A Mild meta-Selective C–H Alkylation of Catechol Mono-Ethers

Catechol mono-ethers are an important class of phenols. They are found in a number of pharmaceuticals, flavoring agents, perfumes, and are used for the preparation of numerous drugs. Herein, we report a mild meta-selective C–H alkylation of these phenols, which is enabled by a cascade of oxidative dearomatization – radical addition – rearomatization process. The method is compatible with reactive functional groups on the parent arenol, such as olefins and halides. Primary, secondary, and teriary alkyl groups can be used, the source of which is most commonly an alkylborane. This process is operationally simple, does not require heating and generally proceeds in good yields.