Dimerization reactions with iron and cobalt bis(imino)pyridine catalysts: A substrate based approach

• Iron and cobalt bis(imino)pyridine catalysts show several substrate limitations.
• Product selectivities are influenced by structural and electronic substrate properties.
• Catalyst variations enable a cross dimerization of isobutene with propene.

Herein, we present a substrate based approach to gain insight into effects on reactivity as well as selectivity of dimerization reactions using bis(imino)pyridine catalysts. Common iron and cobalt systems show several limitations applying sterically demanding alkenes. Systematic substrate alterations reveal that structural properties are able to influence reactivity and dimer selectivity whereas electronic properties have an impact on insertion selectivity. Finally, successful conversion of the simplest vinylidene compound isobutene is achieved by catalyst variation.