Heterocoupling of 2-naphthols enabled by a copper–N-heterocyclic carbene complex

Abstract

The reactivity of a Cu catalyst for oxidative coupling is modulated by a small molecule additive, diethyl malonate, that slows over-oxidation of 2-naphthols. Efficient heterocoupling between electron-rich and electron-poor 2-naphthols/2-naphthylamines affords C₁-symmetric BINOLs with yields ranging from 35–98%.