Zinc amidinate-catalysed cyclization reaction of carbodiimides and alkynes. An insight into the mechanism.

A synthesis of iminopyridines based on zinc has been developed. The commercially available ZnEt 2 was employed as a precatalyst for this process. A mechanism has been proposed on the basis of Density Functional Theory (DFT) studies and stoichiometric reactions. The zinc amidinato intermediates underscore the critical role of zinc in this synthesis process.