Selective ortho-Functionalization of Adamantylarenes Enabled by Dispersion and an Air-Stable Palladium(I) Dimer

Angew Chem Int Ed Engl. 2020 May 11;59(20):7721-7725. doi: 10.1002/anie.202001326. Epub 2020 Mar 17.

Abstract

Contrary to the general belief that Pd-catalyzed cross-coupling at sites of severe steric hindrance are disfavored, we herein show that the oxidative addition to C-Br ortho to an adamantyl group is as favored as the corresponding adamantyl-free system due to attractive dispersion forces. This enabled the development of a fully selective arylation and alkylation of C-Br ortho to an adamantyl group, even if challenged with competing non-hindered C-OTf or C-Cl sites. The method makes use of an air-stable PdI dimer and enables straightforward access to diversely substituted therapeutically important adamantylarenes in 5-30 min.

Keywords: DFT calculations; chemoselectivity; cross-coupling; homogeneous catalysis; palladium.