Dialkyl Ether Formation by Nickel-Catalyzed Cross-Coupling of Acetals and Aryl Iodides

A new substrate class for nickel-catalyzed C(sp(3)) cross-coupling reactions is reported. alpha-Oxy radicals generated from benzylic acetals, TMSCl, and a mild reductant can participate in chemoselective cross-coupling with aryl iodides using a 2,6-bis(N-pyrazolyl)pyridine (bpp)/Ni catalyst. The mild, base-free conditions are tolerant of a variety of functional groups on both partners, thus representing an attractive C-C bond-forming approach to dialkyl ether synthesis. Characterization of a [(bpp)NiCl] complex relevant to the proposed catalytic cycle is also described.