Ureate Titanium Catalysts for Hydroaminoalkylation: Using Ligand Design to Increase Reactivity and Utility

Abstract

Hydroaminoalkylation describes the atom-economical catalytic synthesis of amines by forming new Csp3–Csp3 bonds using readily available amine and alkene feedstocks. Herein, we describe an earth-abundant and cost-efficient titanium catalyst generated in situ using commercially available Ti(NMe2)4 and a simple to synthesize urea proligand. This system demonstrates high TOFs for hydroaminoalkylation with unactivated substrates and features easy to use commercially available titanium amido precursors. Additionally, a high catalytic activity, scope of reactivity, and regioselectivity are all demonstrated in the transformation of unactivated terminal olefins with various alkyl and aryl secondary amines. Finally, syntheses of useful amine-containing monomers suitable for the generation of amine-containing materials, as well as amine-containing building blocks for medicinal chemistry, are disclosed. These preparative methods avoid the necessity of glovebox techniques and are modified to be useful to all synthetic chemists.