One-Step Deoxygenated Oxidative C–N Coupling of Azine N‑Oxides with Alicyclic Amines via Copper(I) Catalyst-dppf Cooperation

Transition
metal (TM)-catalyzed direct C–H amination on
free and fused pyridines is challenging, while it is much easier for
their N-oxide derivatives. Unfortunately, most TM-catalysis
is commonly used for nondeoxyamination and often limited to specific N-oxide and amine substrates. We herein disclose a combination
of a copper(I) catalyst and dppf for deoxygenated oxidative C–N
coupling of azine N-oxides to realize facile aminations
on their parent azines, wherein dppf plays a crucial role in the deoxygenation
step in the catalytic cycle. Moreover, this protocol tolerates a wider
variety of N-oxides and free alicyclic amines to
promise broader application potential.