Organosodium compounds for catalytic cross-coupling

Abstract

Sodium is the most abundant alkali metal in the Earth’s crust and the ocean. However, organosodium compounds have long been considered inferior to organolithium compounds, which have instead dominated synthetic organic chemistry during the last century. Despite being largely neglected because of their reactive nature, it is worth re-exploring organosodium chemistry, in light of the growing demand for sustainable syntheses without recourse to less abundant elements such as lithium. Herein, we demonstrate that, contrary to common belief, organosodium compounds can be easily prepared from aryl chlorides or (hetero)arenes and easy-to-handle sodium dispersion and, after being transmetallated to the corresponding zinc and boron compounds, they readily participate in the Negishi and Suzuki–Miyaura cross-coupling reactions, fundamental carbon–carbon bond-forming reactions in organic synthesis. Direct coupling reactions with organosodium species were also possible. While organolithium and organomagnesium compounds have well developed methods in organic chemistry, organosodium compounds are much less widely used. Here a method to generate organosodium compounds from aryl chlorides and (hetero)arenes is reported, along with a demonstration of their use in cross-coupling reactions.