent Ti species resulting from catalyst decomposition may be limiting productive catalysis.